DESC ia64 CONFIG_LOCKMETER fix EDESC From: John Hawkes The 2.6.3-mm4 patch seems to have the CONFIG_LOCKMETER in the wrong spot for ia64. When I make this change, I can build and run an ia64 Lockmeter'ed kernel. --- 25-akpm/arch/i386/Kconfig | 7 25-akpm/arch/i386/lib/dec_and_lock.c | 3 25-akpm/arch/ia64/Kconfig | 7 25-akpm/arch/ia64/lib/dec_and_lock.c | 2 25-akpm/arch/sparc64/Kconfig | 9 25-akpm/arch/sparc64/lib/rwlock.S | 15 25-akpm/fs/proc/proc_misc.c | 37 + 25-akpm/include/asm-alpha/lockmeter.h | 84 ++ 25-akpm/include/asm-alpha/spinlock.h | 50 + 25-akpm/include/asm-i386/lockmeter.h | 115 +++ 25-akpm/include/asm-i386/spinlock.h | 69 + 25-akpm/include/asm-ia64/lockmeter.h | 72 + 25-akpm/include/asm-ia64/spinlock.h | 73 + 25-akpm/include/asm-mips/lockmeter.h | 126 +++ 25-akpm/include/asm-mips/spinlock.h | 9 25-akpm/include/asm-sparc64/lockmeter.h | 45 + 25-akpm/include/asm-sparc64/spinlock.h | 42 - 25-akpm/include/linux/lockmeter.h | 320 ++++++++ 25-akpm/include/linux/spinlock.h | 146 +++ 25-akpm/kernel/Makefile | 1 25-akpm/kernel/lockmeter.c | 1178 ++++++++++++++++++++++++++++++++ 21 files changed, 2399 insertions(+), 11 deletions(-) diff -puN arch/i386/Kconfig~lockmeter arch/i386/Kconfig --- 25/arch/i386/Kconfig~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/arch/i386/Kconfig Fri May 14 17:40:32 2004 @@ -1280,6 +1280,13 @@ config DEBUG_INFO Say Y here only if you plan to use gdb to debug the kernel. If you don't debug the kernel, you can say N. +config LOCKMETER + bool "Kernel lock metering" + depends on SMP + help + Say Y to enable kernel lock metering, which adds overhead to SMP locks, + but allows you to see various statistics using the lockstat command. + config DEBUG_SPINLOCK_SLEEP bool "Sleep-inside-spinlock checking" help diff -puN arch/i386/lib/dec_and_lock.c~lockmeter arch/i386/lib/dec_and_lock.c --- 25/arch/i386/lib/dec_and_lock.c~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/arch/i386/lib/dec_and_lock.c Fri May 14 17:40:32 2004 @@ -10,6 +10,7 @@ #include #include +#ifndef ATOMIC_DEC_AND_LOCK int atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) { int counter; @@ -38,3 +39,5 @@ slow_path: spin_unlock(lock); return 0; } +#endif + diff -puN arch/sparc64/Kconfig~lockmeter arch/sparc64/Kconfig --- 25/arch/sparc64/Kconfig~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/arch/sparc64/Kconfig Fri May 14 17:40:32 2004 @@ -687,12 +687,19 @@ config DEBUG_BOOTMEM depends on DEBUG_KERNEL bool "Debug BOOTMEM initialization" +config LOCKMETER + bool "Kernel lock metering" + depends on SMP && !PREEMPT + help + Say Y to enable kernel lock metering, which adds overhead to SMP locks, + but allows you to see various statistics using the lockstat command. + # We have a custom atomic_dec_and_lock() implementation but it's not # compatible with spinlock debugging so we need to fall back on # the generic version in that case. config HAVE_DEC_LOCK bool - depends on SMP && !DEBUG_SPINLOCK + depends on SMP && !DEBUG_SPINLOCK && !LOCKMETER default y config MCOUNT diff -puN arch/sparc64/lib/rwlock.S~lockmeter arch/sparc64/lib/rwlock.S --- 25/arch/sparc64/lib/rwlock.S~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/arch/sparc64/lib/rwlock.S Fri May 14 17:40:32 2004 @@ -85,5 +85,20 @@ __write_trylock_succeed: __write_trylock_fail: retl mov 0, %o0 + + .globl __read_trylock +__read_trylock: /* %o0 = lock_ptr */ + ldsw [%o0], %g5 + brlz,pn %g5, 100f + add %g5, 1, %g7 + cas [%o0], %g5, %g7 + cmp %g5, %g7 + bne,pn %icc, __read_trylock + membar #StoreLoad | #StoreStore + retl + mov 1, %o0 +100: retl + mov 0, %o0 + rwlock_impl_end: diff -puN fs/proc/proc_misc.c~lockmeter fs/proc/proc_misc.c --- 25/fs/proc/proc_misc.c~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/fs/proc/proc_misc.c Fri May 14 17:40:32 2004 @@ -655,6 +655,36 @@ static void create_seq_entry(char *name, entry->proc_fops = f; } +#ifdef CONFIG_LOCKMETER +extern ssize_t get_lockmeter_info(char *, size_t, loff_t *); +extern ssize_t put_lockmeter_info(const char *, size_t); +extern int get_lockmeter_info_size(void); + +/* + * This function accesses lock metering information. + */ +static ssize_t read_lockmeter(struct file *file, char *buf, + size_t count, loff_t *ppos) +{ + return get_lockmeter_info(buf, count, ppos); +} + +/* + * Writing to /proc/lockmeter resets the counters + */ +static ssize_t write_lockmeter(struct file * file, const char * buf, + size_t count, loff_t *ppos) +{ + return put_lockmeter_info(buf, count); +} + +static struct file_operations proc_lockmeter_operations = { + NULL, /* lseek */ + read: read_lockmeter, + write: write_lockmeter, +}; +#endif /* CONFIG_LOCKMETER */ + void __init proc_misc_init(void) { struct proc_dir_entry *entry; @@ -725,6 +755,13 @@ void __init proc_misc_init(void) if (entry) entry->proc_fops = &proc_sysrq_trigger_operations; #endif +#ifdef CONFIG_LOCKMETER + entry = create_proc_entry("lockmeter", S_IWUSR | S_IRUGO, NULL); + if (entry) { + entry->proc_fops = &proc_lockmeter_operations; + entry->size = get_lockmeter_info_size(); + } +#endif #ifdef CONFIG_PPC32 { extern struct file_operations ppc_htab_operations; diff -puN /dev/null include/asm-alpha/lockmeter.h --- /dev/null Thu Apr 11 07:25:15 2002 +++ 25-akpm/include/asm-alpha/lockmeter.h Fri May 14 17:40:32 2004 @@ -0,0 +1,84 @@ +/* + * Written by John Hawkes (hawkes@sgi.com) + * Based on klstat.h by Jack Steiner (steiner@sgi.com) + * + * Modified by Peter Rival (frival@zk3.dec.com) + */ + +#ifndef _ALPHA_LOCKMETER_H +#define _ALPHA_LOCKMETER_H + +#include +#define CPU_CYCLE_FREQUENCY hwrpb->cycle_freq + +#define get_cycles64() get_cycles() + +#define THIS_CPU_NUMBER smp_processor_id() + +#include + +#define SPINLOCK_MAGIC_INIT /**/ + +/* + * Macros to cache and retrieve an index value inside of a lock + * these macros assume that there are less than 65536 simultaneous + * (read mode) holders of a rwlock. + * We also assume that the hash table has less than 32767 entries. + * the high order bit is used for write locking a rw_lock + * Note: although these defines and macros are the same as what is being used + * in include/asm-i386/lockmeter.h, they are present here to easily + * allow an alternate Alpha implementation. + */ +/* + * instrumented spinlock structure -- never used to allocate storage + * only used in macros below to overlay a spinlock_t + */ +typedef struct inst_spinlock_s { + /* remember, Alpha is little endian */ + unsigned short lock; + unsigned short index; +} inst_spinlock_t; +#define PUT_INDEX(lock_ptr,indexv) ((inst_spinlock_t *)(lock_ptr))->index = indexv +#define GET_INDEX(lock_ptr) ((inst_spinlock_t *)(lock_ptr))->index + +/* + * macros to cache and retrieve an index value in a read/write lock + * as well as the cpu where a reader busy period started + * we use the 2nd word (the debug word) for this, so require the + * debug word to be present + */ +/* + * instrumented rwlock structure -- never used to allocate storage + * only used in macros below to overlay a rwlock_t + */ +typedef struct inst_rwlock_s { + volatile int lock; + unsigned short index; + unsigned short cpu; +} inst_rwlock_t; +#define PUT_RWINDEX(rwlock_ptr,indexv) ((inst_rwlock_t *)(rwlock_ptr))->index = indexv +#define GET_RWINDEX(rwlock_ptr) ((inst_rwlock_t *)(rwlock_ptr))->index +#define PUT_RW_CPU(rwlock_ptr,cpuv) ((inst_rwlock_t *)(rwlock_ptr))->cpu = cpuv +#define GET_RW_CPU(rwlock_ptr) ((inst_rwlock_t *)(rwlock_ptr))->cpu + +/* + * return true if rwlock is write locked + * (note that other lock attempts can cause the lock value to be negative) + */ +#define RWLOCK_IS_WRITE_LOCKED(rwlock_ptr) (((inst_rwlock_t *)rwlock_ptr)->lock & 1) +#define IABS(x) ((x) > 0 ? (x) : -(x)) + +#define RWLOCK_READERS(rwlock_ptr) rwlock_readers(rwlock_ptr) +extern inline int rwlock_readers(rwlock_t *rwlock_ptr) +{ + int tmp = (int) ((inst_rwlock_t *)rwlock_ptr)->lock; + /* readers subtract 2, so we have to: */ + /* - andnot off a possible writer (bit 0) */ + /* - get the absolute value */ + /* - divide by 2 (right shift by one) */ + /* to find the number of readers */ + if (tmp == 0) return(0); + else return(IABS(tmp & ~1)>>1); +} + +#endif /* _ALPHA_LOCKMETER_H */ diff -puN include/asm-alpha/spinlock.h~lockmeter include/asm-alpha/spinlock.h --- 25/include/asm-alpha/spinlock.h~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/include/asm-alpha/spinlock.h Fri May 14 17:40:32 2004 @@ -6,6 +6,10 @@ #include #include +#ifdef CONFIG_LOCKMETER +#undef DEBUG_SPINLOCK +#undef DEBUG_RWLOCK +#endif /* * Simple spin lock operations. There are two variants, one clears IRQ's @@ -96,9 +100,18 @@ static inline int _raw_spin_trylock(spin typedef struct { volatile int write_lock:1, read_counter:31; +#ifdef CONFIG_LOCKMETER + /* required for LOCKMETER since all bits in lock are used */ + /* need this storage for CPU and lock INDEX ............. */ + unsigned magic; +#endif } /*__attribute__((aligned(32)))*/ rwlock_t; +#ifdef CONFIG_LOCKMETER +#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, 0 } +#else #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 } +#endif #define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) #define rwlock_is_locked(x) (*(volatile int *)(x) != 0) @@ -170,4 +183,41 @@ static inline void _raw_read_unlock(rwlo : "m" (*lock) : "memory"); } +#ifdef CONFIG_LOCKMETER +static inline int _raw_write_trylock(rwlock_t *lock) +{ + long temp,result; + + __asm__ __volatile__( + " ldl_l %1,%0\n" + " mov $31,%2\n" + " bne %1,1f\n" + " or $31,1,%2\n" + " stl_c %2,%0\n" + "1: mb\n" + : "=m" (*(volatile int *)lock), "=&r" (temp), "=&r" (result) + : "m" (*(volatile int *)lock) + ); + + return (result); +} + +static inline int _raw_read_trylock(rwlock_t *lock) +{ + unsigned long temp,result; + + __asm__ __volatile__( + " ldl_l %1,%0\n" + " mov $31,%2\n" + " blbs %1,1f\n" + " subl %1,2,%2\n" + " stl_c %2,%0\n" + "1: mb\n" + : "=m" (*(volatile int *)lock), "=&r" (temp), "=&r" (result) + : "m" (*(volatile