From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 519CDC433EF for ; Thu, 17 Mar 2022 02:31:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354003AbiCQCdE (ORCPT ); Wed, 16 Mar 2022 22:33:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358422AbiCQCc6 (ORCPT ); Wed, 16 Mar 2022 22:32:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E8A41D318; Wed, 16 Mar 2022 19:31:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0B8A7611CB; Thu, 17 Mar 2022 02:31:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD6B9C340E9; Thu, 17 Mar 2022 02:31:39 +0000 (UTC) Date: Wed, 16 Mar 2022 22:31:38 -0400 From: Steven Rostedt To: Namhyung Kim Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , Waiman Long , Boqun Feng , LKML , Thomas Gleixner , Byungchul Park , "Paul E. McKenney" , Mathieu Desnoyers , Arnd Bergmann , Radoslaw Burny , linux-arch@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH 1/2] locking: Add lock contention tracepoints Message-ID: <20220316223138.30ceb025@gandalf.local.home> In-Reply-To: <20220316224548.500123-2-namhyung@kernel.org> References: <20220316224548.500123-1-namhyung@kernel.org> <20220316224548.500123-2-namhyung@kernel.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16 Mar 2022 15:45:47 -0700 Namhyung Kim wrote: > This adds two new lock contention tracepoints like below: > > * lock:contention_begin > * lock:contention_end > > The lock:contention_begin takes a flags argument to classify locks. I > found it useful to identify what kind of locks it's tracing like if > it's spinning or sleeping, reader-writer lock, real-time, and per-cpu. > > Move tracepoint definitions into mutex.c so that we can use them > without lockdep. > > Signed-off-by: Namhyung Kim > --- > include/trace/events/lock.h | 54 ++++++++++++++++++++++++++++++++++--- > kernel/locking/lockdep.c | 1 - > kernel/locking/mutex.c | 3 +++ > 3 files changed, 54 insertions(+), 4 deletions(-) > > diff --git a/include/trace/events/lock.h b/include/trace/events/lock.h > index d7512129a324..2a3df36d4fdb 100644 > --- a/include/trace/events/lock.h > +++ b/include/trace/events/lock.h > @@ -5,11 +5,21 @@ > #if !defined(_TRACE_LOCK_H) || defined(TRACE_HEADER_MULTI_READ) > #define _TRACE_LOCK_H > > -#include > +#include > #include > > +/* flags for lock:contention_begin */ > +#define LCB_F_SPIN (1U << 0) > +#define LCB_F_READ (1U << 1) > +#define LCB_F_WRITE (1U << 2) > +#define LCB_F_RT (1U << 3) > +#define LCB_F_PERCPU (1U << 4) > + > + > #ifdef CONFIG_LOCKDEP > > +#include > + > TRACE_EVENT(lock_acquire, > > TP_PROTO(struct lockdep_map *lock, unsigned int subclass, > @@ -78,8 +88,46 @@ DEFINE_EVENT(lock, lock_acquired, > TP_ARGS(lock, ip) > ); > > -#endif > -#endif > +#endif /* CONFIG_LOCK_STAT */ > +#endif /* CONFIG_LOCKDEP */ > + > +TRACE_EVENT(contention_begin, > + > + TP_PROTO(void *lock, unsigned int flags), > + > + TP_ARGS(lock, flags), > + > + TP_STRUCT__entry( > + __field(void *, lock_addr) > + __field(unsigned int, flags) > + ), > + > + TP_fast_assign( > + __entry->lock_addr = lock; > + __entry->flags = flags; > + ), > + > + TP_printk("%p (flags=%x)", __entry->lock_addr, __entry->flags) Perhaps make this into: TP_printk("%p (flags=%s)", __entry->lock_addr, __print_flags(__entry->flags, "|", {LCB_F_SPIN, "spin" }, {LCB_F_READ, "read" }, {LCB_F_WRITE, "write" }, {LCB_F_RT, "rt" }, {LCB_F_PERCPU, "percpu" } )) That way, the use doesn't need to figure out what the numbers mean. -- Steve > +); > + > +TRACE_EVENT(contention_end, > + > + TP_PROTO(void *lock, int ret), > + > + TP_ARGS(lock, ret), > + > + TP_STRUCT__entry( > + __field(void *, lock_addr) > + __field(int, ret) > + ), > + > + TP_fast_assign( > + __entry->lock_addr = lock; > + __entry->ret = ret; > + ), > + > + TP_printk("%p (ret=%d)", __entry->lock_addr, __entry->ret) > +); > > #endif /* _TRACE_LOCK_H */ > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index 50036c10b518..08f8fb6a2d1e 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -60,7 +60,6 @@ > > #include "lockdep_internals.h" > > -#define CREATE_TRACE_POINTS > #include > > #ifdef CONFIG_PROVE_LOCKING > diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c > index 5e3585950ec8..ee2fd7614a93 100644 > --- a/kernel/locking/mutex.c > +++ b/kernel/locking/mutex.c > @@ -30,6 +30,9 @@ > #include > #include > > +#define CREATE_TRACE_POINTS > +#include > + > #ifndef CONFIG_PREEMPT_RT > #include "mutex.h" >