On Sat, Aug 9, 2014 at 11:18 AM, Anatol Pomozov <anatol.pomozov@xxxxxxxxx> wrote: > Hi > > Another way to get more information about this problem is to use > kernel traces. Let's enable block and writeback events: > > sudo su > cd /sys/kernel/debug/tracing > echo 1 > events/writeback/enable > echo 1 > events/block/enable > echo 1 > tracing_on > cat trace_pipe > > there will some information like processid, inode... Maybe you'll see > some pattern in the writes etc.. > > In any case this problem sounds like an upstream issue and it is > better to contact them. I've emailed the btrfs list and will follow up there. I could not make head nor tail of block/writeback events, seemed similar with the problematic kernel versions and the non-problematic ones. It could be that the kernel upgrade merely exposed an underlying issue. In any case, I uploaded a print screen showing the iotop and perf top readings.... hopefully someone can understand it. https://db.tt/TSh5piq6
