Re: [PATCH v3 -tip] sched: Clean unused fields from struct rq

From: Ingo Molnar
Date: Thu Mar 19 2009 - 03:50:42 EST



* Luis Henriques <henrix@xxxxxxx> wrote:

> On Wed, Mar 18, 2009 at 10:51:37PM +0000, Luis Henriques wrote:
> > Since they are used on in statistics and are always set to zero, the following
> > fields from struct rq have been removed: yld_exp_empty, yld_act_empty and
> > yld_both_empty.
> >
> > Both Sched Debug and SCHEDSTAT_VERSION versions has also been incremented since
> > ABIs have been changed.
> >
> > Signed-off-by: Luis Henriques <henrix@xxxxxxx>
> > ---
> > kernel/sched.c | 3 ---
> > kernel/sched_debug.c | 5 +----
> > kernel/sched_stats.h | 7 +++----
> > 3 files changed, 4 insertions(+), 11 deletions(-)
> >
> > diff --git a/kernel/sched.c b/kernel/sched.c
> > index 8a579e2..4469034 100644
> > --- a/kernel/sched.c
> > +++ b/kernel/sched.c
> > @@ -646,9 +646,6 @@ struct rq {
> > /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
> >
> > /* sys_sched_yield() stats */
> > - unsigned int yld_exp_empty;
> > - unsigned int yld_act_empty;
> > - unsigned int yld_both_empty;
> > unsigned int yld_count;
> >
> > /* schedule() stats */
> > diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
> > index 4daebff..467ca72 100644
> > --- a/kernel/sched_debug.c
> > +++ b/kernel/sched_debug.c
> > @@ -286,9 +286,6 @@ static void print_cpu(struct seq_file *m, int cpu)
> > #ifdef CONFIG_SCHEDSTATS
> > #define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
> >
> > - P(yld_exp_empty);
> > - P(yld_act_empty);
> > - P(yld_both_empty);
> > P(yld_count);
> >
> > P(sched_switch);
> > @@ -313,7 +310,7 @@ static int sched_debug_show(struct seq_file *m, void *v)
> > u64 now = ktime_to_ns(ktime_get());
> > int cpu;
> >
> > - SEQ_printf(m, "Sched Debug Version: v0.08, %s %.*s\n",
> > + SEQ_printf(m, "Sched Debug Version: v0.09, %s %.*s\n",
> > init_utsname()->release,
> > (int)strcspn(init_utsname()->version, " "),
> > init_utsname()->version);
> > diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
> > index a8f93dd..32d2bd4 100644
> > --- a/kernel/sched_stats.h
> > +++ b/kernel/sched_stats.h
> > @@ -4,7 +4,7 @@
> > * bump this up when changing the output format or the meaning of an existing
> > * format, so that tools can adapt (or abort)
> > */
> > -#define SCHEDSTAT_VERSION 14
> > +#define SCHEDSTAT_VERSION 15
> >
> > static int show_schedstat(struct seq_file *seq, void *v)
> > {
> > @@ -26,9 +26,8 @@ static int show_schedstat(struct seq_file *seq, void *v)
> >
> > /* runqueue-specific stats */
> > seq_printf(seq,
> > - "cpu%d %u %u %u %u %u %u %u %u %u %llu %llu %lu",
> > - cpu, rq->yld_both_empty,
> > - rq->yld_act_empty, rq->yld_exp_empty, rq->yld_count,
> > + "cpu%d %u %u %u %u %u %u %llu %llu %lu",
> > + cpu, rq->yld_count,
> > rq->sched_switch, rq->sched_count, rq->sched_goidle,
> > rq->ttwu_count, rq->ttwu_local,
> > rq->rq_cpu_time,
> > --
> > 1.6.2
>
> Btw: I tried Greg schedtop with this patch and the app behaviour is as expected:
>
> $ ./schedtop
> Exception: unsupported version

Mind updating the app too and post it here please? It's the only app
that relies on this file AFAIK.

Ingo
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