From 267ed5d8593cedd6146eabe00d270629c9cff771 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 20 Nov 2019 16:15:12 -0800 Subject: perf affinity: Add infrastructure to save/restore affinity The kernel perf subsystem has to IPI to the target CPU for many operations. On systems with many CPUs and when managing many events the overhead can be dominated by lots of IPIs. An alternative is to set up CPU affinity in the perf tool, then set up all the events for that CPU, and then move on to the next CPU. Add some affinity management infrastructure to enable such a model. Used in followon patches. Committer notes: Use zfree() in some places, add missing stdbool.h header, some minor coding style changes. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lore.kernel.org/lkml/20191121001522.180827-3-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/affinity.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 tools/perf/util/affinity.h (limited to 'tools/perf/util/affinity.h') diff --git a/tools/perf/util/affinity.h b/tools/perf/util/affinity.h new file mode 100644 index 000000000000..0ad6a18ef20c --- /dev/null +++ b/tools/perf/util/affinity.h @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef PERF_AFFINITY_H +#define PERF_AFFINITY_H 1 + +#include + +struct affinity { + unsigned long *orig_cpus; + unsigned long *sched_cpus; + bool changed; +}; + +void affinity__cleanup(struct affinity *a); +void affinity__set(struct affinity *a, int cpu); +int affinity__setup(struct affinity *a); + +#endif // PERF_AFFINITY_H -- cgit v1.2.3