From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: new metadata reader/writer locks in integration-test Date: Fri, 22 Jul 2011 11:49:15 -0400 Message-ID: <20110722154915.GA15194@shiny> References: <1311096438-sup-1263@shiny> <4E2638A6.2070404@jp.fujitsu.com> <1311148631-sup-9551@shiny> <4E269379.20405@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-btrfs To: Tsutomu Itoh Return-path: In-Reply-To: <4E269379.20405@jp.fujitsu.com> List-ID: On Wed, Jul 20, 2011 at 05:36:09PM +0900, Tsutomu Itoh wrote: > (2011/07/20 16:58), Chris Mason wrote: > > Excerpts from Tsutomu Itoh's message of 2011-07-19 22:08:38 -0400: > >> (2011/07/20 2:30), Chris Mason wrote: > >>> Hi everyone, > >>> > >>> I've pushed out a new integration-test branch, and it includes a new > >>> reader/writer locking scheme for the btree locks. > >>> > >>> We've seen a number of benchmarks dominated by contention on the root > >>> node lock. This changes our locks into a simple reader/writer lock. > >>> They are based on mutexes so that we still take advantage of the mutex > >>> adaptive spins for write locks (rwsemaphores were much slower). > >>> > >>> I'm also sending the individual commits, please do take a look. > >> > >> I pulled the new integration-test branch, and I got the following > >> warning messages. > >> > >> Jul 20 10:03:30 luna kernel: ------------[ cut here ]------------ > >> Jul 20 10:03:30 luna kernel: WARNING: at fs/btrfs/extent-tree.c:5704 btrfs_alloc_free_block+0x178/0x340 [btrfs]() > > > > Thanks, I think this one is related to Josef's enospc changes, but I'll > > double check. > > >What was the test? > > I ran my original test script. > This script concurrently executes the making deletion of a lot of files, > and the making deletion of a big file, etc. I'm having a hard time triggering this with Josef's current patch (after my rebase). Could you please send along the reproduction script? -chris