Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932837Ab3GQQpC (ORCPT ); Wed, 17 Jul 2013 12:45:02 -0400 Received: from mail-wi0-f176.google.com ([209.85.212.176]:40902 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932701Ab3GQQo7 (ORCPT ); Wed, 17 Jul 2013 12:44:59 -0400 From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Steven Rostedt , "Paul E. McKenney" , Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Borislav Petkov , Li Zhong , Mike Galbraith , Kevin Hilman Subject: [PATCH 11/18] context_tracking: User/kernel broundary cross trace events Date: Wed, 17 Jul 2013 18:44:24 +0200 Message-Id: <1374079471-3129-12-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1374079471-3129-1-git-send-email-fweisbec@gmail.com> References: <1374079471-3129-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3456 Lines: 121 This can be useful to track all kernel/user round trips. And it's also helpful to debug the context tracking subsystem. Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Paul E. McKenney Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Borislav Petkov Cc: Li Zhong Cc: Mike Galbraith Cc: Kevin Hilman --- include/trace/events/context_tracking.h | 58 +++++++++++++++++++++++++++++++ kernel/context_tracking.c | 5 +++ 2 files changed, 63 insertions(+), 0 deletions(-) create mode 100644 include/trace/events/context_tracking.h diff --git a/include/trace/events/context_tracking.h b/include/trace/events/context_tracking.h new file mode 100644 index 0000000..ce8007c --- /dev/null +++ b/include/trace/events/context_tracking.h @@ -0,0 +1,58 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM context_tracking + +#if !defined(_TRACE_CONTEXT_TRACKING_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_CONTEXT_TRACKING_H + +#include + +DECLARE_EVENT_CLASS(context_tracking_user, + + TP_PROTO(int dummy), + + TP_ARGS(dummy), + + TP_STRUCT__entry( + __field( int, dummy ) + ), + + TP_fast_assign( + __entry->dummy = dummy; + ), + + TP_printk("%s", "") +); + +/** + * user_enter - called when the kernel resumes to userspace + * @dummy: dummy arg to make trace event macro happy + * + * This event occurs when the kernel resumes to userspace after + * an exception or a syscall. + */ +DEFINE_EVENT(context_tracking_user, user_enter, + + TP_PROTO(int dummy), + + TP_ARGS(dummy) +); + +/** + * user_exit - called when userspace enters the kernel + * @dummy: dummy arg to make trace event macro happy + * + * This event occurs when userspace enters the kernel through + * an exception or a syscall. + */ +DEFINE_EVENT(context_tracking_user, user_exit, + + TP_PROTO(int dummy), + + TP_ARGS(dummy) +); + + +#endif /* _TRACE_CONTEXT_TRACKING_H */ + +/* This part must be outside protection */ +#include diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 5323a5c..64195f2 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -20,6 +20,9 @@ #include #include +#define CREATE_TRACE_POINTS +#include + struct static_key context_tracking_enabled = STATIC_KEY_INIT_FALSE; DEFINE_PER_CPU(struct context_tracking, context_tracking); @@ -62,6 +65,7 @@ void context_tracking_user_enter(void) local_irq_save(flags); if ( __this_cpu_read(context_tracking.state) != IN_USER) { if (__this_cpu_read(context_tracking.active)) { + trace_user_enter(0); /* * At this stage, only low level arch entry code remains and * then we'll run in userspace. We can assume there won't be @@ -157,6 +161,7 @@ void context_tracking_user_exit(void) */ rcu_user_exit(); vtime_user_exit(current); + trace_user_exit(0); } __this_cpu_write(context_tracking.state, IN_KERNEL); } -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/