int *)lock) + ); + return (result); +} +#endif /* CONFIG_LOCKMETER */ + #endif /* _ALPHA_SPINLOCK_H */ diff -puN /dev/null include/asm-i386/lockmeter.h --- /dev/null Thu Apr 11 07:25:15 2002 +++ 25-akpm/include/asm-i386/lockmeter.h Fri May 14 17:40:32 2004 @@ -0,0 +1,115 @@ +/* + * Copyright (C) 1999,2000 Silicon Graphics, Inc. + * + * Written by John Hawkes (hawkes@sgi.com) + * Based on klstat.h by Jack Steiner (steiner@sgi.com) + * + * Modified by Ray Bryant (raybry@us.ibm.com) + * Changes Copyright (C) 2000 IBM, Inc. + * Added save of index in spinlock_t to improve efficiency + * of "hold" time reporting for spinlocks. + * Added support for hold time statistics for read and write + * locks. + * Moved machine dependent code here from include/lockmeter.h. + * + */ + +#ifndef _I386_LOCKMETER_H +#define _I386_LOCKMETER_H + +#include +#include + +#include + +#ifdef __KERNEL__ +extern unsigned long cpu_khz; +#define CPU_CYCLE_FREQUENCY (cpu_khz * 1000) +#else +#define CPU_CYCLE_FREQUENCY 450000000 +#endif + +#define THIS_CPU_NUMBER smp_processor_id() + +/* + * macros to cache and retrieve an index value inside of a spin lock + * these macros assume that there are less than 65536 simultaneous + * (read mode) holders of a rwlock. Not normally a problem!! + * we also assume that the hash table has less than 65535 entries. + */ +/* + * instrumented spinlock structure -- never used to allocate storage + * only used in macros below to overlay a spinlock_t + */ +typedef struct inst_spinlock_s { + /* remember, Intel is little endian */ + unsigned short lock; + unsigned short index; +} inst_spinlock_t; +#define PUT_INDEX(lock_ptr,indexv) ((inst_spinlock_t *)(lock_ptr))->index = indexv +#define GET_INDEX(lock_ptr) ((inst_spinlock_t *)(lock_ptr))->index + +/* + * macros to cache and retrieve an index value in a read/write lock + * as well as the cpu where a reader busy period started + * we use the 2nd word (the debug word) for this, so require the + * debug word to be present + */ +/* + * instrumented rwlock structure -- never used to allocate storage + * only used in macros below to overlay a rwlock_t + */ +typedef struct inst_rwlock_s { + volatile int lock; + unsigned short index; + unsigned short cpu; +} inst_rwlock_t; +#define PUT_RWINDEX(rwlock_ptr,indexv) ((inst_rwlock_t *)(rwlock_ptr))->index = indexv +#define GET_RWINDEX(rwlock_ptr) ((inst_rwlock_t *)(rwlock_ptr))->index +#define PUT_RW_CPU(rwlock_ptr,cpuv) ((inst_rwlock_t *)(rwlock_ptr))->cpu = cpuv +#define GET_RW_CPU(rwlock_ptr) ((inst_rwlock_t *)(rwlock_ptr))->cpu + +/* + * return the number of readers for a rwlock_t + */ +#define RWLOCK_READERS(rwlock_ptr) rwlock_readers(rwlock_ptr) + +extern inline int rwlock_readers(rwlock_t *rwlock_ptr) +{ + int tmp = (int) rwlock_ptr->lock; + /* read and write lock attempts may cause the lock value to temporarily */ + /* be negative. Until it is >= 0 we know nothing (i. e. can't tell if */ + /* is -1 because it was write locked and somebody tried to read lock it */ + /* or if it is -1 because it was read locked and somebody tried to write*/ + /* lock it. ........................................................... */ + do { + tmp = (int) rwlock_ptr->lock; + } while (tmp < 0); + if (tmp == 0) return(0); + else return(RW_LOCK_BIAS-tmp); +} + +/* + * return true if rwlock is write locked + * (note that other lock attempts can cause the lock value to be negative) + */ +#define RWLOCK_IS_WRITE_LOCKED(rwlock_ptr) ((rwlock_ptr)->lock <= 0) +#define IABS(x) ((x) > 0 ? (x) : -(x)) +#define RWLOCK_IS_READ_LOCKED(rwlock_ptr) ((IABS((rwlock_ptr)->lock) % RW_LOCK_BIAS) != 0) + +/* this is a lot of typing just to get gcc to emit "rdtsc" */ +static inline long long get_cycles64 (void) +{ + union longlong_u { + long long intlong; + struct intint_s { + uint32_t eax; + uint32_t edx; + } intint; + } longlong; + + rdtsc(longlong.intint.eax,longlong.intint.edx); + return longlong.intlong; +} + +#endif /* _I386_LOCKMETER_H */ diff -puN include/asm-i386/spinlock.h~lockmeter include/asm-i386/spinlock.h --- 25/include/asm-i386/spinlock.h~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/include/asm-i386/spinlock.h Fri May 14 17:40:32 2004 @@ -201,6 +201,11 @@ here: */ typedef struct { volatile unsigned int lock; +#ifdef CONFIG_LOCKMETER + /* required for LOCKMETER since all bits in lock are used */ + /* and we need this storage for CPU and lock INDEX */ + unsigned lockmeter_magic; +#endif #ifdef CONFIG_DEBUG_SPINLOCK unsigned magic; #endif @@ -208,11 +213,19 @@ typedef struct { #define RWLOCK_MAGIC 0xdeaf1eed +#ifdef CONFIG_LOCKMETER +#ifdef CONFIG_DEBUG_SPINLOCK +#define RWLOCK_MAGIC_INIT , 0, RWLOCK_MAGIC +#else +#define RWLOCK_MAGIC_INIT , 0 +#endif +#else /* !CONFIG_LOCKMETER */ #ifdef CONFIG_DEBUG_SPINLOCK #define RWLOCK_MAGIC_INIT , RWLOCK_MAGIC #else #define RWLOCK_MAGIC_INIT /* */ #endif +#endif /* !CONFIG_LOCKMETER */ #define RW_LOCK_UNLOCKED (rwlock_t) { RW_LOCK_BIAS RWLOCK_MAGIC_INIT } @@ -259,4 +272,60 @@ static inline int _raw_write_trylock(rwl return 0; } +#ifdef CONFIG_LOCKMETER +static inline int _raw_read_trylock(rwlock_t *lock) +{ +/* FIXME -- replace with assembler */ + atomic_t *count = (atomic_t *)lock; + atomic_dec(count); + if (count->counter > 0) + return 1; + atomic_inc(count); + return 0; +} +#endif + +#if defined(CONFIG_LOCKMETER) && defined(CONFIG_HAVE_DEC_LOCK) +extern void _metered_spin_lock (spinlock_t *lock); +extern void _metered_spin_unlock(spinlock_t *lock); + +/* + * Matches what is in arch/i386/lib/dec_and_lock.c, except this one is + * "static inline" so that the spin_lock(), if actually invoked, is charged + * against the real caller, not against the catch-all atomic_dec_and_lock + */ +static inline int atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) +{ + int counter; + int newcount; + +repeat: + counter = atomic_read(atomic); + newcount = counter-1; + + if (!newcount) + goto slow_path; + + asm volatile("lock; cmpxchgl %1,%2" + :"=a" (newcount) + :"r" (newcount), "m" (atomic->counter), "0" (counter)); + + /* If the above failed, "eax" will have changed */ + if (newcount != counter) + goto repeat; + return 0; + +slow_path: + preempt_disable(); + _metered_spin_lock(lock); + if (atomic_dec_and_test(atomic)) + return 1; + _metered_spin_unlock(lock); + preempt_enable(); + return 0; +} + +#define ATOMIC_DEC_AND_LOCK +#endif + #endif /* __ASM_SPINLOCK_H */ diff -puN /dev/null include/asm-ia64/lockmeter.h --- /dev/null Thu Apr 11 07:25:15 2002 +++ 25-akpm/include/asm-ia64/lockmeter.h Fri May 14 17:40:32 2004 @@ -0,0 +1,72 @@ +/* + * Copyright (C) 1999,2000 Silicon Graphics, Inc. + * + * Written by John Hawkes (hawkes@sgi.com) + * Based on klstat.h by Jack Steiner (steiner@sgi.com) + */ + +#ifndef _IA64_LOCKMETER_H +#define _IA64_LOCKMETER_H + +#ifdef local_cpu_data +#define CPU_CYCLE_FREQUENCY local_cpu_data->itc_freq +#else +#define CPU_CYCLE_FREQUENCY my_cpu_data.itc_freq +#endif +#define get_cycles64() get_cycles() + +#define THIS_CPU_NUMBER smp_processor_id() + +/* + * macros to cache and retrieve an index value inside of a lock + * these macros assume that there are less than 65536 simultaneous + * (read mode) holders of a rwlock. + * we also assume that the hash table has less than 32767 entries. + */ +/* + * instrumented spinlock structure -- never used to allocate storage + * only used in macros below to overlay a spinlock_t + */ +typedef struct inst_spinlock_s { + /* remember, Intel is little endian */ + volatile unsigned short lock; + volatile unsigned short index; +} inst_spinlock_t; +#define PUT_INDEX(lock_ptr,indexv) ((inst_spinlock_t *)(lock_ptr))->index = indexv +#define GET_INDEX(lock_ptr) ((inst_spinlock_t *)(lock_ptr))->index + +/* + * macros to cache and retrieve an index value in a read/write lock + * as well as the cpu where a reader busy period started + * we use the 2nd word (the debug word) for this, so require the + * debug word to be present + */ +/* + * instrumented rwlock structure -- never used to allocate storage + * only used in macros below to overlay a rwlock_t + */ +typedef struct inst_rwlock_s { + volatile int read_counter:31; + volatile int write_lock:1; + volatile unsigned short index; + volatile unsigned short cpu; +} inst_rwlock_t; +#define PUT_RWINDEX(rwlock_ptr,indexv) ((inst_rwlock_t *)(rwlock_ptr))->index = indexv +#define GET_RWINDEX(rwlock_ptr) ((inst_rwlock_t *)(rwlock_ptr))->index +#define PUT_RW_CPU(rwlock_ptr,cpuv) ((inst_rwlock_t *)(rwlock_ptr))->cpu = cpuv +#define GET_RW_CPU(rwlock_ptr) ((inst_rwlock_t *)(rwlock_ptr))->cpu + +/* + * return the number of readers for a rwlock_t + */ +#define RWLOCK_READERS(rwlock_ptr) ((rwlock_ptr)->read_counter) + +/* + * return true if rwlock is write locked + * (note that other lock attempts can cause the lock value to be negative) + */ +#define RWLOCK_IS_WRITE_LOCKED(rwlock_ptr) ((rwlock_ptr)->write_lock) +#define RWLOCK_IS_READ_LOCKED(rwlock_ptr) ((rwlock_ptr)->read_counter) + +#endif /* _IA64_LOCKMETER_H */ + diff -puN include/asm-ia64/spinlock.h~lockmeter include/asm-ia64/spinlock.h --- 25/include/asm-ia64/spinlock.h~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/include/asm-ia64/spinlock.h Fri May 14 17:40:32 2004 @@ -116,8 +116,18 @@ do { \ typedef struct { volatile int read_counter : 31; volatile int write_lock : 1; +#ifdef CONFIG_LOCKMETER + /* required for LOCKMETER since all bits in lock are used */ + /* and we need this storage for CPU and lock INDEX */ + unsigned lockmeter_magic; +#endif } rwlock_t; + +#ifdef CONFIG_LOCKMETER +#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, 0 } +#else #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 } +#endif #define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) #define rwlock_is_locked(x) (*(volatile int *) (x) != 0) @@ -133,6 +143,48 @@ do { \ } \ } while (0) +#ifdef CONFIG_LOCKMETER +/* + * HACK: This works, but still have a timing window that affects performance: + * we see that no one owns the Write lock, then someone * else grabs for Write + * lock before we do a read_lock(). + * This means that on rare occasions our read_lock() will stall and spin-wait + * until we acquire for Read, instead of simply returning a trylock failure. + */ +static inline int _raw_read_trylock(rwlock_t *rw) +{ + if (rw->write_lock) { + return 0; + } else { + _raw_read_lock(rw); + return 1; + } +} + +static inline int _raw_write_trylock(rwlock_t *rw) +{ + if (!