From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f176.google.com (mail-pd0-f176.google.com [209.85.192.176]) by kanga.kvack.org (Postfix) with ESMTP id 9B0F1900014 for ; Fri, 24 Oct 2014 18:06:50 -0400 (EDT) Received: by mail-pd0-f176.google.com with SMTP id ft15so229335pdb.35 for ; Fri, 24 Oct 2014 15:06:50 -0700 (PDT) Received: from homiemail-a38.g.dreamhost.com (homie.mail.dreamhost.com. [208.97.132.208]) by mx.google.com with ESMTP id fk2si5059635pdb.228.2014.10.24.15.06.49 for ; Fri, 24 Oct 2014 15:06:49 -0700 (PDT) From: Davidlohr Bueso Subject: [PATCH 04/10] mm/rmap: share the i_mmap_rwsem Date: Fri, 24 Oct 2014 15:06:14 -0700 Message-Id: <1414188380-17376-5-git-send-email-dave@stgolabs.net> In-Reply-To: <1414188380-17376-1-git-send-email-dave@stgolabs.net> References: <1414188380-17376-1-git-send-email-dave@stgolabs.net> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: hughd@google.com, riel@redhat.com, mgorman@suse.de, peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org, dbueso@suse.de, linux-mm@kvack.org, Davidlohr Bueso Similarly to the anon memory counterpart, we can share the mapping's lock ownership as the interval tree is not modified when doing doing the walk, only the file page. Signed-off-by: Davidlohr Bueso Acked-by: Rik van Riel --- include/linux/fs.h | 10 ++++++++++ mm/rmap.c | 6 +++--- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index b183792..1059be0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -465,6 +465,16 @@ 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/rmap.c b/mm/rmap.c index f234bc6..a77726f 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1674,7 +1674,8 @@ 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); @@ -1695,9 +1696,8 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc) goto done; ret = rwc->file_nonlinear(page, mapping, rwc->arg); - done: - i_mmap_unlock_write(mapping); + i_mmap_unlock_read(mapping); return ret; } -- 1.8.4.5 -- 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