From patchwork Thu May 30 16:31:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Sterba X-Patchwork-Id: 10969047 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C3FAA76 for ; Thu, 30 May 2019 16:30:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B4D6528AFF for ; Thu, 30 May 2019 16:30:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A98E028B99; Thu, 30 May 2019 16:30:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1DEEF28AFF for ; Thu, 30 May 2019 16:30:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726581AbfE3QaI (ORCPT ); Thu, 30 May 2019 12:30:08 -0400 Received: from mx2.suse.de ([195.135.220.15]:60640 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726045AbfE3QaH (ORCPT ); Thu, 30 May 2019 12:30:07 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 3FE7BAFDB for ; Thu, 30 May 2019 16:30:06 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 5C9C2DA85E; Thu, 30 May 2019 18:31:00 +0200 (CEST) From: David Sterba To: linux-btrfs@vger.kernel.org Cc: David Sterba Subject: [PATCH 1/3] btrfs: switch extent_buffer blocking_writers from atomic to int Date: Thu, 30 May 2019 18:31:00 +0200 Message-Id: X-Mailer: git-send-email 2.21.0 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The blocking_writers is either 0 or 1 and always updated under the lock, so we don't need the atomic_t semantics. Signed-off-by: David Sterba Reviewed-by: Nikolay Borisov --- fs/btrfs/extent_io.c | 2 +- fs/btrfs/extent_io.h | 2 +- fs/btrfs/locking.c | 46 +++++++++++++++++++------------------------ fs/btrfs/print-tree.c | 2 +- 4 files changed, 23 insertions(+), 29 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 2f38c10d2bfb..57b6de9df7c4 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4823,7 +4823,7 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, eb->bflags = 0; rwlock_init(&eb->lock); atomic_set(&eb->blocking_readers, 0); - atomic_set(&eb->blocking_writers, 0); + eb->blocking_writers = 0; eb->lock_nested = false; init_waitqueue_head(&eb->write_lock_wq); init_waitqueue_head(&eb->read_lock_wq); diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index aa18a16a6ed7..201da61dfc21 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -167,7 +167,7 @@ struct extent_buffer { struct rcu_head rcu_head; pid_t lock_owner; - atomic_t blocking_writers; + int blocking_writers; atomic_t blocking_readers; bool lock_nested; /* >= 0 if eb belongs to a log tree, -1 otherwise */ diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 2f6c3c7851ed..5feb01147e19 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -111,10 +111,10 @@ void btrfs_set_lock_blocking_write(struct extent_buffer *eb) */ if (eb->lock_nested && current->pid == eb->lock_owner) return; - if (atomic_read(&eb->blocking_writers) == 0) { + if (eb->blocking_writers == 0) { btrfs_assert_spinning_writers_put(eb); btrfs_assert_tree_locked(eb); - atomic_inc(&eb->blocking_writers); + eb->blocking_writers++; write_unlock(&eb->lock); } } @@ -148,12 +148,11 @@ void btrfs_clear_lock_blocking_write(struct extent_buffer *eb) */ if (eb->lock_nested && current->pid == eb->lock_owner) return; - BUG_ON(atomic_read(&eb->blocking_writers) != 1); write_lock(&eb->lock); + BUG_ON(eb->blocking_writers != 1); btrfs_assert_spinning_writers_get(eb); - /* atomic_dec_and_test implies a barrier */ - if (atomic_dec_and_test(&eb->blocking_writers)) - cond_wake_up_nomb(&eb->write_lock_wq); + if (--eb->blocking_writers == 0) + cond_wake_up(&eb->write_lock_wq); } /* @@ -167,12 +166,10 @@ void btrfs_tree_read_lock(struct extent_buffer *eb) if (trace_btrfs_tree_read_lock_enabled()) start_ns = ktime_get_ns(); again: - BUG_ON(!atomic_read(&eb->blocking_writers) && - current->pid == eb->lock_owner); - read_lock(&eb->lock); - if (atomic_read(&eb->blocking_writers) && - current->pid == eb->lock_owner) { + BUG_ON(eb->blocking_writers == 0 && + current->pid == eb->lock_owner); + if (eb->blocking_writers && current->pid == eb->lock_owner) { /* * This extent is already write-locked by our thread. We allow * an additional read lock to be added because it's for the same @@ -185,10 +182,10 @@ void btrfs_tree_read_lock(struct extent_buffer *eb) trace_btrfs_tree_read_lock(eb, start_ns); return; } - if (atomic_read(&eb->blocking_writers)) { + if (eb->blocking_writers) { read_unlock(&eb->lock); wait_event(eb->write_lock_wq, - atomic_read(&eb->blocking_writers) == 0); + eb->blocking_writers == 0); goto again; } btrfs_assert_tree_read_locks_get(eb); @@ -203,11 +200,11 @@ void btrfs_tree_read_lock(struct extent_buffer *eb) */ int btrfs_tree_read_lock_atomic(struct extent_buffer *eb) { - if (atomic_read(&eb->blocking_writers)) + if (eb->blocking_writers) return 0; read_lock(&eb->lock); - if (atomic_read(&eb->blocking_writers)) { + if (eb->blocking_writers) { read_unlock(&eb->lock); return 0; } @@ -223,13 +220,13 @@ int btrfs_tree_read_lock_atomic(struct extent_buffer *eb) */ int btrfs_try_tree_read_lock(struct extent_buffer *eb) { - if (atomic_read(&eb->blocking_writers)) + if (eb->blocking_writers) return 0; if (!read_trylock(&eb->lock)) return 0; - if (atomic_read(&eb->blocking_writers)) { + if (eb->blocking_writers) { read_unlock(&eb->lock); return 0; } @@ -245,13 +242,11 @@ int btrfs_try_tree_read_lock(struct extent_buffer *eb) */ int btrfs_try_tree_write_lock(struct extent_buffer *eb) { - if (atomic_read(&eb->blocking_writers) || - atomic_read(&eb->blocking_readers)) + if (eb->blocking_writers || atomic_read(&eb->blocking_readers)) return 0; write_lock(&eb->lock); - if (atomic_read(&eb->blocking_writers) || - atomic_read(&eb->blocking_readers)) { + if (eb->blocking_writers || atomic_read(&eb->blocking_readers)) { write_unlock(&eb->lock); return 0; } @@ -322,10 +317,9 @@ void btrfs_tree_lock(struct extent_buffer *eb) WARN_ON(eb->lock_owner == current->pid); again: wait_event(eb->read_lock_wq, atomic_read(&eb->blocking_readers) == 0); - wait_event(eb->write_lock_wq, atomic_read(&eb->blocking_writers) == 0); + wait_event(eb->write_lock_wq, eb->blocking_writers == 0); write_lock(&eb->lock); - if (atomic_read(&eb->blocking_readers) || - atomic_read(&eb->blocking_writers)) { + if (atomic_read(&eb->blocking_readers) || eb->blocking_writers) { write_unlock(&eb->lock); goto again; } @@ -340,7 +334,7 @@ void btrfs_tree_lock(struct extent_buffer *eb) */ void btrfs_tree_unlock(struct extent_buffer *eb) { - int blockers = atomic_read(&eb->blocking_writers); + int blockers = eb->blocking_writers; BUG_ON(blockers > 1); @@ -351,7 +345,7 @@ void btrfs_tree_unlock(struct extent_buffer *eb) if (blockers) { btrfs_assert_no_spinning_writers(eb); - atomic_dec(&eb->blocking_writers); + eb->blocking_writers--; /* Use the lighter barrier after atomic */ smp_mb__after_atomic(); cond_wake_up_nomb(&eb->write_lock_wq); diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c index 1141ca5fae6a..7cb4f1fbe043 100644 --- a/fs/btrfs/print-tree.c +++ b/fs/btrfs/print-tree.c @@ -155,7 +155,7 @@ static void print_eb_refs_lock(struct extent_buffer *eb) "refs %u lock (w:%d r:%d bw:%d br:%d sw:%d sr:%d) lock_owner %u current %u", atomic_read(&eb->refs), atomic_read(&eb->write_locks), atomic_read(&eb->read_locks), - atomic_read(&eb->blocking_writers), + eb->blocking_writers, atomic_read(&eb->blocking_readers), atomic_read(&eb->spinning_writers), atomic_read(&eb->spinning_readers), From