From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8F6916E7F1 for ; Wed, 19 Feb 2020 14:03:04 +0000 (UTC) Date: Wed, 19 Feb 2020 16:03:02 +0200 From: Petri Latvala Message-ID: <20200219140302.GW25209@platvala-desk.ger.corp.intel.com> References: <20200219121940.18247-1-petri.latvala@intel.com> <158211860207.8112.2166645472651306406@skylake-alporthouse-com> <20200219132758.GT25209@platvala-desk.ger.corp.intel.com> <158211919553.8112.12156633649709340297@skylake-alporthouse-com> <20200219134503.GU25209@platvala-desk.ger.corp.intel.com> <158211999838.8112.4489972089827888546@skylake-alporthouse-com> <158212021432.8112.8061536783320558645@skylake-alporthouse-com> <20200219135659.GV25209@platvala-desk.ger.corp.intel.com> <158212079543.8112.5314215968286633128@skylake-alporthouse-com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <158212079543.8112.5314215968286633128@skylake-alporthouse-com> Subject: Re: [igt-dev] [PATCH i-g-t] runner/resultgen: Provide output when test output is completely empty List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" To: Chris Wilson Cc: igt-dev@lists.freedesktop.org List-ID: On Wed, Feb 19, 2020 at 01:59:55PM +0000, Chris Wilson wrote: > Quoting Petri Latvala (2020-02-19 13:56:59) > > On Wed, Feb 19, 2020 at 01:50:14PM +0000, Chris Wilson wrote: > > > Quoting Chris Wilson (2020-02-19 13:46:38) > > > > Quoting Petri Latvala (2020-02-19 13:45:03) > > > > > On Wed, Feb 19, 2020 at 01:33:15PM +0000, Chris Wilson wrote: > > > > > > Quoting Petri Latvala (2020-02-19 13:27:58) > > > > > > > On Wed, Feb 19, 2020 at 01:23:22PM +0000, Chris Wilson wrote: > > > > > > > > Quoting Petri Latvala (2020-02-19 12:19:40) > > > > > > > > > If a machine is hard-hanging or otherwise rebooted at the correct > > > > > > > > > time, intermediary output files get created but nothing ever gets > > > > > > > > > written to them. That yields results that are completely empty and > > > > > > > > > hard to categorize or even sometimes detect automatically. Handle this > > > > > > > > > corner case explicitly with a custom text explaining what might have > > > > > > > > > happened to prod result analysis towards fixing the real issue instead > > > > > > > > > of wondering if test result processing is faulty. > > > > > > > > > > > > > > > > > > The race for getting empty files is easier to hit than it seems. The > > > > > > > > > files get created by the runner before calling exec(), and there's > > > > > > > > > plenty of time to hit a really hard crash. > > > > > > > > > > > > > > > > Speaking of which, it would not be terrible if igt_runner periodically > > > > > > > > called sync() everytime it decided there were new logs to preserve. > > > > > > > > We should also probably remove/reduce the writeback delay. > > > > > > > > > > > > > > > > > > > > > Does calling sync() sync more than fsyncdata()? > > > > > > > > > > > > No manual entry for fsyncdata(), fdatasync()? > > > > > > sync/fsync includes metadata, fdatasync is just contents, unless > > > > > > metadata is required for data retrieval. > > > > > > > > > > > > So for us, there really shouldn't be any difference between fdatasync > > > > > > and fsync (with the slight exception of last access timestamps). > > > > > > > > > > Then what you're asking for is already there with --sync. > > > > > > > > Do we use it? :) > > > > > > I see that fdatasync() is used on the runner's output; are they all the > > > files that are retrieved after a crash? I'd feel more comfortable with > > > sync() as we purposefully do crash the system. > > > > Yeah, any output written gets fdatasync()d immediately. > > What about dmesg? Is that pulled from the runner's logs or from syslog? > I ask because we quite frequently see lost output in dmesg.txt >From /dev/kmsg directly. Reason for the discrepancy between runner's kernel logs and dmesg.txt is beyond me. Btw I've seen the difference go both ways so it's even more confusing. -- Petri Latvala _______________________________________________ igt-dev mailing list igt-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/igt-dev