perf evlist: Expose perf_event_mlock_kb_in_pages() helper (f5e7150c) · Commits · 戴 / test

When the user doesn't set --mmap-pages, perf_evlist__mmap() will do it by reading the maximum possible for a non-root user from the /proc/sys/kernel/perf_event_mlock_kb file. Expose that function so that 'perf trace' can, for root users, to bump mmap-pages to a higher value for root, based on the contents of this proc file. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-xay69plylwibpb3l4isrpl1k@git.kernel.org Signed-off-by:

Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evlist.c

+25 −17

Original line number	Diff line number	Diff line
		@@ -986,9 +986,9 @@ out_unmap:
		return -1;
		}

		static size_t perf_evlist__mmap_size(unsigned long pages)
		unsigned long perf_event_mlock_kb_in_pages(void)
		{
		if (pages == UINT_MAX) {
		unsigned long pages;
		int max;

		if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) {
		@@ -1005,7 +1005,15 @@ static size_t perf_evlist__mmap_size(unsigned long pages)
		pages = (max * 1024) / page_size;
		if (!is_power_of_2(pages))
		pages = rounddown_pow_of_two(pages);
		} else if (!is_power_of_2(pages))

		return pages;
		}

		static size_t perf_evlist__mmap_size(unsigned long pages)
		{
		if (pages == UINT_MAX)
		pages = perf_event_mlock_kb_in_pages();
		else if (!is_power_of_2(pages))
		return 0;

		return (pages + 1) * page_size;

tools/perf/util/evlist.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -158,6 +158,8 @@ int perf_evlist__parse_mmap_pages(const struct option *opt,
		const char *str,
		int unset);

		unsigned long perf_event_mlock_kb_in_pages(void);

		int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages,
		bool overwrite, unsigned int auxtrace_pages,
		bool auxtrace_overwrite);

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