Re: per-thread rusage

From: Andrew Morton
Date: Mon Apr 09 2007 - 19:54:23 EST


On Wed, 4 Apr 2007 11:10:50 -0700
William Lee Irwin III <wli@xxxxxxxxxxxxxx> wrote:

> On Wed, 4 Apr 2007 10:29:31 -0700 William Lee Irwin III <wli@xxxxxxxxxxxxxx> wrote:
> >> It is not now possible for a thread to retrieve its own rusage in
> >> isolation. Its rusage is nowhere exposed without being intermixed with
> >> that of its sibling threads. This patch adds support for an
> >> RUSAGE_THREAD who argument that returns rusage for only the desired
> >> thread.
>
> On Wed, Apr 04, 2007 at 07:48:29PM +0200, Eric Dumazet wrote:
> > Please check mm, because we now return ru_inblock and ru_oublock as well.
> > r->ru_inblock = task_io_get_inblock(p);
> > r->ru_oublock = task_io_get_oublock(p);
>
> Respun vs. 2.6.21-rc5-mm4, still untested. Also...
>
> Signed-off-by: William Irwin <bill.irwin@xxxxxxxxxx>
>
>
> -- wli
>
>
> Index: mm-2.6.21-rc5-4/include/linux/resource.h
> ===================================================================
> --- mm-2.6.21-rc5-4.orig/include/linux/resource.h 2007-04-03 23:31:19.000000000 -0700
> +++ mm-2.6.21-rc5-4/include/linux/resource.h 2007-04-04 13:08:47.000000000 -0700
> @@ -18,7 +18,8 @@
> */
> #define RUSAGE_SELF 0
> #define RUSAGE_CHILDREN (-1)
> -#define RUSAGE_BOTH (-2) /* sys_wait4() uses this */
> +#define RUSAGE_THREAD (-2)
> +#define RUSAGE_BOTH (-3) /* sys_wait4() uses this */
>
> struct rusage {
> struct timeval ru_utime; /* user time used */
> Index: mm-2.6.21-rc5-4/kernel/sys.c
> ===================================================================
> --- mm-2.6.21-rc5-4.orig/kernel/sys.c 2007-04-03 23:33:27.000000000 -0700
> +++ mm-2.6.21-rc5-4/kernel/sys.c 2007-04-04 13:11:17.000000000 -0700
> @@ -2074,6 +2074,16 @@
> }
>
> switch (who) {
> + case RUSAGE_THREAD:
> + utime = p->utime;
> + stime = p->stime;
> + r->ru_nvcsw = p->nvcsw;
> + r->ru_nivcsw = p->nivcsw;
> + r->ru_minflt = p->min_flt;
> + r->ru_majflt = p->maj_flt;
> + r->ru_inblock = task_io_get_inblock(p);
> + r->ru_oublock = task_io_get_oublock(p);
> + break;
> case RUSAGE_BOTH:
> case RUSAGE_CHILDREN:
> utime = p->signal->cutime;
> @@ -2131,7 +2141,8 @@
>
> asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
> {
> - if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
> + if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
> + who != RUSAGE_THREAD)
> return -EINVAL;
> return getrusage(current, who, ru);
> }

Seems sane. Could we please get it tested and get a full description in
place? Something which provides enough detail for the manpage maintainers.

Also, a quick comparison between Linux's RUSAGE_THREAD and $other-os's
implementations would reduce the possibility of silly, cast-in-stone
incompatabilities.



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