[PATCH] perf, x86: Allow setting period 1

From: Andi Kleen
Date: Fri Mar 08 2013 - 18:24:36 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

I had some requests for setting period 1, so that every event of something
is caught. To my knowledge there is no limit to 1 on Intel hardware.
Just remove the check for minimum 2

If specific CPUs have problems we can black list them.

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/perf_event.c | 5 -----
1 files changed, 0 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index bf0f01a..2b394ae 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -946,11 +946,6 @@ int x86_perf_event_set_period(struct perf_event *event)
hwc->last_period = period;
ret = 1;
}
- /*
- * Quirk: certain CPUs dont like it if just 1 hw_event is left:
- */
- if (unlikely(left < 2))
- left = 2;

if (left > x86_pmu.max_period)
left = x86_pmu.max_period;
--
1.7.7.6

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