On Fri, 2007-04-27 at 01:33 -0700, Andrew Morton wrote: > On Fri, 27 Apr 2007 09:59:27 +0200 Mike Galbraith <efault@xxxxxx> wrote: > > > Greetings, > > > > As subject states, my GUI is going away for extended periods of time > > when my very full and likely highly fragmented (how to find out) > > filesystem is under heavy write load. While write is under way, if > > amarok (mp3 player) is running, no song change will occur until write is > > finished, and the GUI can go _entirely_ comatose for very long periods. > > Usually, it will come back to life after write is finished, but > > occasionally, a complete GUI restart is necessary. > > I'd be suspecting a GUI bug if a restart is necessary. Perhaps it went to > lunch for so long in the kernel that some time-based thing went bad. Yeah, there have been some KDE updates, maybe something went south. I know for sure that nothing this horrible used to happen during IO. But then when I used to regularly test IO, my disk heads didn't have to traverse nearly as much either. > Right. One possibility here is that bonnie is stuffing new dirty blocks > onto the committing transaction's ordered-data list and JBD commit is > livelocking. Only we're not supposed to be putting those blocks on that > list. > > Another livelock possibility is that bonnie is redirtying pages faster than > commit can write them out, so commit got livelocked: > > When I was doing the original port-from-2.2 I found that an application > which does > > for ( ; ; ) > pwrite(fd, "", 1, 0); > > would permanently livelock the fs. I fixed that, but it was six years ago, > and perhaps we later unfixed it. I'll try that. > It would be most interesting to try data=writeback. Seems somewhat better, but nothing close to tolerable. I still had to hot-key to a VT and kill the bonnie. > hm, fsync. > > Aside: why the heck do applications think that their data is so important > that they need to fsync it all the time. I used to run a kernel on my > laptop which had "return 0;" at the top of fsync() and fdatasync(). Most > pleasurable. I thought unkind thoughts when I saw those traces :) Thanks, -Mike - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
