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| author | Ken Chen <kenchen@google.com> | 2007-10-18 21:32:56 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-10-18 21:32:56 +0200 |
| commit | 480b9434c542ddf2833aaed3dabba71bc0b787b5 (patch) | |
| tree | 78c2638ac583cc57165ee1393ebbbbbe367f46fb /kernel/sched_stats.h | |
| parent | cc4ea79588e688ea9b1161650979a194dd709169 (diff) | |
| download | lwn-480b9434c542ddf2833aaed3dabba71bc0b787b5.tar.gz lwn-480b9434c542ddf2833aaed3dabba71bc0b787b5.zip | |
sched: reduce schedstat variable overhead a bit
schedstat is useful in investigating CPU scheduler behavior. Ideally,
I think it is beneficial to have it on all the time. However, the
cost of turning it on in production system is quite high, largely due
to number of events it collects and also due to its large memory
footprint.
Most of the fields probably don't need to be full 64-bit on 64-bit
arch. Rolling over 4 billion events will most like take a long time
and user space tool can be made to accommodate that. I'm proposing
kernel to cut back most of variable width on 64-bit system. (note,
the following patch doesn't affect 32-bit system).
Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_stats.h')
| -rw-r--r-- | kernel/sched_stats.h | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h index 1c084842c3e7..ef1a7df80ea2 100644 --- a/kernel/sched_stats.h +++ b/kernel/sched_stats.h @@ -21,7 +21,7 @@ static int show_schedstat(struct seq_file *seq, void *v) /* runqueue-specific stats */ seq_printf(seq, - "cpu%d %lu %lu %lu %lu %lu %lu %lu %lu %lu %llu %llu %lu", + "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, rq->sched_switch, rq->sched_count, rq->sched_goidle, @@ -42,8 +42,7 @@ static int show_schedstat(struct seq_file *seq, void *v) seq_printf(seq, "domain%d %s", dcount++, mask_str); for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES; itype++) { - seq_printf(seq, " %lu %lu %lu %lu %lu %lu %lu " - "%lu", + seq_printf(seq, " %u %u %u %u %u %u %u %u", sd->lb_count[itype], sd->lb_balanced[itype], sd->lb_failed[itype], @@ -53,8 +52,7 @@ static int show_schedstat(struct seq_file *seq, void *v) sd->lb_nobusyq[itype], sd->lb_nobusyg[itype]); } - seq_printf(seq, " %lu %lu %lu %lu %lu %lu %lu %lu %lu" - " %lu %lu %lu\n", + seq_printf(seq, " %u %u %u %u %u %u %u %u %u %u %u %u\n", sd->alb_count, sd->alb_failed, sd->alb_pushed, sd->sbe_count, sd->sbe_balanced, sd->sbe_pushed, sd->sbf_count, sd->sbf_balanced, sd->sbf_pushed, |