(rw->write_lock)) { + /* isn't currently write-locked... that looks promising... */ + if (test_and_set_bit(31, rw) == 0) { + /* now it is write-locked by me... */ + if (rw->read_counter) { + /* really read-locked, so release write-lock and fail */ + clear_bit(31, rw); + } else { + /* we've the the write-lock, no read-lockers... success! */ + barrier(); + return 1; + } + + } + } + + /* falls through ... fails to write-lock */ + barrier(); + return 0; +} +#endif + #define _raw_read_unlock(rw) \ do { \ rwlock_t *__read_lock_ptr = (rw); \ @@ -196,4 +248,25 @@ do { \ clear_bit(31, (x)); \ }) +#ifdef CONFIG_LOCKMETER +extern void _metered_spin_lock (spinlock_t *lock); +extern void _metered_spin_unlock(spinlock_t *lock); + +/* + * Use a less efficient, and inline, atomic_dec_and_lock() if lockmetering + * so we can see the callerPC of who is actually doing the spin_lock(). + * Otherwise, all we see is the generic rollup of all locks done by + * atomic_dec_and_lock(). + */ +static inline int atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) +{ + _metered_spin_lock(lock); + if (atomic_dec_and_test(atomic)) + return 1; + _metered_spin_unlock(lock); + return 0; +} +#define ATOMIC_DEC_AND_LOCK +#endif + #endif /* _ASM_IA64_SPINLOCK_H */ diff -puN /dev/null include/asm-mips/lockmeter.h --- /dev/null Thu Apr 11 07:25:15 2002 +++ 25-akpm/include/asm-mips/lockmeter.h Fri May 14 17:40:32 2004 @@ -0,0 +1,126 @@ +/* + * Copyright (C) 1999,2000 Silicon Graphics, Inc. + * + * Written by John Hawkes (hawkes@sgi.com) + * Based on klstat.h by Jack Steiner (steiner@sgi.com) + * Ported to mips32 for Asita Technologies + * by D.J. Barrow ( dj.barrow@asitatechnologies.com ) + */ +#ifndef _ASM_LOCKMETER_H +#define _ASM_LOCKMETER_H + +/* do_gettimeoffset is a function pointer on mips */ +/* & it is not included by */ +#include +#include +#include + +#define SPINLOCK_MAGIC_INIT /* */ + +#define CPU_CYCLE_FREQUENCY get_cpu_cycle_frequency() + +#define THIS_CPU_NUMBER smp_processor_id() + +static uint32_t cpu_cycle_frequency = 0; + +static uint32_t get_cpu_cycle_frequency(void) +{ + /* a total hack, slow and invasive, but ... it works */ + int sec; + uint32_t start_cycles; + struct timeval tv; + + if (cpu_cycle_frequency == 0) { /* uninitialized */ + do_gettimeofday(&tv); + sec = tv.tv_sec; /* set up to catch the tv_sec rollover */ + while (sec == tv.tv_sec) { do_gettimeofday(&tv); } + sec = tv.tv_sec; /* rolled over to a new sec value */ + start_cycles = get_cycles(); + while (sec == tv.tv_sec) { do_gettimeofday(&tv); } + cpu_cycle_frequency = get_cycles() - start_cycles; + } + + return cpu_cycle_frequency; +} + +extern struct timeval xtime; + +static uint64_t get_cycles64(void) +{ + static uint64_t last_get_cycles64 = 0; + uint64_t ret; + unsigned long sec; + unsigned long usec, usec_offset; + +again: + sec = xtime.tv_sec; + usec = xtime.tv_usec; + usec_offset = do_gettimeoffset(); + if ((xtime.tv_sec != sec) || + (xtime.tv_usec != usec)|| + (usec_offset >= 20000)) + goto again; + + ret = ((uint64_t)(usec + usec_offset) * cpu_cycle_frequency); + /* We can't do a normal 64 bit division on mips without libgcc.a */ + do_div(ret,1000000); + ret += ((uint64_t)sec * cpu_cycle_frequency); + + /* XXX why does time go backwards? do_gettimeoffset? general time adj? */ + if (ret <= last_get_cycles64) + ret = last_get_cycles64+1; + last_get_cycles64 = ret; + + return ret; +} + +/* + * macros to cache and retrieve an index value inside of a lock + * these macros assume that there are less than 65536 simultaneous + * (read mode) holders of a rwlock. + * we also assume that the hash table has less than 32767 entries. + * the high order bit is used for write locking a rw_lock + */ +#define INDEX_MASK 0x7FFF0000 +#define READERS_MASK 0x0000FFFF +#define INDEX_SHIFT 16 +#define PUT_INDEX(lockp,index) \ + lockp->lock = (((lockp->lock) & ~INDEX_MASK) | (index) << INDEX_SHIFT) +#define GET_INDEX(lockp) \ + (((lockp->lock) & INDEX_MASK) >> INDEX_SHIFT) + +/* + * macros to cache and retrieve an index value in a read/write lock + * as well as the cpu where a reader busy period started + * we use the 2nd word (the debug word) for this, so require the + * debug word to be present + */ +/* + * instrumented rwlock structure -- never used to allocate storage + * only used in macros below to overlay a rwlock_t + */ +typedef struct inst_rwlock_s { + volatile int lock; + unsigned short index; + unsigned short cpu; +} inst_rwlock_t; +#define PUT_RWINDEX(rwlock_ptr,indexv) ((inst_rwlock_t *)(rwlock_ptr))->index = indexv +#define GET_RWINDEX(rwlock_ptr) ((inst_rwlock_t *)(rwlock_ptr))->index +#define PUT_RW_CPU(rwlock_ptr,cpuv) ((inst_rwlock_t *)(rwlock_ptr))->cpu = cpuv +#define GET_RW_CPU(rwlock_ptr) ((inst_rwlock_t *)(rwlock_ptr))->cpu + +/* + * return the number of readers for a rwlock_t + */ +#define RWLOCK_READERS(rwlock_ptr) rwlock_readers(rwlock_ptr) + +extern inline int rwlock_readers(rwlock_t *rwlock_ptr) +{ + int tmp = (int) rwlock_ptr->lock; + return (tmp >= 0) ? tmp : 0; +} + +#define RWLOCK_IS_WRITE_LOCKED(rwlock_ptr) ((rwlock_ptr)->lock < 0) +#define RWLOCK_IS_READ_LOCKED(rwlock_ptr) ((rwlock_ptr)->lock > 0) + +#endif /* _ASM_LOCKMETER_H */ diff -puN include/asm-mips/spinlock.h~lockmeter include/asm-mips/spinlock.h --- 25/include/asm-mips/spinlock.h~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/include/asm-mips/spinlock.h Fri May 14 17:40:32 2004 @@ -92,9 +92,18 @@ static inline unsigned int _raw_spin_try typedef struct { volatile unsigned int lock; +#ifdef CONFIG_LOCKMETER + /* required for LOCKMETER since all bits in lock are used */ + /* and we need this storage for CPU and lock INDEX */ + unsigned lockmeter_magic; +#endif } rwlock_t; +#ifdef CONFIG_LOCKMETER +#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 } +#else #define RW_LOCK_UNLOCKED (rwlock_t) { 0 } +#endif #define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) diff -puN /dev/null include/asm-sparc64/lockmeter.h --- /dev/null Thu Apr 11 07:25:15 2002 +++ 25-akpm/include/asm-sparc64/lockmeter.h Fri May 14 17:40:32 2004 @@ -0,0 +1,45 @@ +/* + * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com) + * Copyright (C) 2003 David S. Miller (davem@redhat.com) + */ + +#ifndef _SPARC64_LOCKMETER_H +#define _SPARC64_LOCKMETER_H + +#include +#include +#include +#include + +/* Actually, this is not the CPU frequency by the system tick + * frequency which is good enough for lock metering. + */ +#define CPU_CYCLE_FREQUENCY (timer_tick_offset * HZ) +#define THIS_CPU_NUMBER smp_processor_id() + +#define PUT_INDEX(lock_ptr,indexv) (lock_ptr)->index = (indexv) +#define GET_INDEX(lock_ptr) (lock_ptr)->index + +#define PUT_RWINDEX(rwlock_ptr,indexv) (rwlock_ptr)->index = (indexv) +#define GET_RWINDEX(rwlock_ptr) (rwlock_ptr)->index +#define PUT_RW_CPU(rwlock_ptr,cpuv) (rwlock_ptr)->cpu = (cpuv) +#define GET_RW_CPU(rwlock_ptr) (rwlock_ptr)->cpu + +#define RWLOCK_READERS(rwlock_ptr) rwlock_readers(rwlock_ptr) + +extern inline int rwlock_readers(rwlock_t *rwlock_ptr) +{ + signed int tmp = rwlock_ptr->lock; + + if (tmp > 0) + return tmp; + else + return 0; +} + +#define RWLOCK_IS_WRITE_LOCKED(rwlock_ptr) ((signed int)((rwlock_ptr)->lock) < 0) +#define RWLOCK_IS_READ_LOCKED(rwlock_ptr) ((signed int)((rwlock_ptr)->lock) > 0) + +#define get_cycles64() get_cycles() + +#endif /* _SPARC64_LOCKMETER_H */ diff -puN include/asm-sparc64/spinlock.h~lockmeter include/asm-sparc64/spinlock.h --- 25/include/asm-sparc64/spinlock.h~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/include/asm-sparc64/spinlock.h Fri May 14 17:40:32 2004 @@ -31,15 +31,23 @@ #ifndef CONFIG_DEBUG_SPINLOCK -typedef unsigned char spinlock_t; -#define SPIN_LOCK_UNLOCKED 0 +typedef struct { + unsigned char lock; + unsigned int index; +} spinlock_t; -#define spin_lock_init(lock) (*((unsigned char *)(lock)) = 0) -#define spin_is_locked(lock) (*((volatile unsigned char *)(lock)) != 0) +#ifdef CONFIG_LOCKMETER +#define SPIN_LOCK_UNLOCKED (spinlock_t) {0, 0} +#else +#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } +#endif + +#define spin_lock_init(__lock) do { *(__lock) = SPIN_LOCK_UNLOCKED; } while(0) +#define spin_is_locked(__lock) (*((volatile unsigned char *)(&((__lock)->lock))) != 0) -#define spin_unlock_wait(lock) \ +#define spin_unlock_wait(__lock) \ do { membar("#LoadLoad"); \ -} while(*((volatile unsigned char *)lock)) +} while(*((volatile unsigned char *)(&(((spinlock_t *)__lock)->lock)))) static __inline__ void _raw_spin_lock(spinlock_t *lock) { @@ -112,17 +120,31 @@ extern int _spin_trylock (spinlock_t *lo #ifndef CONFIG_DEBUG_SPINLOCK -typedef unsigned int rwlock_t; -#define RW_LOCK_UNLOCKED 0 -#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0) -#define rwlock_is_locked(x) (*(x) != RW_LOCK_UNLOCKED) +#ifdef CONFIG_LOCKMETER +typedef struct { + unsigned int lock; + unsigned int index; + unsigned int cpu; +} rwlock_t; +#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, 0xff } +#else +typedef struct { + unsigned int lock; +} rwlock_t; +#define RW_LOCK_UNLOCKED (rwlock_t) { 0 } +#endif + +#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0) +#define rwlock_is_locked(x) ((x)->lock != 0) +extern int __read_trylock(rwlock_t *); extern void __read_lock(rwlock_t *); extern void __read_unlock(rwlock_t *); extern void __write_lock(rwlock_t *); extern void __write_unlock(rwlock_t *); extern int __write_trylock(rwlock_t *); +#define _raw_read_trylock(p) __read_trylock(p) #define _raw_read_lock(p) __read_lock(p) #define _raw_read_unlock(p) __read_unlock(p) #define _raw_write_lock(p) __write_lock(p) diff -puN /dev/null include/linux/lockmeter.h --- /dev/null Thu Apr 11 07:25:15 2002 +++ 25-akpm/include/linux/lockmeter.h Fri May 14 17:40:32 2004 @@ -0,0 +1,320 @@ +/* + * Copyright (C) 1999-2002 Silicon Graphics, Inc. + * + * Written by John Hawkes (hawkes@sgi.com) + * Based on klstat.h by Jack Steiner (steiner@sgi.com) + * + * Modified by Ray Bryant (raybry@us.ibm.com) Feb-Apr 2000 + * Changes Copyright (C) 2000 IBM, Inc. + * Added save of index in spinlock_t to improve efficiency + * of "hold" time reporting for spinlocks + * Added support for hold time statistics for read and write + * locks. + * Moved machine dependent code to include/asm/lockmeter.h. + * + */ + +#ifndef _LINUX_LOCKMETER_H +#define _LINUX_LOCKMETER_H + + +/*--------------------------------------------------- + * architecture-independent lockmeter.h + *-------------------------------------------------*/ + +/* + * raybry -- version 2: added efficient hold time statistics + * requires lstat recompile, so flagged as new version + * raybry -- version 3: added global reader lock data + * hawkes -- version 4: removed some unnecessary fields to simplify mips64 port + */ +#define LSTAT_VERSION 5 + +int lstat_update(void*, void*, int); +int lstat_update_time(void*, void*, int, uint32_t); + +/* + * Currently, the mips64 and sparc64 kernels talk to a 32-bit lockstat, so we + * need to force compatibility in the inter-communication data structure. + */ + +#if defined(CONFIG_MIPS32_COMPAT) +#define TIME_T uint32_t +#elif defined(CONFIG_SPARC) || defined(CONFIG_SPARC64) +#define TIME_T uint64_t +#else +#define TIME_T time_t +#endif + +#if defined(__KERNEL__) || (!defined(CONFIG_MIPS32_COMPAT) && !defined(CONFIG_SPARC) && !defined(CONFIG_SPARC64)) || (_MIPS_SZLONG==32) +#define POINTER void * +#else +#define POINTER int64_t +#endif + +/* + * Values for the "action" parameter passed to lstat_update. + * ZZZ - do we want a try-success status here??? + */ +#define LSTAT_ACT_NO_WAIT 0 +#define LSTAT_ACT_SPIN 1 +#define LSTAT_ACT_REJECT 2 +#define LSTAT_ACT_WW_SPIN 3 +#define LSTAT_ACT_SLEPT 4 /* UNUSED */ + +#define LSTAT_ACT_MAX_VALUES 4 /* NOTE: Increase to 5 if use ACT_SLEPT */ + +/* + * Special values for the low 2 bits of an RA passed to + * lstat_update. + */ +/* we use these values to figure out what kind of lock data */ +/* is stored in the statistics table entry at index ....... */ +#define LSTAT_RA_SPIN 0 /* spin lock data */ +#define LSTAT_RA_READ 1 /* read lock statistics */ +#define LSTAT_RA_SEMA 2 /* RESERVED */ +#define LSTAT_RA_WRITE 3 /* write lock statistics*/ + +#define LSTAT_RA(n) \ + ((void*)( ((unsigned long)__builtin_return_address(0) & ~3) | n) ) + +/* + * Constants used for lock addresses in the lstat_directory + * to indicate special values of the lock address. + */ +#define LSTAT_MULTI_LOCK_ADDRESS NULL + +/* + * Maximum size of the lockstats tables. Increase this value + * if its not big enough. (Nothing bad happens if its not + * big enough although some locks will not be monitored.) + * We record overflows of this quantity in lstat_control.dir_overflows + * + * Note: The max value here must fit into the field set + * and obtained by the macro's PUT_INDEX() and GET_INDEX(). + * This value depends on how many bits are available in the + * lock word in the particular machine implementation we are on. + */ +#define LSTAT_MAX_STAT_INDEX 2000 + +/* + * Size and mask for the hash table into the directory. + */ +#define LSTAT_HASH_TABLE_SIZE 4096 /* must be 2**N */ +#define LSTAT_HASH_TABLE_MASK (LSTAT_HASH_TABLE_SIZE-1) + +#define DIRHASH(ra) ((unsigned long)(ra)>>2 & LSTAT_HASH_TABLE_MASK) + +/* + * This defines an entry in the lockstat directory. It contains + * information about a lock being monitored. + * A directory entry only contains the lock identification - + * counts on usage of the lock are kept elsewhere in a per-cpu + * data structure to minimize cache line pinging. + */ +typedef struct { + POINTER caller_ra; /* RA of code that set lock */ + POINTER lock_ptr; /* lock address */ + ushort next_stat_index; /* Used to link multiple locks that have the same hash table value */ +} lstat_directory_entry_t; + +/* + * A multi-dimensioned array used to contain counts for lock accesses. + * The array is 3-dimensional: + * - CPU number. Keep from thrashing cache lines between CPUs + * - Directory entry index. Identifies the lock + * - Action. Indicates what kind of contention occurred on an + * access to the lock. + * + * The index of an entry in the directory is the same as the 2nd index + * of the entry in the counts array. + */ +/* + * This table contains data for spin_locks, write locks, and read locks + * Not all data is used for all cases. In particular, the hold time + * information is not stored here for read locks since that is a global + * (e. g. cannot be separated out by return address) quantity. + * See the lstat_read_lock_counts_t structure for the global read lock + * hold time. + */ +typedef struct { + uint64_t cum_wait_ticks; /* sum of wait times */ + /* for write locks, sum of time a */ + /* writer is waiting for a reader */ + int64_t cum_hold_ticks; /* cumulative sum of holds */ + /* not used for read mode locks */ + /* must be signed. ............... */ + uint32_t max_wait_ticks; /* max waiting time */ + uint32_t max_hold_ticks; /* max holding time */ + uint64_t cum_wait_ww_ticks; /* sum times writer waits on writer*/ + uint32_t max_wait_ww_ticks; /* max wait time writer vs writer */ + /* prev 2 only used for write locks*/ + uint32_t acquire_time; /* time lock acquired this CPU */ + uint32_t count[LSTAT_ACT_MAX_VALUES]; +} lstat_lock_counts_t; + +typedef lstat_lock_counts_t lstat_cpu_counts_t[LSTAT_MAX_STAT_INDEX]; + +/* + * User request to: + * - turn statistic collection on/off, or to reset + */ +#define LSTAT_OFF 0 +#define LSTAT_ON 1 +#define LSTAT_RESET 2 +#define LSTAT_RELEASE 3 + +#define LSTAT_MAX_READ_LOCK_INDEX 1000 +typedef struct { + POINTER lock_ptr; /* address of lock for output stats */ + uint32_t read_lock_count; + int64_t cum_hold_ticks; /* sum of read lock hold times over */ + /* all callers. ....................*/ + uint32_t write_index; /* last write lock hash table index */ + uint32_t busy_periods; /* count of busy periods ended this */ + uint64_t start_busy; /* time this busy period started. ..*/ + uint64_t busy_ticks; /* sum of busy periods this lock. ..*/ + uint64_t max_busy; /* longest busy period for this lock*/ + uint32_t max_readers; /* maximum number of readers ...... */ +#ifdef USER_MODE_TESTING + rwlock_t entry_lock; /* lock for this read lock entry... */ + /* avoid having more than one rdr at*/ + /* needed for user space testing... */ + /* not needed for kernel 'cause it */ + /* is non-preemptive. ............. */ +#endif +} lstat_read_lock_counts_t; +typedef lstat_read_lock_counts_t lstat_read_lock_cpu_counts_t[LSTAT_MAX_READ_LOCK_INDEX]; + +#if defined(__KERNEL__) || defined(USER_MODE_TESTING) + +#ifndef USER_MODE_TESTING +#include +#else +#include "asm_newlockmeter.h" +#endif + +/* + * Size and mask for the hash table into the directory. + */ +#define LSTAT_HASH_TABLE_SIZE 4096 /* must be 2**N */ +#define LSTAT_HASH_TABLE_MASK (LSTAT_HASH_TABLE_SIZE-1) + +#define DIRHASH(ra) ((unsigned long)(ra)>>2 & LSTAT_HASH_TABLE_MASK) + +/* + * This version eliminates the per processor lock stack. What we do is to + * store the index of the lock hash structure in unused bits in the lock + * itself. Then on unlock we can find the statistics record without doing + * any additional hash or lock stack lookup. This works for spin_locks. + * Hold time reporting is now basically as cheap as wait time reporting + * so we ignore the difference between LSTAT_ON_HOLD and LSTAT_ON_WAIT + * as in version 1.1.* of lockmeter. + * + * For rw_locks, we store the index of a global reader stats structure in + * the lock and the writer index is stored in the latter structure. + * For read mode locks we hash at the time of the lock to find an entry + * in the directory for reader wait time and the like. + * At unlock time for read mode locks, we update just the global structure + * so we don't need to know the reader directory index value at unlock time. + * + */ + +/* + * Protocol to change lstat_control.state + * This is complicated because we don't want the cum_hold_time for + * a rw_lock to be decremented in _read_lock_ without making sure it + * is incremented in _read_lock_ and vice versa. So here is the + * way we change the state of lstat_control.state: + * I. To Turn Statistics On + * After allocating storage, set lstat_control.state non-zero. + * This works because we don't start updating statistics for in use + * locks until the reader lock count goes to zero. + * II. To Turn Statistics Off: + * (0) Disable interrupts on this CPU + * (1) Seize the lstat_control.directory_lock + * (2) Obtain the current value of lstat_control.next_free_read_lock_index + * (3) Store a zero in lstat_control.state. + * (4) Release the lstat_control.directory_lock + * (5) For each lock in the read lock list up to the saved value + * (well, -1) of the next_free_read_lock_index, do the following: + * (a) Check validity of the stored lock address + * by making sure that the word at the saved addr + * has an index that matches this entry. If not + * valid, then skip this entry. + * (b) If there is a write lock already set on this lock, + * skip to (d) below. + * (c) Set a non-metered write lock on the lock + * (d) set the cached INDEX in the lock to zero + * (e) Release the non-metered write lock. + * (6) Re-enable interrupts + * + * These rules ensure that a read lock will not have its statistics + * partially updated even though the global lock recording state has + * changed. See