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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /tools/perf/util/smt.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/util/smt.c')
-rw-r--r--tools/perf/util/smt.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/tools/perf/util/smt.c b/tools/perf/util/smt.c
new file mode 100644
index 000000000..994e9e418
--- /dev/null
+++ b/tools/perf/util/smt.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <string.h>
+#include "api/fs/fs.h"
+#include "cputopo.h"
+#include "smt.h"
+
+bool smt_on(const struct cpu_topology *topology)
+{
+ static bool cached;
+ static bool cached_result;
+ int fs_value;
+
+ if (cached)
+ return cached_result;
+
+ if (sysfs__read_int("devices/system/cpu/smt/active", &fs_value) >= 0)
+ cached_result = (fs_value == 1);
+ else
+ cached_result = cpu_topology__smt_on(topology);
+
+ cached = true;
+ return cached_result;
+}
+
+bool core_wide(bool system_wide, const char *user_requested_cpu_list,
+ const struct cpu_topology *topology)
+{
+ /* If not everything running on a core is being recorded then we can't use core_wide. */
+ if (!system_wide)
+ return false;
+
+ /* Cheap case that SMT is disabled and therefore we're inherently core_wide. */
+ if (!smt_on(topology))
+ return true;
+
+ return cpu_topology__core_wide(topology, user_requested_cpu_list);
+}