From: Theodore Ts'o Subject: Re: OpenPosix test case mmap_11-4 fails in ext4 filesystem Date: Wed, 21 May 2014 22:45:27 -0400 Message-ID: <20140522024527.GA22059@thunk.org> References: <537C4A2F.8040402@cn.fujitsu.com> <20140521141203.GB1501@thunk.org> <20140521150619.GA5459@rei.suse.cz> <20140521185824.GB8868@thunk.org> <20140521212003.GA7493@rei.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Luk???? Czerner , Xiaoguang Wang , linux-ext4@vger.kernel.org To: chrubis@suse.cz Return-path: Received: from imap.thunk.org ([74.207.234.97]:54642 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750965AbaEVCpi (ORCPT ); Wed, 21 May 2014 22:45:38 -0400 Content-Disposition: inline In-Reply-To: <20140521212003.GA7493@rei.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, May 21, 2014 at 11:20:03PM +0200, chrubis@suse.cz wrote: > > The test in question here (mmap_11-4) is a part of the Open Posix > Testsuite that continues to live in LTP. The whole testsuite runs in > about 30 minutes and covers most of the POSIX interfaces in ~1600 > testcases. I'm pretty familiar with the PCTS (which is different from the Open Posix Testsuite), epsecially as it relates to the tty/termios interfaces. At least with the PCTS, there are a large number of the tests which are primarily issues which are implemented in the core VFS layer or in the core TTY layer. If you are a core tty implementor (as I was), the PCTS was really useful for that. If you are a serial device driver implementor, however, not all of the tests were as useful. I suspect the same would be true with file system related tests. There will be those tests which are are really useful if you are doing core VFS work, and then there are those tests which are useful if you are working on a particular file system. Separating out those tests which are most useful for developers would probably be a good thing, although obviously tere will always be a certain amount of overlap. > I guess that we can filter filesystem related syscalls quite easily. The > overlap would take more work though. In LTP we have mostly conformance > testcases and some stress testcases. I'm not much familiar with xfstests > and its coverage. Xfstests has already taken some parts of LTP. The xfstests sources has a ltp directory with the following: % ls ltp total 376 40 aio-stress.c 8 doio.h 44 fsx.c 44 iogen.c 8 rwtest.sh* 84 doio.c 68 fsstress.c 76 growfiles.c 4 Makefile Furthermore, there are a number of xfstests which run programs like fsstress and fsx using a variety of configuration options which have historically been best at stress testing file systems. So it sounds like there's quite a lot of overlap, some of it caused by xfstests grabbing bits and pieces of LTP, and part of it because people have been adding both functional and stress tests to xfstests. The question is what's the best way of dealing with the overlap. Clearly xfstests has a lot more mindshare amonst file system developers, and LTP does have that unfortunate reputation which it is still trying to overcome. :-/ Cheers, - Ted