Return-Path: Received: from mail-eopbgr50102.outbound.protection.outlook.com ([40.107.5.102]:35712 "EHLO EUR03-VE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753063AbdDNOIH (ORCPT ); Fri, 14 Apr 2017 10:08:07 -0400 From: Andrey Ryabinin To: Alexander Viro , CC: Andrey Ryabinin , Konrad Rzeszutek Wilk , Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , Steve French , Matthew Wilcox , Ross Zwisler , Trond Myklebust , Anna Schumaker , Andrew Morton , Jan Kara , Jens Axboe , Johannes Weiner , Alexey Kuznetsov , Christoph Hellwig , , , , , , Subject: [PATCH 3/4] mm/truncate: bail out early from invalidate_inode_pages2_range() if mapping is empty Date: Fri, 14 Apr 2017 17:07:52 +0300 Message-ID: <20170414140753.16108-4-aryabinin@virtuozzo.com> In-Reply-To: <20170414140753.16108-1-aryabinin@virtuozzo.com> References: <20170414140753.16108-1-aryabinin@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-nfs-owner@vger.kernel.org List-ID: If mapping is empty (both ->nrpages and ->nrexceptional is zero) we can avoid pointless lookups in empty radix tree and bail out immediately after cleancache invalidation. Signed-off-by: Andrey Ryabinin --- mm/truncate.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/truncate.c b/mm/truncate.c index 6263aff..8f12b0e 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -624,6 +624,9 @@ int invalidate_inode_pages2_range(struct address_space *mapping, int did_range_unmap = 0; cleancache_invalidate_inode(mapping); + if (mapping->nrpages == 0 && mapping->nrexceptional == 0) + return 0; + pagevec_init(&pvec, 0); index = start; while (index <= end && pagevec_lookup_entries(&pvec, mapping, index, -- 2.10.2