From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f176.google.com (mail-ob0-f176.google.com [209.85.214.176]) by kanga.kvack.org (Postfix) with ESMTP id F2F1B6B003C for ; Thu, 22 May 2014 23:33:46 -0400 (EDT) Received: by mail-ob0-f176.google.com with SMTP id wo20so4794547obc.35 for ; Thu, 22 May 2014 20:33:46 -0700 (PDT) Received: from g4t3427.houston.hp.com (g4t3427.houston.hp.com. [15.201.208.55]) by mx.google.com with ESMTPS id g9si2156147obt.95.2014.05.22.20.33.46 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 22 May 2014 20:33:46 -0700 (PDT) From: Davidlohr Bueso Subject: [PATCH 4/5] mm/rmap: share the i_mmap_rwsem Date: Thu, 22 May 2014 20:33:25 -0700 Message-Id: <1400816006-3083-5-git-send-email-davidlohr@hp.com> In-Reply-To: <1400816006-3083-1-git-send-email-davidlohr@hp.com> References: <1400816006-3083-1-git-send-email-davidlohr@hp.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: mingo@kernel.org, peterz@infradead.org, riel@redhat.com, mgorman@suse.de, davidlohr@hp.com, aswin@hp.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Similarly to rmap_walk_anon() and collect_procs_anon(), there is opportunity to share the lock in rmap_walk_file() and collect_procs_file() for file backed pages. Signed-off-by: Davidlohr Bueso --- include/linux/fs.h | 10 ++++++++++ mm/memory-failure.c | 4 ++-- mm/rmap.c | 4 ++-- 3 files changed, 14 insertions(+), 4 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 60a1d7d..4c2c228 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -467,6 +467,16 @@ static inline void i_mmap_unlock_write(struct address_space *mapping) up_write(&mapping->i_mmap_rwsem); } +static inline void i_mmap_lock_read(struct address_space *mapping) +{ + down_read(&mapping->i_mmap_rwsem); +} + +static inline void i_mmap_unlock_read(struct address_space *mapping) +{ + up_read(&mapping->i_mmap_rwsem); +} + /* * Might pages of this file be mapped into userspace? */ diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 1389a28..acbcd8e 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -434,7 +434,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, struct task_struct *tsk; struct address_space *mapping = page->mapping; - i_mmap_lock_write(mapping); + i_mmap_lock_read(mapping); read_lock(&tasklist_lock); for_each_process(tsk) { pgoff_t pgoff = page_pgoff(page); @@ -456,7 +456,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, } } read_unlock(&tasklist_lock); - i_mmap_unlock_write(mapping); + i_mmap_unlock_read(mapping); } /* diff --git a/mm/rmap.c b/mm/rmap.c index 9a56e4f..5841dcb 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1685,7 +1685,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc) if (!mapping) return ret; - i_mmap_lock_write(mapping); + i_mmap_lock_read(mapping); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { unsigned long address = vma_address(page, vma); @@ -1708,7 +1708,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc) ret = rwc->file_nonlinear(page, mapping, rwc->arg); done: - i_mmap_unlock_write(mapping); + i_mmap_unlock_read(mapping); return ret; } -- 1.8.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org