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Tue, 28 Jun 2022 07:44:52 -0700 (PDT) MIME-Version: 1.0 References: <20220628095833.2579903-1-elver@google.com> <20220628095833.2579903-10-elver@google.com> In-Reply-To: <20220628095833.2579903-10-elver@google.com> From: Dmitry Vyukov Date: Tue, 28 Jun 2022 16:44:41 +0200 Message-ID: Subject: Re: [PATCH v2 09/13] locking/percpu-rwsem: Add percpu_is_write_locked() and percpu_is_read_locked() To: Marco Elver Cc: Peter Zijlstra , Frederic Weisbecker , Ingo Molnar , Thomas Gleixner , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-perf-users@vger.kernel.org, x86@kernel.org, linux-sh@vger.kernel.org, kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org On Tue, 28 Jun 2022 at 11:59, Marco Elver wrote: > > Implement simple accessors to probe percpu-rwsem's locked state: > percpu_is_write_locked(), percpu_is_read_locked(). > > Signed-off-by: Marco Elver Reviewed-by: Dmitry Vyukov > --- > v2: > * New patch. > --- > include/linux/percpu-rwsem.h | 6 ++++++ > kernel/locking/percpu-rwsem.c | 6 ++++++ > 2 files changed, 12 insertions(+) > > diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h > index 5fda40f97fe9..36b942b67b7d 100644 > --- a/include/linux/percpu-rwsem.h > +++ b/include/linux/percpu-rwsem.h > @@ -121,9 +121,15 @@ static inline void percpu_up_read(struct percpu_rw_semaphore *sem) > preempt_enable(); > } > > +extern bool percpu_is_read_locked(struct percpu_rw_semaphore *); > extern void percpu_down_write(struct percpu_rw_semaphore *); > extern void percpu_up_write(struct percpu_rw_semaphore *); > > +static inline bool percpu_is_write_locked(struct percpu_rw_semaphore *sem) > +{ > + return atomic_read(&sem->block); > +} > + > extern int __percpu_init_rwsem(struct percpu_rw_semaphore *, > const char *, struct lock_class_key *); > > diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c > index 5fe4c5495ba3..213d114fb025 100644 > --- a/kernel/locking/percpu-rwsem.c > +++ b/kernel/locking/percpu-rwsem.c > @@ -192,6 +192,12 @@ EXPORT_SYMBOL_GPL(__percpu_down_read); > __sum; \ > }) > > +bool percpu_is_read_locked(struct percpu_rw_semaphore *sem) > +{ > + return per_cpu_sum(*sem->read_count) != 0; > +} > +EXPORT_SYMBOL_GPL(percpu_is_read_locked); > + > /* > * Return true if the modular sum of the sem->read_count per-CPU variable is > * zero. If this sum is zero, then it is stable due to the fact that if any > -- > 2.37.0.rc0.161.g10f37bed90-goog > 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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A9C9BC433EF for ; Tue, 28 Jun 2022 14:45:41 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4LXS7m0H5Nz3dwt for ; Wed, 29 Jun 2022 00:45:40 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20210112 header.b=ht86O9eM; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=google.com (client-ip=2a00:1450:4864:20::230; 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charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-sh@vger.kernel.org, Peter Zijlstra , Frederic Weisbecker , x86@kernel.org, linuxppc-dev@lists.ozlabs.org, Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Alexander Shishkin , kasan-dev@googlegroups.com, Namhyung Kim , Thomas Gleixner , Jiri Olsa , Ingo Molnar Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, 28 Jun 2022 at 11:59, Marco Elver wrote: > > Implement simple accessors to probe percpu-rwsem's locked state: > percpu_is_write_locked(), percpu_is_read_locked(). > > Signed-off-by: Marco Elver Reviewed-by: Dmitry Vyukov > --- > v2: > * New patch. > --- > include/linux/percpu-rwsem.h | 6 ++++++ > kernel/locking/percpu-rwsem.c | 6 ++++++ > 2 files changed, 12 insertions(+) > > diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h > index 5fda40f97fe9..36b942b67b7d 100644 > --- a/include/linux/percpu-rwsem.h > +++ b/include/linux/percpu-rwsem.h > @@ -121,9 +121,15 @@ static inline void percpu_up_read(struct percpu_rw_semaphore *sem) > preempt_enable(); > } > > +extern bool percpu_is_read_locked(struct percpu_rw_semaphore *); > extern void percpu_down_write(struct percpu_rw_semaphore *); > extern void percpu_up_write(struct percpu_rw_semaphore *); > > +static inline bool percpu_is_write_locked(struct percpu_rw_semaphore *sem) > +{ > + return atomic_read(&sem->block); > +} > + > extern int __percpu_init_rwsem(struct percpu_rw_semaphore *, > const char *, struct lock_class_key *); > > diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c > index 5fe4c5495ba3..213d114fb025 100644 > --- a/kernel/locking/percpu-rwsem.c > +++ b/kernel/locking/percpu-rwsem.c > @@ -192,6 +192,12 @@ EXPORT_SYMBOL_GPL(__percpu_down_read); > __sum; \ > }) > > +bool percpu_is_read_locked(struct percpu_rw_semaphore *sem) > +{ > + return per_cpu_sum(*sem->read_count) != 0; > +} > +EXPORT_SYMBOL_GPL(percpu_is_read_locked); > + > /* > * Return true if the modular sum of the sem->read_count per-CPU variable is > * zero. If this sum is zero, then it is stable due to the fact that if any > -- > 2.37.0.rc0.161.g10f37bed90-goog >