[tip: perf/core] perf core: Allocate perf_event in the target node memory

From: tip-bot2 for Namhyung Kim
Date: Wed Mar 17 2021 - 08:39:37 EST


The following commit has been merged into the perf/core branch of tip:

Commit-ID: ff65338e78418e5970a7aabbabb94c46f2bb821d
Gitweb: https://git.kernel.org/tip/ff65338e78418e5970a7aabbabb94c46f2bb821d
Author: Namhyung Kim <namhyung@xxxxxxxxxx>
AuthorDate: Thu, 11 Mar 2021 20:54:13 +09:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 16 Mar 2021 21:44:43 +01:00

perf core: Allocate perf_event in the target node memory

For cpu events, it'd better allocating them in the corresponding node
memory as they would be mostly accessed by the target cpu. Although
perf tools sets the cpu affinity before calling perf_event_open, there
are places it doesn't (notably perf record) and we should consider
other external users too.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20210311115413.444407-2-namhyung@xxxxxxxxxx
---
kernel/events/core.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f526ddb..6182cb1 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11288,13 +11288,16 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
struct perf_event *event;
struct hw_perf_event *hwc;
long err = -EINVAL;
+ int node;

if ((unsigned)cpu >= nr_cpu_ids) {
if (!task || cpu != -1)
return ERR_PTR(-EINVAL);
}

- event = kmem_cache_zalloc(perf_event_cache, GFP_KERNEL);
+ node = (cpu >= 0) ? cpu_to_node(cpu) : -1;
+ event = kmem_cache_alloc_node(perf_event_cache, GFP_KERNEL | __GFP_ZERO,
+ node);
if (!event)
return ERR_PTR(-ENOMEM);