put_lockmeter_info() for implementation. + * + * The reason for (b) is that there may be write locks set on the + * syscall path to put_lockmeter_info() from user space. If we do + * not do this check, then we can deadlock. A similar problem would + * occur if the lock was read locked by the current CPU. At the + * moment this does not appear to happen. + */ + +/* + * Main control structure for lockstat. Used to turn statistics on/off + * and to maintain directory info. + */ +typedef struct { + int state; + spinlock_t control_lock; /* used to serialize turning statistics on/off */ + spinlock_t directory_lock; /* for serialize adding entries to directory */ + volatile int next_free_dir_index;/* next free entry in the directory */ + /* FIXME not all of these fields are used / needed .............. */ + /* the following fields represent data since */ + /* first "lstat on" or most recent "lstat reset" */ + TIME_T first_started_time; /* time when measurement first enabled */ + TIME_T started_time; /* time when measurement last started */ + TIME_T ending_time; /* time when measurement last disabled */ + uint64_t started_cycles64; /* cycles when measurement last started */ + uint64_t ending_cycles64; /* cycles when measurement last disabled */ + uint64_t enabled_cycles64; /* total cycles with measurement enabled */ + int intervals; /* number of measurement intervals recorded */ + /* i. e. number of times did lstat on;lstat off */ + lstat_directory_entry_t *dir; /* directory */ + int dir_overflow; /* count of times ran out of space in directory */ + int rwlock_overflow; /* count of times we couldn't allocate a rw block*/ + ushort *hashtab; /* hash table for quick dir scans */ + lstat_cpu_counts_t *counts[NR_CPUS]; /* Array of pointers to per-cpu stats */ + int next_free_read_lock_index; /* next rwlock reader (global) stats block */ + lstat_read_lock_cpu_counts_t *read_lock_counts[NR_CPUS]; /* per cpu read lock stats */ +} lstat_control_t; + +#endif /* defined(__KERNEL__) || defined(USER_MODE_TESTING) */ + +typedef struct { + short lstat_version; /* version of the data */ + short state; /* the current state is returned */ + int maxcpus; /* Number of cpus present */ + int next_free_dir_index; /* index of the next free directory entry */ + TIME_T first_started_time; /* when measurement enabled for first time */ + TIME_T started_time; /* time in secs since 1969 when stats last turned on */ + TIME_T ending_time; /* time in secs since 1969 when stats last turned off */ + uint32_t cycleval; /* cycles per second */ +#ifdef notyet + void *kernel_magic_addr; /* address of kernel_magic */ + void *kernel_end_addr; /* contents of kernel magic (points to "end") */ +#endif + int next_free_read_lock_index; /* index of next (global) read lock stats struct */ + uint64_t started_cycles64; /* cycles when measurement last started */ + uint64_t ending_cycles64; /* cycles when stats last turned off */ + uint64_t enabled_cycles64; /* total cycles with measurement enabled */ + int intervals; /* number of measurement intervals recorded */ + /* i.e. number of times we did lstat on;lstat off*/ + int dir_overflow; /* number of times we wanted more space in directory */ + int rwlock_overflow; /* # of times we wanted more space in read_locks_count */ + struct new_utsname uts; /* info about machine where stats are measured */ + /* -T option of lockstat allows data to be */ + /* moved to another machine. ................. */ +} lstat_user_request_t; + +#endif /* _LINUX_LOCKMETER_H */ diff -puN include/linux/spinlock.h~lockmeter include/linux/spinlock.h --- 25/include/linux/spinlock.h~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/include/linux/spinlock.h Fri May 14 17:40:32 2004 @@ -198,6 +198,17 @@ typedef struct { #endif /* !SMP */ +#ifdef CONFIG_LOCKMETER +extern void _metered_spin_lock (spinlock_t *lock); +extern void _metered_spin_unlock (spinlock_t *lock); +extern int _metered_spin_trylock(spinlock_t *lock); +extern void _metered_read_lock (rwlock_t *lock); +extern void _metered_read_unlock (rwlock_t *lock); +extern void _metered_write_lock (rwlock_t *lock); +extern void _metered_write_unlock (rwlock_t *lock); +extern int _metered_write_trylock(rwlock_t *lock); +#endif + /* * Define the various spin_lock and rw_lock methods. Note we define these * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various @@ -403,6 +414,141 @@ do { \ _raw_spin_trylock(lock) ? 1 : \ ({preempt_enable(); local_bh_enable(); 0;});}) +#ifdef CONFIG_LOCKMETER +#undef spin_lock +#undef spin_trylock +#undef spin_unlock +#undef spin_lock_irqsave +#undef spin_lock_irq +#undef spin_lock_bh +#undef read_lock +#undef read_unlock +#undef write_lock +#undef write_unlock +#undef write_trylock +#undef spin_unlock_bh +#undef read_lock_irqsave +#undef read_lock_irq +#undef read_lock_bh +#undef read_unlock_bh +#undef write_lock_irqsave +#undef write_lock_irq +#undef write_lock_bh +#undef write_unlock_bh + +#define spin_lock(lock) \ +do { \ + preempt_disable(); \ + _metered_spin_lock(lock); \ +} while(0) + +#define spin_trylock(lock) ({preempt_disable(); _metered_spin_trylock(lock) ? \ + 1 : ({preempt_enable(); 0;});}) +#define spin_unlock(lock) \ +do { \ + _metered_spin_unlock(lock); \ + preempt_enable(); \ +} while (0) + +#define spin_lock_irqsave(lock, flags) \ +do { \ + local_irq_save(flags); \ + preempt_disable(); \ + _metered_spin_lock(lock); \ +} while (0) + +#define spin_lock_irq(lock) \ +do { \ + local_irq_disable(); \ + preempt_disable(); \ + _metered_spin_lock(lock); \ +} while (0) + +#define spin_lock_bh(lock) \ +do { \ + local_bh_disable(); \ + preempt_disable(); \ + _metered_spin_lock(lock); \ +} while (0) + +#define spin_unlock_bh(lock) \ +do { \ + _metered_spin_unlock(lock); \ + preempt_enable(); \ + local_bh_enable(); \ +} while (0) + + +#define read_lock(lock) ({preempt_disable(); _metered_read_lock(lock);}) +#define read_unlock(lock) ({_metered_read_unlock(lock); preempt_enable();}) +#define write_lock(lock) ({preempt_disable(); _metered_write_lock(lock);}) +#define write_unlock(lock) ({_metered_write_unlock(lock); preempt_enable();}) +#define write_trylock(lock) ({preempt_disable();_metered_write_trylock(lock) ? \ + 1 : ({preempt_enable(); 0;});}) +#define spin_unlock_no_resched(lock) \ +do { \ + _metered_spin_unlock(lock); \ + preempt_enable_no_resched(); \ +} while (0) + +#define read_lock_irqsave(lock, flags) \ +do { \ + local_irq_save(flags); \ + preempt_disable(); \ + _metered_read_lock(lock); \ +} while (0) + +#define read_lock_irq(lock) \ +do { \ + local_irq_disable(); \ + preempt_disable(); \ + _metered_read_lock(lock); \ +} while (0) + +#define read_lock_bh(lock) \ +do { \ + local_bh_disable(); \ + preempt_disable(); \ + _metered_read_lock(lock); \ +} while (0) + +#define read_unlock_bh(lock) \ +do { \ + _metered_read_unlock(lock); \ + preempt_enable(); \ + local_bh_enable(); \ +} while (0) + +#define write_lock_irqsave(lock, flags) \ +do { \ + local_irq_save(flags); \ + preempt_disable(); \ + _metered_write_lock(lock); \ +} while (0) + +#define write_lock_irq(lock) \ +do { \ + local_irq_disable(); \ + preempt_disable(); \ + _metered_write_lock(lock); \ +} while (0) + +#define write_lock_bh(lock) \ +do { \ + local_bh_disable(); \ + preempt_disable(); \ + _metered_write_lock(lock); \ +} while (0) + +#define write_unlock_bh(lock) \ +do { \ + _metered_write_unlock(lock); \ + preempt_enable(); \ + local_bh_enable(); \ +} while (0) + +#endif /* !CONFIG_LOCKMETER */ + /* "lock on reference count zero" */ #ifndef ATOMIC_DEC_AND_LOCK #include diff -puN /dev/null kernel/lockmeter.c --- /dev/null Thu Apr 11 07:25:15 2002 +++ 25-akpm/kernel/lockmeter.c Fri May 14 17:40:32 2004 @@ -0,0 +1,1178 @@ +/* + * Copyright (C) 1999,2000 Silicon Graphics, Inc. + * + * Written by John Hawkes (hawkes@sgi.com) + * Based on klstat.c by Jack Steiner (steiner@sgi.com) + * + * Modified by Ray Bryant (raybry@us.ibm.com) + * Changes Copyright (C) 2000 IBM, Inc. + * Added save of index in spinlock_t to improve efficiency + * of "hold" time reporting for spinlocks + * Added support for hold time statistics for read and write + * locks. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define ASSERT(cond) +#define bzero(loc,size) memset(loc,0,size) + +/*<---------------------------------------------------*/ +/* lockmeter.c */ +/*>---------------------------------------------------*/ + +static lstat_control_t lstat_control __cacheline_aligned = + { LSTAT_OFF, SPIN_LOCK_UNLOCKED, SPIN_LOCK_UNLOCKED, + 19 * 0, NR_CPUS * 0, 0, NR_CPUS * 0 }; + +static ushort lstat_make_dir_entry(void *, void *); + +/* + * lstat_lookup + * + * Given a RA, locate the directory entry for the lock. + */ +static ushort +lstat_lookup(void *lock_ptr, void *caller_ra) +{ + ushort index; + lstat_directory_entry_t *dirp; + + dirp = lstat_control.dir; + + index = lstat_control.hashtab[DIRHASH(caller_ra)]; + while (dirp[index].caller_ra != caller_ra) { + if (index == 0) { + return lstat_make_dir_entry(lock_ptr, caller_ra); + } + index = dirp[index].next_stat_index; + } + + if (dirp[index].lock_ptr != NULL && dirp[index].lock_ptr != lock_ptr) { + dirp[index].lock_ptr = NULL; + } + + return index; +} + +/* + * lstat_make_dir_entry + * Called to add a new lock to the lock directory. + */ +static ushort +lstat_make_dir_entry(void *lock_ptr, void *caller_ra) +{ + lstat_directory_entry_t *dirp; + ushort index, hindex; + unsigned long flags; + + /* lock the table without recursively reentering this metering code */ + local_irq_save(flags); + _raw_spin_lock(&lstat_control.directory_lock); + + hindex = DIRHASH(caller_ra); + index = lstat_control.hashtab[hindex]; + dirp = lstat_control.dir; + while (index && dirp[index].caller_ra != caller_ra) + index = dirp[index].next_stat_index; + + if (index == 0) { + if (lstat_control.next_free_dir_index < LSTAT_MAX_STAT_INDEX) { + index = lstat_control.next_free_dir_index++; + lstat_control.dir[index].caller_ra = caller_ra; + lstat_control.dir[index].lock_ptr = lock_ptr; + lstat_control.dir[index].next_stat_index = + lstat_control.hashtab[hindex]; + lstat_control.hashtab[hindex] = index; + } else { + lstat_control.dir_overflow++; + } + } + _raw_spin_unlock(&lstat_control.directory_lock); + local_irq_restore(flags); + return index; +} + +int +lstat_update(void *lock_ptr, void *caller_ra, int action) +{ + int index; + int cpu; + + ASSERT(action < LSTAT_ACT_MAX_VALUES); + + if (lstat_control.state == LSTAT_OFF) + return 0; + + index = lstat_lookup(lock_ptr, caller_ra); + cpu = THIS_CPU_NUMBER; + (*lstat_control.counts[cpu])[index].count[action]++; + (*lstat_control.counts[cpu])[index].acquire_time = get_cycles(); + + return index; +} + +int +lstat_update_time(void *lock_ptr, void *caller_ra, int action, uint32_t ticks) +{ + ushort index; + int cpu; + + ASSERT(action < LSTAT_ACT_MAX_VALUES); + + if (lstat_control.state == LSTAT_OFF) + return 0; + + index = lstat_lookup(lock_ptr, caller_ra); + cpu = THIS_CPU_NUMBER; + (*lstat_control.counts[cpu])[index].count[action]++; + (*lstat_control.counts[cpu])[index].cum_wait_ticks += (uint64_t) ticks; + if ((*lstat_control.counts[cpu])[index].max_wait_ticks < ticks) + (*lstat_control.counts[cpu])[index].max_wait_ticks = ticks; + + (*lstat_control.counts[cpu])[index].acquire_time = get_cycles(); + + return index; +} + +void +_metered_spin_lock(spinlock_t * lock_ptr) +{ + if (lstat_control.state == LSTAT_OFF) { + _raw_spin_lock(lock_ptr); /* do the real lock */ + PUT_INDEX(lock_ptr, 0); /* clean index in case lockmetering */ + /* gets turned on before unlock */ + } else { + void *this_pc = LSTAT_RA(LSTAT_RA_SPIN); + int index; + + if (_raw_spin_trylock(lock_ptr)) { + index = lstat_update(lock_ptr, this_pc, + LSTAT_ACT_NO_WAIT); + } else { + uint32_t start_cycles = get_cycles(); + _raw_spin_lock(lock_ptr); /* do the real lock */ + index = lstat_update_time(lock_ptr, this_pc, + LSTAT_ACT_SPIN, get_cycles() - start_cycles); + } + /* save the index in the lock itself for use in spin unlock */ + PUT_INDEX(lock_ptr, index); + } +} + +int +_metered_spin_trylock(spinlock_t * lock_ptr) +{ + if (lstat_control.state == LSTAT_OFF) { + return _raw_spin_trylock(lock_ptr); + } else { + int retval; + void *this_pc = LSTAT_RA(LSTAT_RA_SPIN); + + if ((retval = _raw_spin_trylock(lock_ptr))) { + int index = lstat_update(lock_ptr, this_pc, + LSTAT_ACT_NO_WAIT); + /* + * save the index in the lock itself for use in spin + * unlock + */ + PUT_INDEX(lock_ptr, index); + } else { + lstat_update(lock_ptr, this_pc, LSTAT_ACT_REJECT); + } + + return retval; + } +} + +void +_metered_spin_unlock(spinlock_t * lock_ptr) +{ + int index = -1; + + if (lstat_control.state != LSTAT_OFF) { + index = GET_INDEX(lock_ptr); + /* + * If statistics were turned off when we set the lock, + * then the index can be zero. If that is the case, + * then collect no stats on this call. + */ + if (index > 0) { + uint32_t hold_time; + int cpu = THIS_CPU_NUMBER; + hold_time = get_cycles() - + (*lstat_control.counts[cpu])[index].acquire_time; + (*lstat_control.counts[cpu])[index].cum_hold_ticks += + (uint64_t) hold_time; + if ((*lstat_control.counts[cpu])[index].max_hold_ticks < + hold_time) + (*lstat_control.counts[cpu])[index]. + max_hold_ticks = hold_time; + } + } + + /* make sure we don't have a stale index value saved */ + PUT_INDEX(lock_ptr, 0); + _raw_spin_unlock(lock_ptr); /* do the real unlock */ +} + +/* + * allocate the next global read lock structure and store its index + * in the rwlock at "lock_ptr". + */ +uint32_t +alloc_rwlock_struct(rwlock_t * rwlock_ptr) +{ + int index; + unsigned long flags; + int cpu = THIS_CPU_NUMBER; + + /* If we've already overflowed, then do a quick exit */ + if (lstat_control.next_free_read_lock_index > + LSTAT_MAX_READ_LOCK_INDEX) { + lstat_control.rwlock_overflow++; + return 0; + } + + local_irq_save(flags); + _raw_spin_lock(&lstat_control.directory_lock); + + /* It is possible this changed while we were waiting for the directory_lock */ + if (lstat_control.state == LSTAT_OFF) { + index = 0; + goto unlock; + } + + /* It is possible someone else got here first and set the index */ + if ((index = GET_RWINDEX(rwlock_ptr)) == 0) { + /* + * we can't turn on read stats for this lock while there are + * readers (this would mess up the running hold time sum at + * unlock time) + */ + if (RWLOCK_READERS(rwlock_ptr) != 0) { + index = 0; + goto unlock; + } + + /* + * if stats are turned on after being off, we may need to + * return an old index from when the statistics were on last + * time. + */ + for (index = 1; index < lstat_control.next_free_read_lock_index; + index++) + if ((*lstat_control.read_lock_counts[cpu])[index]. + lock_ptr == rwlock_ptr) + goto put_index_and_unlock; + + /* allocate the next global read lock structure */ + if (lstat_control.next_free_read_lock_index >= + LSTAT_MAX_READ_LOCK_INDEX) { + lstat_control.rwlock_overflow++; + index = 0; + goto unlock; + } + index = lstat_control.next_free_read_lock_index++; + + /* + * initialize the global read stats data structure for each + * cpu + */ + for (cpu = 0; cpu < num_online_cpus(); cpu++) { + (*lstat_control.read_lock_counts[cpu])[index].lock_ptr = + rwlock_ptr; + } +put_index_and_unlock: + /* store the index for the read lock structure into the lock */ + PUT_RWINDEX(rwlock_ptr, index); + } + +unlock: + _raw_spin_unlock(&lstat_control.directory_lock); + local_irq_restore(flags); + return index; +} + +void +_metered_read_lock(rwlock_t * rwlock_ptr) +{ + void *this_pc; + uint32_t start_cycles; + int index; + int cpu; + unsigned long flags; + int readers_before, readers_after; + uint64_t cycles64; + + if (lstat_control.state == LSTAT_OFF) { + _raw_read_lock(rwlock_ptr); + /* clean index in case lockmetering turns on before an unlock */ + PUT_RWINDEX(rwlock_ptr, 0); + return; + } + + this_pc = LSTAT_RA(LSTAT_RA_READ); + cpu = THIS_CPU_NUMBER; + index = GET_RWINDEX(rwlock_ptr); + + /* allocate the global stats entry for this lock, if needed */ + if (index == 0) + index = alloc_rwlock_struct(rwlock_ptr); + + readers_before = RWLOCK_READERS(rwlock_ptr); + if (_raw_read_trylock(rwlock_ptr)) { + /* + * We have decremented the lock to count a new reader, + * and have confirmed that no writer has it locked. + */ + /* update statistics if enabled */ + if (index > 0) { + local_irq_save(flags); + lstat_update((void *) rwlock_ptr, this_pc, + LSTAT_ACT_NO_WAIT); + /* preserve value of TSC so cum_hold_ticks and start_busy use same value */ + cycles64 = get_cycles64(); + (*lstat_control.read_lock_counts[cpu])[index]. + cum_hold_ticks -= cycles64; + + /* record time and cpu of start of busy period */ + /* this is not perfect (some race conditions are possible) */ + if (readers_before == 0) { + (*lstat_control.read_lock_counts[cpu])[index]. + start_busy = cycles64; + PUT_RW_CPU(rwlock_ptr, cpu); + } + readers_after = RWLOCK_READERS(rwlock_ptr); + if (readers_after > + (*lstat_control.read_lock_counts[cpu])[index]. + max_readers) + (*lstat_control.read_lock_counts[cpu])[index]. + max_readers = readers_after; + local_irq_restore(flags); + } + + return; + } + /* If we get here, then we could not quickly grab the read lock */ + + start_cycles = get_cycles(); /* start counting the wait time */ + + /* Now spin until read_lock is successful */ + _raw_read_lock(rwlock_ptr); + + lstat_update_time((void *) rwlock_ptr, this_pc, LSTAT_ACT_SPIN, + get_cycles() - start_cycles); + + /* update statistics if they are enabled for this lock */ + if (index > 0) { + local_irq_save(flags); + cycles64 = get_cycles64(); + (*lstat_control.read_lock_counts[cpu])[index].cum_hold_ticks -= + cycles64; + + /* this is not perfect (some race conditions are possible) */ + if (readers_before == 0) { + (*lstat_control.read_lock_counts[cpu])[index]. + start_busy = cycles64; + PUT_RW_CPU(rwlock_ptr, cpu); + } + readers_after = RWLOCK_READERS(rwlock_ptr); + if (readers_after > + (*lstat_control.read_lock_counts[cpu])[index].max_readers) + (*lstat_control.read_lock_counts[cpu])[index]. + max_readers = readers_after; + local_irq_restore(flags); + } +} + +void +_metered_read_unlock(rwlock_t * rwlock_ptr) +{ + int index; + int cpu; + unsigned long flags; + uint64_t busy_length; + uint64_t cycles64; + + if (lstat_control.state == LSTAT_OFF) { + _raw_read_unlock(rwlock_ptr); + return; + } + + index = GET_RWINDEX(rwlock_ptr); + cpu = THIS_CPU_NUMBER; + + if (index > 0) { + local_irq_save(flags); + /* + * preserve value of TSC so cum_hold_ticks and busy_ticks are + * consistent. + */ + cycles64 = get_cycles64(); + (*lstat_control.read_lock_counts[cpu])[index].cum_hold_ticks += + cycles64; + (*lstat_control.read_lock_counts[cpu])[index].read_lock_count++; + + /* + * once again, this is not perfect (some race conditions are + * possible) + */ + if (RWLOCK_READERS(rwlock_ptr) == 1) { + int cpu1 = GET_RW_CPU(rwlock_ptr); + uint64_t last_start_busy = + (*lstat_control.read_lock_counts[cpu1])[index]. + start_busy; + (*lstat_control.read_lock_counts[cpu])[index]. + busy_periods++; + if (cycles64 > last_start_busy) { + busy_length = cycles64 - last_start_busy; + (*lstat_control.read_lock_counts[cpu])[index]. + busy_ticks += busy_length; + if (busy_length > + (*lstat_control. + read_lock_counts[cpu])[index]. + max_busy) + (*lstat_control. + read_lock_counts[cpu])[index]. + max_busy = busy_length; + } + } + local_irq_restore(flags); + } + _raw_read_unlock(rwlock_ptr); +} + +void +_metered_write_lock(rwlock_t * rwlock_ptr) +{ + uint32_t start_cycles; + void *this_pc; + uint32_t spin_ticks = 0; /* in anticipation of a potential wait */ + int index; + int write_index = 0; + int cpu; + enum { + writer_writer_conflict, + writer_reader_conflict + } why_wait = writer_writer_conflict; + + if (lstat_control.state == LSTAT_OFF) { + _raw_write_lock(rwlock_ptr); + /* clean index in case lockmetering turns on before an unlock */ + PUT_RWINDEX(rwlock_ptr, 