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perf/x86/amd: Cleanup Fam10h NB event constraints 

Avoid allocating the AMD NB event constraints data structure when not
needed. This gets rid of x86_max_cores usage and avoids allocating
this on AMD Core Perfctr supporting hardware (which has separate MSRs
for NB events).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: aherrmann@suse.com
Cc: Rui Huang <ray.huang@amd.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: jencce.kernel@gmail.com
Link: http://lkml.kernel.org/r/20160320124629.GY6375@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Peter Zijlstra 2016-03-25 15:52:35 +01:00 committed by Thomas Gleixner
parent ee6825c80e
commit 32b62f4468
2 changed files with 23 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
arch/x86/events/amd/core.c
View File

@ -369,7 +369,7 @@ static int amd_pmu_cpu_prepare(int cpu)
WARN_ON_ONCE(cpuc->amd_nb);
if (boot_cpu_data.x86_max_cores < 2)
if (!x86_pmu.amd_nb_constraints)
return NOTIFY_OK;
cpuc->amd_nb = amd_alloc_nb(cpu);
@ -388,7 +388,7 @@ static void amd_pmu_cpu_starting(int cpu)
cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY;
if (boot_cpu_data.x86_max_cores < 2)
if (!x86_pmu.amd_nb_constraints)
return;
nb_id = amd_get_nb_id(cpu);
@ -414,7 +414,7 @@ static void amd_pmu_cpu_dead(int cpu)
{
struct cpu_hw_events *cpuhw;
if (boot_cpu_data.x86_max_cores < 2)
if (!x86_pmu.amd_nb_constraints)
return;
cpuhw = &per_cpu(cpu_hw_events, cpu);
@ -648,6 +648,8 @@ static __initconst const struct x86_pmu amd_pmu = {
.cpu_prepare = amd_pmu_cpu_prepare,
.cpu_starting = amd_pmu_cpu_starting,
.cpu_dead = amd_pmu_cpu_dead,
.amd_nb_constraints = 1,
};
static int __init amd_core_pmu_init(void)
@ -674,6 +676,11 @@ static int __init amd_core_pmu_init(void)
x86_pmu.eventsel = MSR_F15H_PERF_CTL;
x86_pmu.perfctr = MSR_F15H_PERF_CTR;
x86_pmu.num_counters = AMD64_NUM_COUNTERS_CORE;
/*
* AMD Core perfctr has separate MSRs for the NB events, see
* the amd/uncore.c driver.
*/
x86_pmu.amd_nb_constraints = 0;
pr_cont("core perfctr, ");
return 0;
@ -693,6 +700,14 @@ __init int amd_pmu_init(void)
if (ret)
return ret;
if (num_possible_cpus() == 1) {
/*
* No point in allocating data structures to serialize
* against other CPUs, when there is only the one CPU.
*/
x86_pmu.amd_nb_constraints = 0;
}
/* Events are common for all AMDs */
memcpy(hw_cache_event_ids, amd_hw_cache_event_ids,
sizeof(hw_cache_event_ids));

5
arch/x86/events/perf_event.h
View File

@ -607,6 +607,11 @@ struct x86_pmu {
*/
atomic_t lbr_exclusive[x86_lbr_exclusive_max];
/*
* AMD bits
*/
unsigned int amd_nb_constraints : 1;
/*
* Extra registers for events
*/