[PATCH v1] perf record: fix binding of AIO user space buffers to nodes

From: Alexey Budankov <alexey.budankov@linux.intel.com>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>, Andi Kleen <ak@linux.intel.com>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: [PATCH v1] perf record: fix binding of AIO user space buffers to nodes
Date: Thu, 12 Mar 2020 15:21:45 +0300	[thread overview]
Message-ID: <c7ea8ffe-1357-bf9e-3a89-1da1d8e9b75b@linux.intel.com> (raw)


Correct maxnode parameter value passed to mbind() syscall to be
the amount of node mask bits to analyze plus 1. Dynamically allocate
node mask memory depending on the index of node of cpu being profiled.

Fixes: c44a8b44ca9f ("perf record: Bind the AIO user space buffers to nodes")
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
---
 tools/perf/util/mmap.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c
index 3b664fa673a6..6d604cd67a95 100644
--- a/tools/perf/util/mmap.c
+++ b/tools/perf/util/mmap.c
@@ -98,20 +98,29 @@ static int perf_mmap__aio_bind(struct mmap *map, int idx, int cpu, int affinity)
 {
 	void *data;
 	size_t mmap_len;
-	unsigned long node_mask;
+	unsigned long *node_mask;
+	unsigned long node_index;
+	int err = 0;
 
 	if (affinity != PERF_AFFINITY_SYS && cpu__max_node() > 1) {
 		data = map->aio.data[idx];
 		mmap_len = mmap__mmap_len(map);
-		node_mask = 1UL << cpu__get_node(cpu);
-		if (mbind(data, mmap_len, MPOL_BIND, &node_mask, 1, 0)) {
-			pr_err("Failed to bind [%p-%p] AIO buffer to node %d: error %m\n",
-				data, data + mmap_len, cpu__get_node(cpu));
+		node_index = cpu__get_node(cpu);
+		node_mask = bitmap_alloc(node_index + 1);
+		if (!node_mask) {
+			pr_err("Failed to allocate node mask for mbind: error %m\n");
 			return -1;
 		}
+		set_bit(node_index, node_mask);
+		if (mbind(data, mmap_len, MPOL_BIND, node_mask, node_index + 1 + 1/*nr_bits + 1*/, 0)) {
+			pr_err("Failed to bind [%p-%p] AIO buffer to node %lu: error %m\n",
+				data, data + mmap_len, node_index);
+			err = -1;
+		}
+		bitmap_free(node_mask);
 	}
 
-	return 0;
+	return err;
 }
 #else /* !HAVE_LIBNUMA_SUPPORT */
 static int perf_mmap__aio_alloc(struct mmap *map, int idx)
-- 
2.24.1

