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author | Robert Love <rml@tech9.net> | 2002-04-09 04:02:50 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@penguin.transmeta.com> | 2002-04-09 04:02:50 -0700 |
commit | 22e962f9b7a7abbc2d17ceaf3917bb8e67b68a8f (patch) | |
tree | e5a8c26a9b54e7aa0edb64ec9df335dfabe72c71 | |
parent | b96ad24ad44794ee435987291c83b77e6c6f96ac (diff) | |
download | history-22e962f9b7a7abbc2d17ceaf3917bb8e67b68a8f.tar.gz |
[PATCH] cpu affinity syscallsv2.5.8-pre3
This patch implements the following calls to set and retrieve a task's
CPU affinity:
int sched_setaffinity(pid_t pid, unsigned int len,
unsigned long *new_mask_ptr)
int ched_getaffinity(pid_t pid, unsigned int len,
unsigned long *user_mask_ptr)
-rw-r--r-- | arch/i386/kernel/entry.S | 2 | ||||
-rw-r--r-- | include/asm-i386/unistd.h | 2 | ||||
-rw-r--r-- | kernel/sched.c | 90 |
3 files changed, 94 insertions, 0 deletions
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S index 2bac29ee19635..ad7efb83dd769 100644 --- a/arch/i386/kernel/entry.S +++ b/arch/i386/kernel/entry.S @@ -779,6 +779,8 @@ ENTRY(sys_call_table) .long SYMBOL_NAME(sys_tkill) .long SYMBOL_NAME(sys_sendfile64) .long SYMBOL_NAME(sys_futex) /* 240 */ + .long SYMBOL_NAME(sys_sched_setaffinity) + .long SYMBOL_NAME(sys_sched_getaffinity) .rept NR_syscalls-(.-sys_call_table)/4 .long SYMBOL_NAME(sys_ni_syscall) diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h index 2cdad510f2b91..42517b85939b1 100644 --- a/include/asm-i386/unistd.h +++ b/include/asm-i386/unistd.h @@ -245,6 +245,8 @@ #define __NR_tkill 238 #define __NR_sendfile64 239 #define __NR_futex 240 +#define __NR_sched_setaffinity 241 +#define __NR_sched_getaffinity 242 /* user-visible error numbers are in the range -1 - -124: see <asm-i386/errno.h> */ diff --git a/kernel/sched.c b/kernel/sched.c index d1df13d565e22..bf8c9a91e0080 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1234,6 +1234,96 @@ out_unlock: return retval; } +/** + * sys_sched_setaffinity - set the cpu affinity of a process + * @pid: pid of the process + * @len: length of new_mask + * @new_mask: user-space pointer to the new cpu mask + */ +asmlinkage int sys_sched_setaffinity(pid_t pid, unsigned int len, + unsigned long *new_mask_ptr) +{ + unsigned long new_mask; + task_t *p; + int retval; + + if (len < sizeof(new_mask)) + return -EINVAL; + + if (copy_from_user(&new_mask, new_mask_ptr, sizeof(new_mask))) + return -EFAULT; + + new_mask &= cpu_online_map; + if (!new_mask) + return -EINVAL; + + read_lock(&tasklist_lock); + + p = find_process_by_pid(pid); + if (!p) { + read_unlock(&tasklist_lock); + return -ESRCH; + } + + /* + * It is not safe to call set_cpus_allowed with the + * tasklist_lock held. We will bump the task_struct's + * usage count and then drop tasklist_lock. + */ + get_task_struct(p); + read_unlock(&tasklist_lock); + + retval = -EPERM; + if ((current->euid != p->euid) && (current->euid != p->uid) && + !capable(CAP_SYS_NICE)) + goto out_unlock; + + retval = 0; + set_cpus_allowed(p, new_mask); + +out_unlock: + put_task_struct(p); + return retval; +} + +/** + * sys_sched_getaffinity - get the cpu affinity of a process + * @pid: pid of the process + * @len: length of the new mask + * @user_mask_ptr: userspace pointer to the mask + */ +asmlinkage int sys_sched_getaffinity(pid_t pid, unsigned int len, + unsigned long *user_mask_ptr) +{ + unsigned long mask; + unsigned int real_len; + task_t *p; + int retval; + + real_len = sizeof(mask); + + if (len < real_len) + return -EINVAL; + + read_lock(&tasklist_lock); + + retval = -ESRCH; + p = find_process_by_pid(pid); + if (!p) + goto out_unlock; + + retval = 0; + mask = p->cpus_allowed & cpu_online_map; + +out_unlock: + read_unlock(&tasklist_lock); + if (retval) + return retval; + if (copy_to_user(user_mask_ptr, &mask, real_len)) + return -EFAULT; + return real_len; +} + asmlinkage long sys_sched_yield(void) { runqueue_t *rq; |