Received-SPF: pass (google.com: domain of linux-kernel+bounces-193185-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
From: Namhyung Kim <namhyung@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>,
	Eduard Zingerman <eddyz87@gmail.com>,
	Song Liu <song@kernel.org>,
	Yonghong Song <yonghong.song@linux.dev>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>,
	Stanislav Fomichev <sdf@google.com>,
	Hao Luo <haoluo@google.com>,
	Jiri Olsa <jolsa@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	bpf@vger.kernel.org,
	Aleksei Shchekotikhin <alekseis@google.com>,
	Nilay Vaish <nilayvaish@google.com>
Subject: [PATCH] bpf: Allocate bpf_event_entry with node info
Date: Tue, 28 May 2024 15:36:43 -0700
Message-ID: <20240528223643.1166776-1-namhyung@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

It was reported that accessing perf_event map entry caused pretty high
LLC misses in get_map_perf_counter().  As reading perf_event is allowed
for the local CPU only, I think we can use the target CPU of the event
as hint for the allocation like in perf_event_alloc() so that the event
and the entry can be in the same node at least.

Reported-by: Aleksei Shchekotikhin <alekseis@google.com>
Reported-by: Nilay Vaish <nilayvaish@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 kernel/bpf/arraymap.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index feabc0193852..3f7718c261d7 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -1194,10 +1194,15 @@ static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
 						   struct file *map_file)
 {
 	struct bpf_event_entry *ee;
+	struct perf_event *event = perf_file->private_data;
+	int node = -1;
 
-	ee = kzalloc(sizeof(*ee), GFP_KERNEL);
+	if (event->cpu >= 0)
+		node = cpu_to_node(cpu);
+
+	ee = kzalloc_node(sizeof(*ee), GFP_KERNEL, node);
 	if (ee) {
-		ee->event = perf_file->private_data;
+		ee->event = event;
 		ee->perf_file = perf_file;
 		ee->map_file = map_file;
 	}
-- 
2.45.1.288.g0e0cd299f1-goog