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 X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D982DC17447 for ; Wed, 13 Nov 2019 10:29:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5EE62245A for ; Wed, 13 Nov 2019 10:29:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="EUT6IgcA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727531AbfKMK3U (ORCPT ); Wed, 13 Nov 2019 05:29:20 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:34740 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727142AbfKMK3T (ORCPT ); Wed, 13 Nov 2019 05:29:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=9lOMg3si2Gnh6rx4vgNn+wxw0CxWPn7gmjvzvvwa478=; b=EUT6IgcAFpvhsozYa/2LIeWbbg a0G4dbYmGt9tfmNbSzSTVYMJxvrKk90q2C0S8La8DyHRSdx29ObADygyjyHRXWaLMLk1EISyho3wH Jxv2MkatS/AOU/R6CZMGO32WZHo70YoJahP8RzP9wup4rpebmubdHdzDtLqBSbonE5W+ymumCqQz6 BJoYL8EvGI4/Ykaeez4SG7fx64Ghg0gKm42oW8jnve3RPx70ej6HeFiqCd3GMR82v5C2LEL9++gh+ wzOjb6U4IyHlcEjPHMH4XYhJ7vkdNA/OEWORlTRtQJONxzrmnmtGsNWjgsvaz1XG53NYbiJKj9wE/ Xh5Bga1g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iUptg-00073l-C9; Wed, 13 Nov 2019 10:29:12 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 68ECA305DE2; Wed, 13 Nov 2019 11:28:01 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 96CED20261862; Wed, 13 Nov 2019 11:29:08 +0100 (CET) Message-Id: <20191113102855.696893455@infradead.org> User-Agent: quilt/0.65 Date: Wed, 13 Nov 2019 11:21:16 +0100 From: Peter Zijlstra To: peterz@infradead.org, mingo@kernel.org, will@kernel.org Cc: oleg@redhat.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, bigeasy@linutronix.de, juri.lelli@redhat.com, williams@redhat.com, bristot@redhat.com, longman@redhat.com, dave@stgolabs.net, jack@suse.com Subject: [PATCH 1/5] locking/percpu-rwsem, lockdep: Make percpu-rwsem use its own lockdep_map References: <20191113102115.116470462@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As preparation for replacing the embedded rwsem, give percpu-rwsem its own lockdep_map. Signed-off-by: Peter Zijlstra (Intel) --- include/linux/percpu-rwsem.h | 29 +++++++++++++++++++---------- kernel/cpu.c | 4 ++-- kernel/locking/percpu-rwsem.c | 14 +++++++++++--- kernel/locking/rwsem.c | 4 ++-- kernel/locking/rwsem.h | 2 ++ 5 files changed, 36 insertions(+), 17 deletions(-) --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -15,8 +15,17 @@ struct percpu_rw_semaphore { struct rw_semaphore rw_sem; /* slowpath */ struct rcuwait writer; /* blocked writer */ int readers_block; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif }; +#ifdef CONFIG_DEBUG_LOCK_ALLOC +#define __PERCPU_RWSEM_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }, +#else +#define __PERCPU_RWSEM_DEP_MAP_INIT(lockname) +#endif + #define __DEFINE_PERCPU_RWSEM(name, is_static) \ static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name); \ is_static struct percpu_rw_semaphore name = { \ @@ -24,7 +33,9 @@ is_static struct percpu_rw_semaphore nam .read_count = &__percpu_rwsem_rc_##name, \ .rw_sem = __RWSEM_INITIALIZER(name.rw_sem), \ .writer = __RCUWAIT_INITIALIZER(name.writer), \ + __PERCPU_RWSEM_DEP_MAP_INIT(name) \ } + #define DEFINE_PERCPU_RWSEM(name) \ __DEFINE_PERCPU_RWSEM(name, /* not static */) #define DEFINE_STATIC_PERCPU_RWSEM(name) \ @@ -37,7 +48,7 @@ static inline void percpu_down_read(stru { might_sleep(); - rwsem_acquire_read(&sem->rw_sem.dep_map, 0, 0, _RET_IP_); + rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_); preempt_disable(); /* @@ -76,13 +87,15 @@ static inline int percpu_down_read_trylo */ if (ret) - rwsem_acquire_read(&sem->rw_sem.dep_map, 0, 1, _RET_IP_); + rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_); return ret; } static inline void percpu_up_read(struct percpu_rw_semaphore *sem) { + rwsem_release(&sem->dep_map, _RET_IP_); + preempt_disable(); /* * Same as in percpu_down_read(). @@ -92,8 +105,6 @@ static inline void percpu_up_read(struct else __percpu_up_read(sem); /* Unconditional memory barrier */ preempt_enable(); - - rwsem_release(&sem->rw_sem.dep_map, _RET_IP_); } extern void percpu_down_write(struct percpu_rw_semaphore *); @@ -110,15 +121,13 @@ extern void percpu_free_rwsem(struct per __percpu_init_rwsem(sem, #sem, &rwsem_key); \ }) -#define percpu_rwsem_is_held(sem) lockdep_is_held(&(sem)->rw_sem) - -#define percpu_rwsem_assert_held(sem) \ - lockdep_assert_held(&(sem)->rw_sem) +#define percpu_rwsem_is_held(sem) lockdep_is_held(sem) +#define percpu_rwsem_assert_held(sem) lockdep_assert_held(sem) static inline void percpu_rwsem_release(struct percpu_rw_semaphore *sem, bool read, unsigned long ip) { - lock_release(&sem->rw_sem.dep_map, ip); + lock_release(&sem->dep_map, ip); #ifdef CONFIG_RWSEM_SPIN_ON_OWNER if (!read) atomic_long_set(&sem->rw_sem.owner, RWSEM_OWNER_UNKNOWN); @@ -128,7 +137,7 @@ static inline void percpu_rwsem_release( static inline void percpu_rwsem_acquire(struct percpu_rw_semaphore *sem, bool read, unsigned long ip) { - lock_acquire(&sem->rw_sem.dep_map, 0, 1, read, 1, NULL, ip); + lock_acquire(&sem->dep_map, 0, 1, read, 1, NULL, ip); #ifdef CONFIG_RWSEM_SPIN_ON_OWNER if (!read) atomic_long_set(&sem->rw_sem.owner, (long)current); --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -331,12 +331,12 @@ void lockdep_assert_cpus_held(void) static void lockdep_acquire_cpus_lock(void) { - rwsem_acquire(&cpu_hotplug_lock.rw_sem.dep_map, 0, 0, _THIS_IP_); + rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_); } static void lockdep_release_cpus_lock(void) { - rwsem_release(&cpu_hotplug_lock.rw_sem.dep_map, _THIS_IP_); + rwsem_release(&cpu_hotplug_lock.dep_map, _THIS_IP_); } /* --- a/kernel/locking/percpu-rwsem.c +++ b/kernel/locking/percpu-rwsem.c @@ -11,7 +11,7 @@ #include "rwsem.h" int __percpu_init_rwsem(struct percpu_rw_semaphore *sem, - const char *name, struct lock_class_key *rwsem_key) + const char *name, struct lock_class_key *key) { sem->read_count = alloc_percpu(int); if (unlikely(!sem->read_count)) @@ -22,6 +22,10 @@ int __percpu_init_rwsem(struct percpu_rw __init_rwsem(&sem->rw_sem, name, rwsem_key); rcuwait_init(&sem->writer); sem->readers_block = 0; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + debug_check_no_locks_freed((void *)sem, sizeof(*sem)); + lockdep_init_map(&sem->dep_map, name, key, 0); +#endif return 0; } EXPORT_SYMBOL_GPL(__percpu_init_rwsem); @@ -142,10 +146,12 @@ static bool readers_active_check(struct void percpu_down_write(struct percpu_rw_semaphore *sem) { + rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_); + /* Notify readers to take the slow path. */ rcu_sync_enter(&sem->rss); - down_write(&sem->rw_sem); + __down_write(&sem->rw_sem); /* * Notify new readers to block; up until now, and thus throughout the @@ -168,6 +174,8 @@ EXPORT_SYMBOL_GPL(percpu_down_write); void percpu_up_write(struct percpu_rw_semaphore *sem) { + rwsem_release(&sem->dep_map, _RET_IP_); + /* * Signal the writer is done, no fast path yet. * @@ -183,7 +191,7 @@ void percpu_up_write(struct percpu_rw_se /* * Release the write lock, this will allow readers back in the game. */ - up_write(&sem->rw_sem); + __up_write(&sem->rw_sem); /* * Once this completes (at least one RCU-sched grace period hence) the --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -1383,7 +1383,7 @@ static inline int __down_read_trylock(st /* * lock for writing */ -static inline void __down_write(struct rw_semaphore *sem) +inline void __down_write(struct rw_semaphore *sem) { long tmp = RWSEM_UNLOCKED_VALUE; @@ -1446,7 +1446,7 @@ inline void __up_read(struct rw_semaphor /* * unlock after writing */ -static inline void __up_write(struct rw_semaphore *sem) +inline void __up_write(struct rw_semaphore *sem) { long tmp; --- a/kernel/locking/rwsem.h +++ b/kernel/locking/rwsem.h @@ -6,5 +6,7 @@ extern void __down_read(struct rw_semaphore *sem); extern void __up_read(struct rw_semaphore *sem); +extern void __down_write(struct rw_semaphore *sem); +extern void __up_write(struct rw_semaphore *sem); #endif /* __INTERNAL_RWSEM_H */