0); + return; + } + + this_pc = LSTAT_RA(LSTAT_RA_WRITE); + cpu = THIS_CPU_NUMBER; + index = GET_RWINDEX(rwlock_ptr); + + /* allocate the global stats entry for this lock, if needed */ + if (index == 0) { + index = alloc_rwlock_struct(rwlock_ptr); + } + + if (_raw_write_trylock(rwlock_ptr)) { + /* We acquired the lock on the first try */ + write_index = lstat_update((void *) rwlock_ptr, this_pc, + LSTAT_ACT_NO_WAIT); + /* save the write_index for use in unlock if stats enabled */ + if (index > 0) + (*lstat_control.read_lock_counts[cpu])[index]. + write_index = write_index; + return; + } + + /* If we get here, then we could not quickly grab the write lock */ + start_cycles = get_cycles(); /* start counting the wait time */ + + why_wait = RWLOCK_READERS(rwlock_ptr) ? + writer_reader_conflict : writer_writer_conflict; + + /* Now set the lock and wait for conflicts to disappear */ + _raw_write_lock(rwlock_ptr); + + spin_ticks = get_cycles() - start_cycles; + + /* update stats -- if enabled */ + if (index > 0 && spin_ticks) { + if (why_wait == writer_reader_conflict) { + /* waited due to a reader holding the lock */ + write_index = lstat_update_time((void *)rwlock_ptr, + this_pc, LSTAT_ACT_SPIN, spin_ticks); + } else { + /* + * waited due to another writer holding the lock + */ + write_index = lstat_update_time((void *)rwlock_ptr, + this_pc, LSTAT_ACT_WW_SPIN, spin_ticks); + (*lstat_control.counts[cpu])[write_index]. + cum_wait_ww_ticks += spin_ticks; + if (spin_ticks > + (*lstat_control.counts[cpu])[write_index]. + max_wait_ww_ticks) { + (*lstat_control.counts[cpu])[write_index]. + max_wait_ww_ticks = spin_ticks; + } + } + + /* save the directory index for use on write_unlock */ + (*lstat_control.read_lock_counts[cpu])[index]. + write_index = write_index; + } +} + +void +_metered_write_unlock(rwlock_t * rwlock_ptr) +{ + int index; + int cpu; + int write_index; + uint32_t hold_time; + + if (lstat_control.state == LSTAT_OFF) { + _raw_write_unlock(rwlock_ptr); + return; + } + + cpu = THIS_CPU_NUMBER; + index = GET_RWINDEX(rwlock_ptr); + + /* update statistics if stats enabled for this lock */ + if (index > 0) { + write_index = + (*lstat_control.read_lock_counts[cpu])[index].write_index; + + hold_time = get_cycles() - + (*lstat_control.counts[cpu])[write_index].acquire_time; + (*lstat_control.counts[cpu])[write_index].cum_hold_ticks += + (uint64_t) hold_time; + if ((*lstat_control.counts[cpu])[write_index].max_hold_ticks < + hold_time) + (*lstat_control.counts[cpu])[write_index]. + max_hold_ticks = hold_time; + } + _raw_write_unlock(rwlock_ptr); +} + +int +_metered_write_trylock(rwlock_t * rwlock_ptr) +{ + int retval; + void *this_pc = LSTAT_RA(LSTAT_RA_WRITE); + + if ((retval = _raw_write_trylock(rwlock_ptr))) { + lstat_update(rwlock_ptr, this_pc, LSTAT_ACT_NO_WAIT); + } else { + lstat_update(rwlock_ptr, this_pc, LSTAT_ACT_REJECT); + } + + return retval; +} + +static void +init_control_space(void) +{ + /* Set all control space pointers to null and indices to "empty" */ + int cpu; + + /* + * Access CPU_CYCLE_FREQUENCY at the outset, which in some + * architectures may trigger a runtime calculation that uses a + * spinlock. Let's do this before lockmetering is turned on. + */ + if (CPU_CYCLE_FREQUENCY == 0) + BUG(); + + lstat_control.hashtab = NULL; + lstat_control.dir = NULL; + for (cpu = 0; cpu < NR_CPUS; cpu++) { + lstat_control.counts[cpu] = NULL; + lstat_control.read_lock_counts[cpu] = NULL; + } +} + +static int +reset_lstat_data(void) +{ + int cpu, flags; + + flags = 0; + lstat_control.next_free_dir_index = 1; /* 0 is for overflows */ + lstat_control.next_free_read_lock_index = 1; + lstat_control.dir_overflow = 0; + lstat_control.rwlock_overflow = 0; + + lstat_control.started_cycles64 = 0; + lstat_control.ending_cycles64 = 0; + lstat_control.enabled_cycles64 = 0; + lstat_control.first_started_time = 0; + lstat_control.started_time = 0; + lstat_control.ending_time = 0; + lstat_control.intervals = 0; + + /* + * paranoia -- in case someone does a "lockstat reset" before + * "lockstat on" + */ + if (lstat_control.hashtab) { + bzero(lstat_control.hashtab, + LSTAT_HASH_TABLE_SIZE * sizeof (short)); + bzero(lstat_control.dir, LSTAT_MAX_STAT_INDEX * + sizeof (lstat_directory_entry_t)); + + for (cpu = 0; cpu < num_online_cpus(); cpu++) { + bzero(lstat_control.counts[cpu], + sizeof (lstat_cpu_counts_t)); + bzero(lstat_control.read_lock_counts[cpu], + sizeof (lstat_read_lock_cpu_counts_t)); + } + } +#ifdef NOTDEF + _raw_spin_unlock(&lstat_control.directory_lock); + local_irq_restore(flags); +#endif + return 1; +} + +static void +release_control_space(void) +{ + /* + * Called when either (1) allocation of kmem + * or (2) when user writes LSTAT_RELEASE to /pro/lockmeter. + * Assume that all pointers have been initialized to zero, + * i.e., nonzero pointers are valid addresses. + */ + int cpu; + + if (lstat_control.hashtab) { + kfree(lstat_control.hashtab); + lstat_control.hashtab = NULL; + } + + if (lstat_control.dir) { + vfree(lstat_control.dir); + lstat_control.dir = NULL; + } + + for (cpu = 0; cpu < NR_CPUS; cpu++) { + if (lstat_control.counts[cpu]) { + vfree(lstat_control.counts[cpu]); + lstat_control.counts[cpu] = NULL; + } + if (lstat_control.read_lock_counts[cpu]) { + kfree(lstat_control.read_lock_counts[cpu]); + lstat_control.read_lock_counts[cpu] = NULL; + } + } +} + +int +get_lockmeter_info_size(void) +{ + return sizeof (lstat_user_request_t) + + num_online_cpus() * sizeof (lstat_cpu_counts_t) + + num_online_cpus() * sizeof (lstat_read_lock_cpu_counts_t) + + (LSTAT_MAX_STAT_INDEX * sizeof (lstat_directory_entry_t)); +} + +ssize_t +get_lockmeter_info(char *buffer, size_t max_len, loff_t * last_index) +{ + lstat_user_request_t req; + struct timeval tv; + ssize_t next_ret_bcount; + ssize_t actual_ret_bcount = 0; + int cpu; + + *last_index = 0; /* a one-shot read */ + + req.lstat_version = LSTAT_VERSION; + req.state = lstat_control.state; + req.maxcpus = num_online_cpus(); + req.cycleval = CPU_CYCLE_FREQUENCY; +#ifdef notyet + req.kernel_magic_addr = (void *) &_etext; + req.kernel_end_addr = (void *) &_etext; +#endif + req.uts = system_utsname; + req.intervals = lstat_control.intervals; + + req.first_started_time = lstat_control.first_started_time; + req.started_time = lstat_control.started_time; + req.started_cycles64 = lstat_control.started_cycles64; + + req.next_free_dir_index = lstat_control.next_free_dir_index; + req.next_free_read_lock_index = lstat_control.next_free_read_lock_index; + req.dir_overflow = lstat_control.dir_overflow; + req.rwlock_overflow = lstat_control.rwlock_overflow; + + if (lstat_control.state == LSTAT_OFF) { + if (req.intervals == 0) { + /* mesasurement is off and no valid data present */ + next_ret_bcount = sizeof (lstat_user_request_t); + req.enabled_cycles64 = 0; + + if ((actual_ret_bcount + next_ret_bcount) > max_len) + return actual_ret_bcount; + + copy_to_user(buffer, (void *) &req, next_ret_bcount); + actual_ret_bcount += next_ret_bcount; + return actual_ret_bcount; + } else { + /* + * measurement is off but valid data present + * fetch time info from lstat_control + */ + req.ending_time = lstat_control.ending_time; + req.ending_cycles64 = lstat_control.ending_cycles64; + req.enabled_cycles64 = lstat_control.enabled_cycles64; + } + } else { + /* + * this must be a read while data active--use current time, + * etc + */ + do_gettimeofday(&tv); + req.ending_time = tv.tv_sec; + req.ending_cycles64 = get_cycles64(); + req.enabled_cycles64 = req.ending_cycles64 - + req.started_cycles64 + lstat_control.enabled_cycles64; + } + + next_ret_bcount = sizeof (lstat_user_request_t); + if ((actual_ret_bcount + next_ret_bcount) > max_len) + return actual_ret_bcount; + + copy_to_user(buffer, (void *) &req, next_ret_bcount); + actual_ret_bcount += next_ret_bcount; + + if (!lstat_control.counts[0]) /* not initialized? */ + return actual_ret_bcount; + + next_ret_bcount = sizeof (lstat_cpu_counts_t); + for (cpu = 0; cpu < num_online_cpus(); cpu++) { + if ((actual_ret_bcount + next_ret_bcount) > max_len) + return actual_ret_bcount; /* leave early */ + copy_to_user(buffer + actual_ret_bcount, + lstat_control.counts[cpu], next_ret_bcount); + actual_ret_bcount += next_ret_bcount; + } + + next_ret_bcount = LSTAT_MAX_STAT_INDEX * + sizeof (lstat_directory_entry_t); + if (((actual_ret_bcount + next_ret_bcount) > max_len) + || !lstat_control.dir) + return actual_ret_bcount; /* leave early */ + + copy_to_user(buffer + actual_ret_bcount, lstat_control.dir, + next_ret_bcount); + actual_ret_bcount += next_ret_bcount; + + next_ret_bcount = sizeof (lstat_read_lock_cpu_counts_t); + for (cpu = 0; cpu < num_online_cpus(); cpu++) { + if (actual_ret_bcount + next_ret_bcount > max_len) + return actual_ret_bcount; + copy_to_user(buffer + actual_ret_bcount, + lstat_control.read_lock_counts[cpu], + next_ret_bcount); + actual_ret_bcount += next_ret_bcount; + } + + return actual_ret_bcount; +} + +/* + * Writing to the /proc lockmeter node enables or disables metering. + * based upon the first byte of the "written" data. + * The following values are defined: + * LSTAT_ON: 1st call: allocates storage, intializes and turns on measurement + * subsequent calls just turn on measurement + * LSTAT_OFF: turns off measurement + * LSTAT_RESET: resets statistics + * LSTAT_RELEASE: releases statistics storage + * + * This allows one to accumulate statistics over several lockstat runs: + * + * lockstat on + * lockstat off + * ...repeat above as desired... + * lockstat get + * ...now start a new set of measurements... + * lockstat reset + * lockstat on + * ... + * + */ +ssize_t +put_lockmeter_info(const char *buffer, size_t len) +{ + int error = 0; + int dirsize, countsize, read_lock_countsize, hashsize; + int cpu; + char put_char; + int i, read_lock_blocks; + unsigned long flags; + rwlock_t *lock_ptr; + struct timeval tv; + + if (len <= 0) + return -EINVAL; + + _raw_spin_lock(&lstat_control.control_lock); + + get_user(put_char, buffer); + switch (put_char) { + + case LSTAT_OFF: + if (lstat_control.state != LSTAT_OFF) { + /* + * To avoid seeing read lock hold times in an + * inconsisent state, we have to follow this protocol + * to turn off statistics + */ + local_irq_save(flags); + /* + * getting this lock will stop any read lock block + * allocations + */ + _raw_spin_lock(&lstat_control.directory_lock); + /* + * keep any more read lock blocks from being + * allocated + */ + lstat_control.state = LSTAT_OFF; + /* record how may read lock blocks there are */ + read_lock_blocks = + lstat_control.next_free_read_lock_index; + _raw_spin_unlock(&lstat_control.directory_lock); + /* now go through the list of read locks */ + cpu = THIS_CPU_NUMBER; + for (i = 1; i < read_lock_blocks; i++) { + lock_ptr = + (*lstat_control.read_lock_counts[cpu])[i]. + lock_ptr; + /* is this saved lock address still valid? */ + if (GET_RWINDEX(lock_ptr) == i) { + /* + * lock address appears to still be + * valid because we only hold one lock + * at a time, this can't cause a + * deadlock unless this is a lock held + * as part of the current system call + * path. At the moment there + * are no READ mode locks held to get + * here from user space, so we solve + * this by skipping locks held in + * write mode. + */ + if (RWLOCK_IS_WRITE_LOCKED(lock_ptr)) { + PUT_RWINDEX(lock_ptr, 0); + continue; + } + /* + * now we know there are no read + * holders of this lock! stop + * statistics collection for this + * lock + */ + _raw_write_lock(lock_ptr); + PUT_RWINDEX(lock_ptr, 0); + _raw_write_unlock(lock_ptr); + } + /* + * it may still be possible for the hold time + * sum to be negative e.g. if a lock is + * reallocated while "busy" we will have to fix + * this up in the data reduction program. + */ + } + local_irq_restore(flags); + lstat_control.intervals++; + lstat_control.ending_cycles64 = get_cycles64(); + lstat_control.enabled_cycles64 += + lstat_control.ending_cycles64 - + lstat_control.started_cycles64; + do_gettimeofday(&tv); + lstat_control.ending_time = tv.tv_sec; + /* + * don't deallocate the structures -- we may do a + * lockstat on to add to the data that is already + * there. Use LSTAT_RELEASE to release storage + */ + } else { + error = -EBUSY; /* already OFF */ + } + break; + + case LSTAT_ON: + if (lstat_control.state == LSTAT_OFF) { +#ifdef DEBUG_LOCKMETER + printk("put_lockmeter_info(cpu=%d): LSTAT_ON\n", + THIS_CPU_NUMBER); +#endif + lstat_control.next_free_dir_index = 1; /* 0 is for overflows */ + + dirsize = LSTAT_MAX_STAT_INDEX * + sizeof (lstat_directory_entry_t); + hashsize = + (1 + LSTAT_HASH_TABLE_SIZE) * sizeof (ushort); + countsize = sizeof (lstat_cpu_counts_t); + read_lock_countsize = + sizeof (lstat_read_lock_cpu_counts_t); +#ifdef DEBUG_LOCKMETER + printk(" dirsize:%d", dirsize); + printk(" hashsize:%d", hashsize); + printk(" countsize:%d", countsize); + printk(" read_lock_countsize:%d\n", + read_lock_countsize); +#endif +#ifdef DEBUG_LOCKMETER + { + int secs; + unsigned long cycles; + uint64_t cycles64; + + do_gettimeofday(&tv); + secs = tv.tv_sec; + do { + do_gettimeofday(&tv); + } while (secs == tv.tv_sec); + cycles = get_cycles(); + cycles64 = get_cycles64(); + secs = tv.tv_sec; + do { + do_gettimeofday(&tv); + } while (secs == tv.tv_sec); + cycles = get_cycles() - cycles; + cycles64 = get_cycles64() - cycles; + printk("lockmeter: cycleFrequency:%d " + "cycles:%d cycles64:%d\n", + CPU_CYCLE_FREQUENCY, cycles, cycles64); + } +#endif + + /* + * if this is the first call, allocate storage and + * initialize + */ + if (!lstat_control.hashtab) { + + spin_lock_init(&lstat_control.directory_lock); + + /* guarantee all pointers at zero */ + init_control_space(); + + lstat_control.hashtab = + kmalloc(hashsize, GFP_KERNEL); + if (!lstat_control.hashtab) { + error = -ENOSPC; +#ifdef DEBUG_LOCKMETER + printk("!!error kmalloc of hashtab\n"); +#endif + } + lstat_control.dir = vmalloc(dirsize); + if (!lstat_control.dir) { + error = -ENOSPC; +#ifdef DEBUG_LOCKMETER + printk("!!error kmalloc of dir\n"); +#endif + } + + for (cpu = 0; cpu < num_online_cpus(); cpu++) { + lstat_control.counts[cpu] = + vmalloc(countsize); + if (!lstat_control.counts[cpu]) { + error = -ENOSPC; +#ifdef DEBUG_LOCKMETER + printk("!!error vmalloc of " + "counts[%d]\n", cpu); +#endif + } + lstat_control.read_lock_counts[cpu] = + (lstat_read_lock_cpu_counts_t *) + kmalloc(read_lock_countsize, + GFP_KERNEL); + if (!lstat_control. + read_lock_counts[cpu]) { + error = -ENOSPC; +#ifdef DEBUG_LOCKMETER + printk("!!error kmalloc of " + "read_lock_counts[%d]\n", + cpu); +#endif + } + } + } + + if (error) { + /* + * One or more kmalloc failures -- free + * everything + */ + release_control_space(); + } else { + + if (!reset_lstat_data()) { + error = -EINVAL; + break; + }; + + /* + * record starting and ending times and the + * like + */ + if (lstat_control.intervals == 0) { + do_gettimeofday(&tv); + lstat_control.first_started_time = + tv.tv_sec; + } + lstat_control.started_cycles64 = get_cycles64(); + do_gettimeofday(&tv); + lstat_control.started_time = tv.tv_sec; + + lstat_control.state = LSTAT_ON; + } + } else { + error = -EBUSY; /* already ON */ + } + break; + + case LSTAT_RESET: + if (lstat_control.state == LSTAT_OFF) { + if (!reset_lstat_data()) + error = -EINVAL; + } else { + error = -EBUSY; /* still on; can't reset */ + } + break; + + case LSTAT_RELEASE: + if (lstat_control.state == LSTAT_OFF) { + release_control_space(); + lstat_control.intervals = 0; + lstat_control.enabled_cycles64 = 0; + } else { + error = -EBUSY; + } + break; + + default: + error = -EINVAL; + } /* switch */ + + _raw_spin_unlock(&lstat_control.control_lock); + return error ? error : len; +} + +#ifdef USER_MODE_TESTING +/* following used for user mode testing */ +void +lockmeter_init() +{ + int dirsize, hashsize, countsize, read_lock_countsize, cpu; + + printf("lstat_control is at %x size=%d\n", &lstat_control, + sizeof (lstat_control)); + printf("sizeof(spinlock_t)=%d\n", sizeof (spinlock_t)); + lstat_control.state = LSTAT_ON; + + lstat_control.directory_lock = SPIN_LOCK_UNLOCKED; + lstat_control.next_free_dir_index = 1; /* 0 is for overflows */ + lstat_control.next_free_read_lock_index = 1; + + dirsize = LSTAT_MAX_STAT_INDEX * sizeof (lstat_directory_entry_t); + hashsize = (1 + LSTAT_HASH_TABLE_SIZE) * sizeof (ushort); + countsize = sizeof (lstat_cpu_counts_t); + read_lock_countsize = sizeof (lstat_read_lock_cpu_counts_t); + + lstat_control.hashtab = (ushort *) malloc(hashsize); + + if (lstat_control.hashtab == 0) { + printf("malloc failure for at line %d in lockmeter.c\n", + __LINE__); + exit(0); + } + + lstat_control.dir = (lstat_directory_entry_t *) malloc(dirsize); + + if (lstat_control.dir == 0) { + printf("malloc failure for at line %d in lockmeter.c\n", cpu, + __LINE__); + exit(0); + } + + for (cpu = 0; cpu < num_online_cpus(); cpu++) { + int j, k; + j = (int) (lstat_control.counts[cpu] = + (lstat_cpu_counts_t *) malloc(countsize)); + k = (int) (lstat_control.read_lock_counts[cpu] = + (lstat_read_lock_cpu_counts_t *) + malloc(read_lock_countsize)); + if (j * k == 0) { + printf("malloc failure for cpu=%d at line %d in " + "lockmeter.c\n", cpu, __LINE__); + exit(0); + } + } + + memset(lstat_control.hashtab, 0, hashsize); + memset(lstat_control.dir, 0, dirsize); + + for (cpu = 0; cpu < num_online_cpus(); cpu++) { + memset(lstat_control.counts[cpu], 0, countsize); + memset(lstat_control.read_lock_counts[cpu], 0, + read_lock_countsize); + } +} + +asm(" \ +.align 4 \ +.globl __write_lock_failed \ +__write_lock_failed: \ + " LOCK "addl $" RW_LOCK_BIAS_STR ",(%eax) \ +1: cmpl $" RW_LOCK_BIAS_STR ",(%eax) \ + jne 1b \ +\ + " LOCK "subl $" RW_LOCK_BIAS_STR ",(%eax) \ + jnz __write_lock_failed \ + ret \ +\ +\ +.align 4 \ +.globl __read_lock_failed \ +__read_lock_failed: \ + lock ; incl (%eax) \ +1: cmpl $1,(%eax) \ + js 1b \ +\ + lock ; decl (%eax) \ + js __read_lock_failed \ + ret \ +"); +#endif + +EXPORT_SYMBOL(_metered_spin_lock); +EXPORT_SYMBOL(_metered_spin_unlock); +EXPORT_SYMBOL(_metered_spin_trylock); +EXPORT_SYMBOL(_metered_read_lock); +EXPORT_SYMBOL(_metered_read_unlock); +EXPORT_SYMBOL(_metered_write_lock); +EXPORT_SYMBOL(_metered_write_unlock); diff -puN kernel/Makefile~lockmeter kernel/Makefile --- 25/kernel/Makefile~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/kernel/Makefile Fri May 14 17:40:32 2004 @@ -12,6 +12,7 @@ obj-y = sched.o fork.o exec_domain.o obj-$(CONFIG_FUTEX) += futex.o obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o obj-$(CONFIG_SMP) += cpu.o +obj-$(CONFIG_LOCKMETER) += lockmeter.o obj-$(CONFIG_UID16) += uid16.o obj-$(CONFIG_MODULES) += module.o obj-$(CONFIG_KALLSYMS) += kallsyms.o diff -puN arch/ia64/Kconfig~lockmeter arch/ia64/Kconfig --- 25/arch/ia64/Kconfig~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/arch/ia64/Kconfig Fri May 14 17:40:32 2004 @@ -685,6 +685,13 @@ config DEBUG_INFO Say Y here only if you plan to use gdb to debug the kernel. If you don't debug the kernel, you can say N. +config LOCKMETER + bool "Kernel lock metering" + depends on SMP + help + Say Y to enable kernel lock metering, which adds overhead to SMP locks, + but allows you to see various statistics using the lockstat command. + config SYSVIPC_COMPAT bool depends on COMPAT && SYSVIPC diff -puN arch/ia64/lib/dec_and_lock.c~lockmeter arch/ia64/lib/dec_and_lock.c --- 25/arch/ia64/lib/dec_and_lock.c~lockmeter Fri May 14 17:40:32 2004 +++ 25-akpm/arch/ia64/lib/dec_and_lock.c Fri May 14 17:40:32 2004 @@ -13,6 +13,7 @@ #include #include +#ifndef CONFIG_LOCKMETER /* * Decrement REFCOUNT and if the count reaches zero, acquire the spinlock. Both of these * operations have to be done atomically, so that the count doesn't drop to zero without @@ -40,3 +41,4 @@ atomic_dec_and_lock (atomic_t *refcount, } EXPORT_SYMBOL(atomic_dec_and_lock); +#endif _