patchwork Thu May 30 16:31:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Sterba X-Patchwork-Id: 10969049 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9F83576 for ; Thu, 30 May 2019 16:30:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9270228877 for ; Thu, 30 May 2019 16:30:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 86F3828BAB; Thu, 30 May 2019 16:30:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 18B5728877 for ; Thu, 30 May 2019 16:30:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726613AbfE3QaJ (ORCPT ); Thu, 30 May 2019 12:30:09 -0400 Received: from mx2.suse.de ([195.135.220.15]:60664 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726045AbfE3QaJ (ORCPT ); Thu, 30 May 2019 12:30:09 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 94CF9AFDB for ; Thu, 30 May 2019 16:30:08 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id ABC0BDA85E; Thu, 30 May 2019 18:31:02 +0200 (CEST) From: David Sterba To: linux-btrfs@vger.kernel.org Cc: David Sterba Subject: [PATCH 2/3] btrfs: switch extent_buffer spinning_writers from atomic to int Date: Thu, 30 May 2019 18:31:02 +0200 Message-Id: <6dfcb89b254ee5016edfa9816fce3487a23b446c.1559233731.git.dsterba@suse.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The spinning_writers is either 0 or 1 and always updated under the lock, so we don't need the atomic_t semantics. Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 2 +- fs/btrfs/extent_io.h | 2 +- fs/btrfs/locking.c | 10 +++++----- fs/btrfs/print-tree.c | 2 +- 4 files changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 57b6de9df7c4..71ee9e976307 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4842,7 +4842,7 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, BUG_ON(len > MAX_INLINE_EXTENT_BUFFER_SIZE); #ifdef CONFIG_BTRFS_DEBUG - atomic_set(&eb->spinning_writers, 0); + eb->spinning_writers = 0; atomic_set(&eb->spinning_readers, 0); atomic_set(&eb->read_locks, 0); atomic_set(&eb->write_locks, 0); diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 201da61dfc21..5616b96c365d 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -187,7 +187,7 @@ struct extent_buffer { wait_queue_head_t read_lock_wq; struct page *pages[INLINE_EXTENT_BUFFER_PAGES]; #ifdef CONFIG_BTRFS_DEBUG - atomic_t spinning_writers; + int spinning_writers; atomic_t spinning_readers; atomic_t read_locks; atomic_t write_locks; diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 5feb01147e19..270667627977 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -15,19 +15,19 @@ #ifdef CONFIG_BTRFS_DEBUG static void btrfs_assert_spinning_writers_get(struct extent_buffer *eb) { - WARN_ON(atomic_read(&eb->spinning_writers)); - atomic_inc(&eb->spinning_writers); + WARN_ON(eb->spinning_writers); + eb->spinning_writers++; } static void btrfs_assert_spinning_writers_put(struct extent_buffer *eb) { - WARN_ON(atomic_read(&eb->spinning_writers) != 1); - atomic_dec(&eb->spinning_writers); + WARN_ON(eb->spinning_writers != 1); + eb->spinning_writers--; } static void btrfs_assert_no_spinning_writers(struct extent_buffer *eb) { - WARN_ON(atomic_read(&eb->spinning_writers)); + WARN_ON(eb->spinning_writers); } static void btrfs_assert_spinning_readers_get(struct extent_buffer *eb) diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c index 7cb4f1fbe043..c5cc435ed39a 100644 --- a/fs/btrfs/print-tree.c +++ b/fs/btrfs/print-tree.c @@ -157,7 +157,7 @@ static void print_eb_refs_lock(struct extent_buffer *eb) atomic_read(&eb->read_locks), eb->blocking_writers, atomic_read(&eb->blocking_readers), - atomic_read(&eb->spinning_writers), + eb->spinning_writers, atomic_read(&eb->spinning_readers), eb->lock_owner, current->pid); #endif From patchwork Thu May 30 16:31:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Sterba X-Patchwork-Id: 10969051 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8D9C676 for ; Thu, 30 May 2019 16:30:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7617226255 for ; Thu, 30 May 2019 16:30:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6A75328BAB; Thu, 30 May 2019 16:30:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 09FB526255 for ; Thu, 30 May 2019 16:30:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726667AbfE3QaM (ORCPT ); Thu, 30 May 2019 12:30:12 -0400 Received: from mx2.suse.de ([195.135.220.15]:60682 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726501AbfE3QaL (ORCPT ); Thu, 30 May 2019 12:30:11 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E3AACAFDB for ; Thu, 30 May 2019 16:30:10 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 12C3BDA85E; Thu, 30 May 2019 18:31:04 +0200 (CEST) From: David Sterba To: linux-btrfs@vger.kernel.org Cc: David Sterba Subject: [PATCH 3/3] btrfs: switch extent_buffer write_locks from atomic to int Date: Thu, 30 May 2019 18:31:04 +0200 Message-Id: <6665a7f5b02d97bde4a1cadb2478bb6ba1a01cd0.1559233731.git.dsterba@suse.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The write_locks is either 0 or 1 and always updated under the lock, so we don't need the atomic_t semantics. Signed-off-by: David Sterba Reviewed-by: Nikolay Borisov --- fs/btrfs/extent_io.c | 2 +- fs/btrfs/extent_io.h | 2 +- fs/btrfs/locking.c | 6 +++--- fs/btrfs/print-tree.c | 2 +- 4 files changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 71ee9e976307..6d75d4dcf473 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4845,7 +4845,7 @@ __alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, eb->spinning_writers = 0; atomic_set(&eb->spinning_readers, 0); atomic_set(&eb->read_locks, 0); - atomic_set(&eb->write_locks, 0); + eb->write_locks = 0; #endif return eb; diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 5616b96c365d..844e595cde5b 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -190,7 +190,7 @@ struct extent_buffer { int spinning_writers; atomic_t spinning_readers; atomic_t read_locks; - atomic_t write_locks; + int write_locks; struct list_head leak_list; #endif }; diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index 270667627977..98fccce4208c 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -58,17 +58,17 @@ static void btrfs_assert_tree_read_locked(struct extent_buffer *eb) static void btrfs_assert_tree_write_locks_get(struct extent_buffer *eb) { - atomic_inc(&eb->write_locks); + eb->write_locks++; } static void btrfs_assert_tree_write_locks_put(struct extent_buffer *eb) { - atomic_dec(&eb->write_locks); + eb->write_locks--; } void btrfs_assert_tree_locked(struct extent_buffer *eb) { - BUG_ON(!atomic_read(&eb->write_locks)); + BUG_ON(!eb->write_locks); } #else diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c index c5cc435ed39a..9cb50577d982 100644 --- a/fs/btrfs/print-tree.c +++ b/fs/btrfs/print-tree.c @@ -153,7 +153,7 @@ static void print_eb_refs_lock(struct extent_buffer *eb) #ifdef CONFIG_BTRFS_DEBUG btrfs_info(eb->fs_info, "refs %u lock (w:%d r:%d bw:%d br:%d sw:%d sr:%d) lock_owner %u current %u", - atomic_read(&eb->refs), atomic_read(&eb->write_locks), + atomic_read(&eb->refs), eb->write_locks, atomic_read(&eb->read_locks), eb->blocking_writers, atomic_read(&eb->blocking_readers),