From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]:58012 "EHLO ipmail06.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162620AbeCAWfI (ORCPT ); Thu, 1 Mar 2018 17:35:08 -0500 From: Dave Chinner To: linux-fsdevel@vger.kernel.org Cc: linux-xfs@vger.kernel.org Subject: [PATCH] inode: don't memset the inode address space twice Date: Fri, 2 Mar 2018 09:34:02 +1100 Message-Id: <20180301223402.26897-1-david@fromorbit.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Dave Chinner Noticed when looking at why cycling 600k inodes/s through the inode cache was taking a total of 8% cpu in memset() during inode initialisation. There is no need to zero the inode.i_data structure twice. This increases single threaded bulkstat throughput from ~200,000 inodes/s to ~220,000 inodes/s, so we save a substantial amount of CPU time per inode init by doing this. Signed-Off-By: Dave Chinner --- fs/inode.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index 6295f1415761..b153aeaa61ea 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -346,9 +346,8 @@ void inc_nlink(struct inode *inode) } EXPORT_SYMBOL(inc_nlink); -void address_space_init_once(struct address_space *mapping) +static void __address_space_init_once(struct address_space *mapping) { - memset(mapping, 0, sizeof(*mapping)); INIT_RADIX_TREE(&mapping->page_tree, GFP_ATOMIC | __GFP_ACCOUNT); spin_lock_init(&mapping->tree_lock); init_rwsem(&mapping->i_mmap_rwsem); @@ -356,6 +355,12 @@ void address_space_init_once(struct address_space *mapping) spin_lock_init(&mapping->private_lock); mapping->i_mmap = RB_ROOT_CACHED; } + +void address_space_init_once(struct address_space *mapping) +{ + memset(mapping, 0, sizeof(*mapping)); + __address_space_init_once(mapping); +} EXPORT_SYMBOL(address_space_init_once); /* @@ -371,7 +376,7 @@ void inode_init_once(struct inode *inode) INIT_LIST_HEAD(&inode->i_io_list); INIT_LIST_HEAD(&inode->i_wb_list); INIT_LIST_HEAD(&inode->i_lru); - address_space_init_once(&inode->i_data); + __address_space_init_once(&inode->i_data); i_size_ordered_init(inode); } EXPORT_SYMBOL(inode_init_once); -- 2.16.1