lkml.org 
[lkml]   [2021]   [Nov]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] perf/x86/amd: Use faster rdpmc instruction when waiting for overflow
Date
The relatively new amd_pmu_wait_on_overflow uses rdmsr.
Update it to use the faster rdpmc instruction.

Signed-off-by: Kim Phillips <kim.phillips@amd.com>
---
arch/x86/events/amd/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 9687a8aef01c..c36cb0c6f9e1 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -587,6 +587,8 @@ static void amd_pmu_cpu_dead(int cpu)

static void amd_pmu_wait_on_overflow(int idx)
{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct hw_perf_event *hwc = &cpuc->events[idx]->hw;
unsigned int i;
u64 counter;

@@ -596,7 +598,7 @@ static void amd_pmu_wait_on_overflow(int idx)
* forever...
*/
for (i = 0; i < OVERFLOW_WAIT_COUNT; i++) {
- rdmsrl(x86_pmu_event_addr(idx), counter);
+ rdpmcl(hwc->event_base_rdpmc, counter);
if (counter & (1ULL << (x86_pmu.cntval_bits - 1)))
break;

--
2.32.0
\
 
 \ /
  Last update: 2021-11-16 18:09    [W:0.064 / U:0.900 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site