On Mon, Aug 03, 2009 at 09:26:59AM -0400, Chris Mason wrote: > On Sun, Aug 02, 2009 at 10:04:40PM -0700, Roland Dreier wrote: > > > > > Well, dont waste too much time on it (beyond the due diligence > > > level) - Andi forgot that the right way to stress-test patches is to > > > get through the review process and then through the integration > > > trees which have far more test exposure than any single contributor > > > can test. > > > > > > Patch submitters cannot possibly test every crazy possibility that > > > is out there - nor should they: it just doesnt scale. What we expect > > > people to do is to write clean patches, to test the bits on their > > > own boxes and submit them to lkml and address specific review > > > feedback. > > > > I respectfully disagree in this case. For patches that touch, say, > > something hardware dependent where the patch submitter doesn't have all > > the variations on the hardware, yes, I agree, scale the testing by > > running the code on many machines. But for the code in question, where > > some very fundamental and complex changes are being made to filesystem > > locking, I don't think that testing really scales -- after all, if there > > is some race then it's quite likely that testers will just see some rare > > filesystem corruption, which could easily waste weeks of debugging > > before the BKL/reiserfs patches were even implicated. > > Definitely, the cost of the rare bug is much higher. The good news is > that reiserfs tends to pile its races into a few spots. Most of them > can be found with a 12 hour run of the namesys stress.sh program and a > lot of memory pressure. I'd compile with preemption on and you'll have > a good test on any SMP machine. > > http://oss.oracle.com/~mason/stress.sh > > stress.sh just copies a source directory into the test filesystem, then > reads it back and deletes it in a loop. I'd run with 50 procs and > enough memory pressure for the box to lightly swap (booting w/mem= is a > fine way to make memory pressure). This way you make sure to hammer on > the metadata writeback paths, which is where all of the difficult races > come in. > > Testing with an fsx-linux process running at the same time will make > sure all of the mmap/truncate paths are working correctly as well. > > -chris Thanks a lot for this script Chris, I'm going to test with that. -- To unsubscribe from this list: send the line "unsubscribe reiserfs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
