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perf_counter: Always schedule all software counters in

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Software counters aren't subject to the limitations imposed by the
fixed number of hardware counter registers, so there is no reason not
to enable them all in __perf_counter_sched_in.  Previously we used to
break out of the loop when we got to a group that wouldn't fit on the
PMU; with this we continue through the list but only schedule in
software counters (or groups containing only software counters) from
there on.

Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Paul Mackerras 2009-01-12 15:11:00 +11:00
parent c0d362a832
commit dd0e6ba22e
1 changed files with 30 additions and 3 deletions
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33
kernel/perf_counter.c
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@ -455,12 +455,37 @@ group_error:
return -EAGAIN;
}
/*
* Return 1 for a software counter, 0 for a hardware counter
*/
static inline int is_software_counter(struct perf_counter *counter)
{
return !counter->hw_event.raw && counter->hw_event.type < 0;
}
/*
* Return 1 for a group consisting entirely of software counters,
* 0 if the group contains any hardware counters.
*/
static int is_software_only_group(struct perf_counter *leader)
{
struct perf_counter *counter;
if (!is_software_counter(leader))
return 0;
list_for_each_entry(counter, &leader->sibling_list, list_entry)
if (!is_software_counter(counter))
return 0;
return 1;
}
static void
__perf_counter_sched_in(struct perf_counter_context *ctx,
struct perf_cpu_context *cpuctx, int cpu)
{
struct perf_counter *counter;
u64 flags;
int can_add_hw = 1;
if (likely(!ctx->nr_counters))
return;
@ -477,10 +502,12 @@ __perf_counter_sched_in(struct perf_counter_context *ctx,
/*
* If we scheduled in a group atomically and exclusively,
* or if this group can't go on, break out:
* or if this group can't go on, don't add any more
* hardware counters.
*/
if (group_sched_in(counter, cpuctx, ctx, cpu))
break;
if (can_add_hw || is_software_only_group(counter))
if (group_sched_in(counter, cpuctx, ctx, cpu))
can_add_hw = 0;
}
hw_perf_restore(flags);
spin_unlock(&ctx->lock);