From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:28718 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750825AbaAXJR0 (ORCPT ); Fri, 24 Jan 2014 04:17:26 -0500 Message-ID: <52E22F5C.7050006@cn.fujitsu.com> Date: Fri, 24 Jan 2014 17:16:12 +0800 From: Wang Shilong MIME-Version: 1.0 To: bo.li.liu@oracle.com CC: linux-btrfs@vger.kernel.org Subject: Re: [PATCH] Btrfs: optimize to remove unnecessary removal with ulist reallocation References: <1389360346-23842-1-git-send-email-wangsl.fnst@cn.fujitsu.com> <20140113023109.GA26294@localhost.localdomain> In-Reply-To: <20140113023109.GA26294@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi Liu, On 01/13/2014 10:31 AM, Liu Bo wrote: > On Fri, Jan 10, 2014 at 09:25:46PM +0800, Wang Shilong wrote: >> Here we are not going to free memory, no need to remove every node >> one by one, just init root node here is ok. > Looks fine, but we need to make sure that it passes the regression test since you're > working on an old bug. Sorry for late reply, i have just sent a regression test for this. I did some hacking in kernel codes, and make sure test covers ulist reallocation, hopely it is helpful in the future.^_^ url can be seen: https://patchwork.kernel.org/patch/3533801/ Thanks, Wang > > -liubo > >> Cc: Liu Bo >> Signed-off-by: Wang Shilong >> --- >> fs/btrfs/ulist.c | 4 +--- >> 1 file changed, 1 insertion(+), 3 deletions(-) >> >> diff --git a/fs/btrfs/ulist.c b/fs/btrfs/ulist.c >> index b0a523b2..35f5de9 100644 >> --- a/fs/btrfs/ulist.c >> +++ b/fs/btrfs/ulist.c >> @@ -207,9 +207,6 @@ int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux, >> void *old = NULL; >> int i; >> >> - for (i = 0; i < ulist->nnodes; i++) >> - rb_erase(&ulist->nodes[i].rb_node, &ulist->root); >> - >> /* >> * if nodes_alloced == ULIST_SIZE no memory has been allocated >> * yet, so pass NULL to krealloc >> @@ -234,6 +231,7 @@ int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux, >> * pointers, so we have to do it ourselves. Otherwise we may >> * be bitten by crashes. >> */ >> + ulist->root = RB_ROOT; >> for (i = 0; i < ulist->nnodes; i++) { >> ret = ulist_rbtree_insert(ulist, &ulist->nodes[i]); >> if (ret < 0) >> -- >> 1.8.3.1 >>