Make 4k stacks permanent


---

 25-akpm/arch/i386/Kconfig              |    9 --------
 25-akpm/arch/i386/kernel/irq.c         |   37 +++++++--------------------------
 25-akpm/include/asm-i386/irq.h         |    4 ---
 25-akpm/include/asm-i386/module.h      |    4 ---
 25-akpm/include/asm-i386/thread_info.h |    6 -----
 5 files changed, 9 insertions(+), 51 deletions(-)

diff -puN arch/i386/Kconfig~make-4k-stacks-permanent arch/i386/Kconfig
--- 25/arch/i386/Kconfig~make-4k-stacks-permanent	2004-05-09 21:48:44.231627368 -0700
+++ 25-akpm/arch/i386/Kconfig	2004-05-09 21:48:44.239626152 -0700
@@ -1476,15 +1476,6 @@ config FRAME_POINTER
 	  If you don't debug the kernel, you can say N, but we may not be able
 	  to solve problems without frame pointers.
 
-config 4KSTACKS
-	bool "Use 4Kb for kernel stacks instead of 8Kb"
-	help
-	  If you say Y here the kernel will use a 4Kb stacksize for the
-	  kernel stack attached to each process/thread. This facilitates
-	  running more threads on a system and also reduces the pressure
-	  on the VM subsystem for higher order allocations. This option
-	  will also use IRQ stacks to compensate for the reduced stackspace.
-
 config SCHEDSTATS
 	bool "Collect scheduler statistics"
 	depends on PROC_FS
diff -puN arch/i386/kernel/irq.c~make-4k-stacks-permanent arch/i386/kernel/irq.c
--- 25/arch/i386/kernel/irq.c~make-4k-stacks-permanent	2004-05-09 21:48:44.232627216 -0700
+++ 25-akpm/arch/i386/kernel/irq.c	2004-05-09 21:48:44.240626000 -0700
@@ -76,10 +76,8 @@ static void register_irq_proc (unsigned 
 /*
  * per-CPU IRQ handling stacks
  */
-#ifdef CONFIG_4KSTACKS
 union irq_ctx *hardirq_ctx[NR_CPUS];
 union irq_ctx *softirq_ctx[NR_CPUS];
-#endif
 
 /*
  * Special irq handlers.
@@ -487,8 +485,6 @@ asmlinkage unsigned int do_IRQ(struct pt
 	 * useful for irq hardware that does not mask cleanly in an
 	 * SMP environment.
 	 */
-#ifdef CONFIG_4KSTACKS
-
 	for (;;) {
 		irqreturn_t action_ret;
 		u32 *isp;
@@ -501,9 +497,10 @@ asmlinkage unsigned int do_IRQ(struct pt
 		spin_unlock(&desc->lock);
 
 		/*
-		 * this is where we switch to the IRQ stack. However, if we are already using
-		 * the IRQ stack (because we interrupted a hardirq handler) we can't do that
-		 * and just have to keep using the current stack (which is the irq stack already
+		 * this is where we switch to the IRQ stack. However, if we are
+		 * already using the IRQ stack (because we interrupted a
+		 * hardirq handler) we can't do that and just have to keep
+		 * using the current stack (which is the irq stack already
 		 * after all)
 		 */
 
@@ -540,23 +537,6 @@ asmlinkage unsigned int do_IRQ(struct pt
 		desc->status &= ~IRQ_PENDING;
 	}
 
-#else
-
-	for (;;) {
-		irqreturn_t action_ret;
-
-		spin_unlock(&desc->lock);
-
-		action_ret = handle_IRQ_event(irq, &regs, action);
-
-		spin_lock(&desc->lock);
-		if (!noirqdebug)
-			note_interrupt(irq, desc, action_ret);
-		if (likely(!(desc->status & IRQ_PENDING)))
-			break;
-		desc->status &= ~IRQ_PENDING;
-	}
-#endif
 	desc->status &= ~IRQ_INPROGRESS;
 
 out:
@@ -1117,9 +1097,10 @@ void init_irq_proc (void)
 }
 
 
-#ifdef CONFIG_4KSTACKS
-static char softirq_stack[NR_CPUS * THREAD_SIZE]  __attribute__((__aligned__(THREAD_SIZE)));
-static char hardirq_stack[NR_CPUS * THREAD_SIZE]  __attribute__((__aligned__(THREAD_SIZE)));
+static char softirq_stack[NR_CPUS * THREAD_SIZE]
+	__attribute__((__aligned__(THREAD_SIZE)));
+static char hardirq_stack[NR_CPUS * THREAD_SIZE]
+	__attribute__((__aligned__(THREAD_SIZE)));
 
 /*
  * allocate per-cpu stacks for hardirq and for softirq processing
@@ -1189,6 +1170,4 @@ asmlinkage void do_softirq(void)
 
 	local_irq_restore(flags);
 }
-
 EXPORT_SYMBOL(do_softirq);
-#endif
diff -puN include/asm-i386/irq.h~make-4k-stacks-permanent include/asm-i386/irq.h
--- 25/include/asm-i386/irq.h~make-4k-stacks-permanent	2004-05-09 21:48:44.233627064 -0700
+++ 25-akpm/include/asm-i386/irq.h	2004-05-09 21:48:44.241625848 -0700
@@ -31,7 +31,6 @@ extern int can_request_irq(unsigned int,
 #define ARCH_HAS_NMI_WATCHDOG		/* See include/linux/nmi.h */
 #endif
 
-#ifdef CONFIG_4KSTACKS
 /*
  * per-CPU IRQ handling contexts (thread information and stack)
  */
@@ -46,9 +45,6 @@ extern union irq_ctx *softirq_ctx[NR_CPU
 extern void irq_ctx_init(int cpu);
 
 #define __ARCH_HAS_DO_SOFTIRQ
-#else
-#define irq_ctx_init(cpu) do { ; } while (0)
-#endif
 
 struct irqaction;
 struct pt_regs;
diff -puN include/asm-i386/thread_info.h~make-4k-stacks-permanent include/asm-i386/thread_info.h
--- 25/include/asm-i386/thread_info.h~make-4k-stacks-permanent	2004-05-09 21:48:44.235626760 -0700
+++ 25-akpm/include/asm-i386/thread_info.h	2004-05-09 21:48:44.241625848 -0700
@@ -60,13 +60,9 @@ struct thread_info {
 #endif
 
 #define PREEMPT_ACTIVE		0x4000000
-#ifdef CONFIG_4KSTACKS
 #define THREAD_SIZE            (4096)
-#else
-#define THREAD_SIZE		(8192)
-#endif
-
 #define STACK_WARN             (THREAD_SIZE/8)
+
 /*
  * macros/functions for gaining access to the thread information structure
  *
diff -puN include/asm-i386/module.h~make-4k-stacks-permanent include/asm-i386/module.h
--- 25/include/asm-i386/module.h~make-4k-stacks-permanent	2004-05-09 21:48:45.806387968 -0700
+++ 25-akpm/include/asm-i386/module.h	2004-05-09 21:48:45.808387664 -0700
@@ -60,11 +60,7 @@ struct mod_arch_specific
 #define MODULE_REGPARM ""
 #endif
 
-#ifdef CONFIG_4KSTACKS
 #define MODULE_STACKSIZE "4KSTACKS "
-#else
-#define MODULE_STACKSIZE ""
-#endif
 
 #define MODULE_ARCH_VERMAGIC MODULE_PROC_FAMILY MODULE_REGPARM MODULE_STACKSIZE
 

_