From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [merged] fput-turn-list_head-delayed_fput_list-into-llist_head.patch removed from -mm tree Date: Mon, 15 Jul 2013 13:49:35 -0700 Message-ID: <51e4605f.ngaCk8xgpYnLHsma%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49293 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753484Ab3GOUtg (ORCPT ); Mon, 15 Jul 2013 16:49:36 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org, ying.huang@intel.com, viro@zeniv.linux.org.uk, ebiederm@xmission.com, dhowells@redhat.com, avagin@openvz.org, akpm@linux-foundation.org, a.p.zijlstra@chello.nl, oleg@redhat.com Subject: [merged] fput-turn-list_head-delayed_fput_list-into-llist_head.patch removed from -mm tree To: oleg@redhat.com,a.p.zijlstra@chello.nl,akpm@linux-foundation.org,avagin@openvz.org,dhowells@redhat.com,ebiederm@xmission.com,viro@zeniv.linux.org.uk,ying.huang@intel.com,mm-commits@vger.kernel.org From: akpm@linux-foundation.org Date: Mon, 15 Jul 2013 13:49:35 -0700 The patch titled Subject: fput: turn "list_head delayed_fput_list" into llist_head has been removed from the -mm tree. Its filename was fput-turn-list_head-delayed_fput_list-into-llist_head.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Oleg Nesterov Subject: fput: turn "list_head delayed_fput_list" into llist_head fput() and delayed_fput() can use llist and avoid the locking. This is unlikely path, it is not that this change can improve the performance, but this way the code looks simpler. Signed-off-by: Oleg Nesterov Suggested-by: Andrew Morton Cc: Al Viro Cc: Andrey Vagin Cc: "Eric W. Biederman" Cc: David Howells Cc: Huang Ying Cc: Peter Zijlstra Signed-off-by: Andrew Morton --- fs/file_table.c | 25 ++++++++++--------------- include/linux/fs.h | 2 ++ 2 files changed, 12 insertions(+), 15 deletions(-) diff -puN fs/file_table.c~fput-turn-list_head-delayed_fput_list-into-llist_head fs/file_table.c --- a/fs/file_table.c~fput-turn-list_head-delayed_fput_list-into-llist_head +++ a/fs/file_table.c @@ -265,18 +265,15 @@ static void __fput(struct file *file) mntput(mnt); } -static DEFINE_SPINLOCK(delayed_fput_lock); -static LIST_HEAD(delayed_fput_list); +static LLIST_HEAD(delayed_fput_list); static void delayed_fput(struct work_struct *unused) { - LIST_HEAD(head); - spin_lock_irq(&delayed_fput_lock); - list_splice_init(&delayed_fput_list, &head); - spin_unlock_irq(&delayed_fput_lock); - while (!list_empty(&head)) { - struct file *f = list_first_entry(&head, struct file, f_u.fu_list); - list_del_init(&f->f_u.fu_list); - __fput(f); + struct llist_node *node = llist_del_all(&delayed_fput_list); + struct llist_node *next; + + for (; node; node = next) { + next = llist_next(node); + __fput(llist_entry(node, struct file, f_u.fu_llist)); } } @@ -306,7 +303,6 @@ void fput(struct file *file) { if (atomic_long_dec_and_test(&file->f_count)) { struct task_struct *task = current; - unsigned long flags; file_sb_list_del(file); if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) { @@ -320,10 +316,9 @@ void fput(struct file *file) * fput to avoid leaking *file. */ } - spin_lock_irqsave(&delayed_fput_lock, flags); - list_add(&file->f_u.fu_list, &delayed_fput_list); - schedule_work(&delayed_fput_work); - spin_unlock_irqrestore(&delayed_fput_lock, flags); + + if (llist_add(&file->f_u.fu_llist, &delayed_fput_list)) + schedule_work(&delayed_fput_work); } } diff -puN include/linux/fs.h~fput-turn-list_head-delayed_fput_list-into-llist_head include/linux/fs.h --- a/include/linux/fs.h~fput-turn-list_head-delayed_fput_list-into-llist_head +++ a/include/linux/fs.h @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -767,6 +768,7 @@ struct file { */ union { struct list_head fu_list; + struct llist_node fu_llist; struct rcu_head fu_rcuhead; } f_u; struct path f_path; _ Patches currently in -mm which might be from oleg@redhat.com are mm-mempolicy-fix-mbind_range-vma_adjust-interaction.patch include-linux-schedh-dont-use-task-pid-tgid-in-same_thread_group-has_group_leader_pid.patch lockdep-introduce-lock_acquire_exclusive-shared-helper-macros.patch lglock-update-lockdep-annotations-to-report-recursive-local-locks.patch mm-mempolicy-turn-vma_set_policy-into-vma_dup_policy.patch kernel-wide-fix-missing-validations-on-__get-__put-__copy_to-__copy_from_user.patch autofs4-allow-autofs-to-work-outside-the-initial-pid-namespace.patch autofs4-translate-pids-to-the-right-namespace-for-the-daemon.patch signals-eventpoll-set-saved_sigmask-at-the-start.patch move-exit_task_namespaces-outside-of-exit_notify-fix.patch