-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Sun, 25 May 2014 12:42:32 PM kim-bt...@bluemoose.org.uk wrote:
> Any ideas of what I can do to help debug it...? Looking at that output it seems that all those blocked processes are in congestion_wait() in mm/backing-dev.c, the comments for which say: /** * congestion_wait - wait for a backing_dev to become uncongested * @sync: SYNC or ASYNC IO * @timeout: timeout in jiffies * * Waits for up to @timeout jiffies for a backing_dev (any backing_dev) to exit * write congestion. If no backing_devs are congested then just wait for the * next write to be completed. */ The blocked tasks are: kswapd0 smbd (which correlates with what you've said before) ShFolders (is this something local?) ATA-0 (I suspect a kernel process handling that device) Interestingly there are no calls to congestion_wait() in fs/btrfs so those blocked tasks are blocked accessing other filesystems. One thing that would be interesting is to see the wchan of processes blocked in device wait state when you're in that situation. Something like this should do it: ps -eo pid,user,stat,wchan:30,comm | fgrep -w D Is this system under memory pressure at the time these happen? All the best, Chris - -- Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQEVAwUBU4HjtI1yjaOTJg85AQKPYAgAlI7elWEx0YxPqABFmS3cUVIgTskxFL6/ ha7G1wxIxeqxhx1x1cLE3oKsCAhJlrwXd6cB8e0Kmu2280fCa/N9uqdJaMq+E8ha VU0K0D6lAd2lJP9L1XVI2hlAO8YEwuFpe5ebYk//1LERsZxkPVJSrIntVKvG8aCR 9fHLa9W7Pscn9oOyC2Nvh/z4FAAHu0/QWj/uuA8cOUX0FRyHrsqhhi3a+zHNJkOo vB6nfd/TWJXXDTRO6Og9ozW8InvAvpuG0NNOVSVQd10xc09qLMaP98cBBhisFji/ r3RZ0GiyW4SlYjQWhfxP9eBtZlsQD8lZMGEXHPyzlHZrJzMfjQjJvw== =h6xh -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
