From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751812Ab3LJU1s (ORCPT ); Tue, 10 Dec 2013 15:27:48 -0500 Received: from mail-pb0-f54.google.com ([209.85.160.54]:45719 "EHLO mail-pb0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751130Ab3LJU1q (ORCPT ); Tue, 10 Dec 2013 15:27:46 -0500 From: David Ahern To: linux-kernel@vger.kernel.org Cc: David Ahern , Pawel Moll , Ingo Molnar , Frederic Weisbecker , Peter Zijlstra , Arnaldo Carvalho de Melo , Mike Galbraith , Jiri Olsa , Namhyung Kim , Stephane Eranian , John Stultz , Sonny Rao , Thomas Gleixner Subject: [PATCH] perf: POSIX CLOCK_PERF to report current time value Date: Tue, 10 Dec 2013 13:27:39 -0700 Message-Id: <1386707259-21725-1-git-send-email-dsahern@gmail.com> X-Mailer: git-send-email 1.8.3.4 (Apple Git-47) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pawel Moll To co-relate user space events with the perf events stream a current (as in: "what time(stamp) is it now?") time value must be made available. This patch adds a POSIX clock returning the perf_clock() value and accesible from userspace: #include struct timespec ts; clock_gettime(CLOCK_PERF, &ts); Updated to 3.13 Signed-off-by: Pawel Moll Signed-off-by: David Ahern Cc: Ingo Molnar Cc: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Mike Galbraith Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Cc: John Stultz Cc: Sonny Rao Cc: Thomas Gleixner --- include/uapi/linux/time.h | 1 + kernel/events/core.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/include/uapi/linux/time.h b/include/uapi/linux/time.h index e75e1b6ff27f..b07f07914a13 100644 --- a/include/uapi/linux/time.h +++ b/include/uapi/linux/time.h @@ -56,6 +56,7 @@ struct itimerval { #define CLOCK_BOOTTIME_ALARM 9 #define CLOCK_SGI_CYCLE 10 /* Hardware specific */ #define CLOCK_TAI 11 +#define CLOCK_PERF 12 #define MAX_CLOCKS 16 #define CLOCKS_MASK (CLOCK_REALTIME | CLOCK_MONOTONIC) diff --git a/kernel/events/core.c b/kernel/events/core.c index 72348dc192c1..87aa36ac68f7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -39,6 +39,7 @@ #include #include #include +#include #include "internal.h" @@ -295,6 +296,19 @@ static inline u64 perf_clock(void) return local_clock(); } +static int perf_posix_clock_getres(const clockid_t which_clock, + struct timespec *tp) +{ + *tp = ns_to_timespec(TICK_NSEC); + return 0; +} + +static int perf_posix_clock_get(clockid_t which_clock, struct timespec *tp) +{ + *tp = ns_to_timespec(perf_clock()); + return 0; +} + static inline struct perf_cpu_context * __get_cpu_context(struct perf_event_context *ctx) { @@ -7904,6 +7918,10 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) void __init perf_event_init(void) { + struct k_clock perf_posix_clock = { + .clock_getres = perf_posix_clock_getres, + .clock_get = perf_posix_clock_get, + }; int ret; idr_init(&pmu_idr); @@ -7920,6 +7938,8 @@ void __init perf_event_init(void) ret = init_hw_breakpoint(); WARN(ret, "hw_breakpoint initialization failed with: %d", ret); + posix_timers_register_clock(CLOCK_PERF, &perf_posix_clock); + /* do not patch jump label more than once per second */ jump_label_rate_limit(&perf_sched_events, HZ); -- 1.8.3.4 (Apple Git-47)