On Sat, Dec 27, 2014 at 01:28:46PM -0500, Zygo Blaxell wrote: > On Sat, Dec 27, 2014 at 09:30:43AM +0000, Hugo Mills wrote: > > On Sat, Dec 27, 2014 at 10:01:17AM +0100, Martin Steigerwald wrote: > > > Am Freitag, 26. Dezember 2014, 14:48:38 schrieb Robert White: > > > > On 12/26/2014 05:37 AM, Martin Steigerwald wrote: > > Now, since you're seeing lockups when the space on your disks is > > all allocated I'd say that's a bug. However, you're the *only* person > > who's reported this as a regular occurrence. Does this happen with all > > filesystems you have, or just this one? > > I do see something similar, but there are so many problems going on I > have no idea which ones to report, and which ones are my own doing. :-P > > I see lots of CPU being burned when all the disk space is allocated > to chunks, but there is still lots of space free (multiple GB) inside > the chunks. > > iotop shows a crapton of disk writes (1-5MB/sec) from one kworker. > There are maybe a few kB/sec of writes through the filesystem at the time. > > The filesystem where I see this most is on a laptop, so the disk writes > also hit the CPU again for encryption. There's so much CPU usage it's > worth mentioning twice. :-( > > 'watch cat /proc/12345/stack' on the active processes shows the kernel > fairly often in that new chunk deallocator function whose name escapes > me at the moment. > > Deleting a bunch of data then running balance helps return to sane CPU > usage...for a while (maybe a week?). > > It's not technically "locked up" per se, but when a 5KB download takes > a minute or more, most users won't wait around to see the difference. > > Kernel versions I'm using are 3.17.7 and 3.18.1.
OK, so I'd like to change my statement above. When I first read Martin's problem, I thought that he was referring to a complete, hit-the-power-button kind of lock-up. Given that (erroneous) assumption, I stand by my (now pointless) statement. :) I realised during a brief conversation on IRC that Martin was actually referring to long but temporary periods where the machine is unusable by any process requiring disk activity. There's clearly a number of people seeing that. It doesn't stop it being a major problem, but it does change the interpretation considerably. Hugo. -- Hugo Mills | Mixing mathematics and alcohol is dangerous. Don't hugo@... carfax.org.uk | drink and derive. http://carfax.org.uk/ | PGP: 65E74AC0 |
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