Anders Aagaard
2014-Apr-05 09:02 UTC
Re: dm-crypt + btrfs preformance - long lockups during io
I should point out this as well: # hdparm -tT /dev/sda /dev/sda: Timing cached reads: 21408 MB in 1.99 seconds = 10762.26 MB/sec Timing buffered disk reads: 1156 MB in 3.00 seconds = 385.28 MB/sec # hdparm -tT /dev/mapper/sda4_crypt /dev/mapper/sda4_crypt: Timing cached reads: 21212 MB in 1.99 seconds = 10663.44 MB/sec Timing buffered disk reads: 1218 MB in 3.00 seconds = 405.66 MB/sec So it doesn't seem to be an ssd performance issue. On Sat, Apr 5, 2014 at 10:54 AM, Anders Aagaard <aagaande@gmail.com> wrote:> Hi > > I just recently repartitioned my harddrive, and in the process switched from > ext4+ecryptfs to dm-crypt and btrfs. I'm on ubuntu 14.04, using kernel > 3.14.0-031400-generic. I'm using a intel ssd, which btrfs detects (ssd mode > enabled according to dmesg). > > On IO access I'm occasionally experiencing huge hangs, I can do something as > simple as installing a small package using dpkg and get what appears to be a > 30 second complete hardlock, and then the system continuous fine. Nothing > interesting shows up in dmesg, but I tried using latencytop to figure out > what was going on. > > Target "chrome": > Opening file - 6000ms > fsync on file - 5500ms > synchronous write - 4000ms > > Target "btrfs-endio-wri" (of wihch there are 3): > wait_current_trans.isra.34 - 5800ms (for the other 2 it's 5800 and 3000ms). > > Target "kworker/u16:7)" > wait.current.trans.isra34 - 1100ms > > Target "btrfs-transaction": > sleep_on_page - 370ms > > Some info: > # btrfs subvolume list / > ID 257 gen 8282 top level 5 path @ > ID 258 gen 8282 top level 5 path @home > > # mount > /dev/mapper/sda4_crypt on /home type btrfs (rw,noatime,subvol=@home) > /dev/mapper/sda4_crypt on / type btrfs (rw,noatime,subvol=@) > > # cat /sys/block/sda/queue/scheduler > noop [deadline] cfq > > Any ideas on what could be going on here, and what I can do to fix and or > debug the problem? > > Best regards > Anders-- Weeks of coding can save you hours of planning. - http://www.codebox.no - http://code.google.com/p/aagaande/ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html