diff options
| author | Andrew Morton <akpm@osdl.org> | 2003-07-06 05:41:34 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@home.osdl.org> | 2003-07-06 05:41:34 -0700 |
| commit | d24d1d3abedcd64a9fd90e602bbd45d73b9c0de0 (patch) | |
| tree | 265485eb31094fe187996a5c0fd5150aeeea8105 | |
| parent | d029f790d8ed6d277ef47eb1e1f99cdbc3f11017 (diff) | |
[PATCH] BSD accounting speedup
From: Ingo Molnar <mingo@elte.hu>
Most distributions turn on process accounting - but even the common
'accounting is off' case is horrible SMP-scalability-wise: it accesses a
global spinlock during every sys_exit() call, which bounces like mad on SMP
(and NUMA) systems.
(i also got rid of the unused return code.)
| -rw-r--r-- | include/linux/acct.h | 2 | ||||
| -rw-r--r-- | kernel/acct.c | 29 |
2 files changed, 20 insertions, 11 deletions
diff --git a/include/linux/acct.h b/include/linux/acct.h index 0b4ae8298a0e..69389c4af8e4 100644 --- a/include/linux/acct.h +++ b/include/linux/acct.h @@ -78,7 +78,7 @@ struct acct #ifdef CONFIG_BSD_PROCESS_ACCT struct super_block; extern void acct_auto_close(struct super_block *sb); -extern int acct_process(long exitcode); +extern void acct_process(long exitcode); #else #define acct_auto_close(x) do { } while (0) #define acct_process(x) do { } while (0) diff --git a/kernel/acct.c b/kernel/acct.c index e63095525ac2..028e310bd15f 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -394,17 +394,26 @@ static void do_acct_process(long exitcode, struct file *file) /* * acct_process - now just a wrapper around do_acct_process */ -int acct_process(long exitcode) +void acct_process(long exitcode) { struct file *file = NULL; + + /* + * accelerate the common fastpath: + */ + if (!acct_globals.file) + return; + spin_lock(&acct_globals.lock); - if (acct_globals.file) { - file = acct_globals.file; - get_file(file); - spin_unlock(&acct_globals.lock); - do_acct_process(exitcode, file); - fput(file); - } else - spin_unlock(&acct_globals.lock); - return 0; + file = acct_globals.file; + if (!file) + goto out_unlock; + + get_file(file); + spin_unlock(&acct_globals.lock); + do_acct_process(exitcode, file); + fput(file); + +out_unlock: + spin_unlock(&acct_globals.lock); } |