diff options
| author | Robert Love <rml@tech9.net> | 2002-05-28 05:03:31 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@home.transmeta.com> | 2002-05-28 05:03:31 -0700 |
| commit | 01bc15eda4218694be18921cd8699bcd9a8427df (patch) | |
| tree | c28463b5e29fc1a758cd1185148de0ab2c465538 /include | |
| parent | 5ff8f2bb405a6018e26560c16606d17234a6397e (diff) | |
[PATCH] O(1) count_active_tasks
This is William Irwin's algorithmically O(1) version of
count_active_tasks (which is currently O(n) for n total tasks on the
system).
I like it a lot: we become O(1) because now we count uninterruptible
tasks, so we can return (nr_uninterruptible + nr_running). It does not
introduce any overhead or hurt the case for small n, so I have no
complaints.
This copy has a small optimization over the original posting, but is
otherwise the same thing wli posted earlier. I have tested to make sure
this returns accurate results and that the kernel profile improves.
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/sched.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 743b1aea2aca..b62a724d437c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -80,6 +80,7 @@ extern unsigned long avenrun[]; /* Load averages */ extern int nr_threads; extern int last_pid; extern unsigned long nr_running(void); +extern unsigned long nr_uninterruptible(void); #include <linux/time.h> #include <linux/param.h> |