Much smaller logs so I'm attaching them. Ralf-Peter On 15.08.2016 08:01, Michal Hocko wrote:
On Mon 15-08-16 11:16:36, Vlastimil Babka wrote:On 08/15/2016 06:48 AM, Ralf-Peter Rohbeck wrote:On 02.08.2016 12:25, Ralf-Peter Rohbeck wrote: Took me a little longer than expected due to work. The failure wouldn't happen for a while and so I started a couple of scripts and let them run. When I checked today the server didn't respond on the network and sure enough it had killed everything. This is with 4.7.0 with the config based on Debian 4.7-rc7. trace_pipe got a little big (5GB) so I uploaded the logs to https://urldefense.proofpoint.com/v2/url?u=https-3A__filebin.net_box0wycfouvhl6sr_OOM-5F4.7.0.tar.bz2&d=DQIBAg&c=8S5idjlO_n28Ko3lg6lskTMwneSC-WqZ5EBTEEvDlkg&r=yGQdEpZknbtYvR0TyhkCGu-ifLklIvXIf740poRFltQ&m=TBVC4CIIUzJlmpDNapp31jIbz3Gy1M-aQ9jhrv0U56I&s=ozhbhqcuwlWiU1Cd8PZGl5-CC69-m-sNUitSYI2ry1Y&e= . before_btrfs is before the btrfs filesystems were mounted. I did run a btrfs balance because it creates IO load and I needed to balance anyway. Maybe that's what caused it?pgmigrate_success 46738962 pgmigrate_fail 135649772 compact_migrate_scanned 309726659 compact_free_scanned 9715615169 compact_isolated 229689596 compact_stall 4777 compact_fail 3068 compact_success 1709 compact_daemon_wake 207834 The migration failures are quite enormous. Very quick analysis of the trace seems to confirm that these are mostly "real", as opposed to result of failure to isolate free pages for migration targets, although the free scanner spent a lot of time:grep "nr_failed=32" -B1 trace_pipe.log | grep isolate_freepages.*nr_taken=0 | wc -l3246 So is it one of the cases where fs is unable to migrate dirty/writeback pages?It smells that way. Now we should find out why and what can we do about that. I suspect that try_to_release_page is not able to release the page for migration. Btrfs doesn't seem to have migratepage for page cache pages so it should go via fallback_migrate_page. The following diff should tell us whether this is really the case. Just open trace_pipe and see whether this path really triggered. --- diff --git a/mm/migrate.c b/mm/migrate.c index 72c09dea6526..120e2e5fcbea 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -729,8 +729,10 @@ static int fallback_migrate_page(struct address_space *mapping, * We must have no buffers or drop them. */ if (page_has_private(page) && - !try_to_release_page(page, GFP_KERNEL)) + !try_to_release_page(page, GFP_KERNEL)) { + trace_printk("try_to_release_page failed for a_ops:%pS\n", page->a_ops); return -EAGAIN; + }return migrate_page(mapping, newpage, page, mode);}
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Attachment:
OOM_4.7.0_p1.tar.bz2
Description: OOM_4.7.0_p1.tar.bz2