On Wed 13-07-16 13:10:06, Michal Hocko wrote: > On Tue 12-07-16 19:44:11, Mikulas Patocka wrote: [...] > > As long as swapping is in progress, the free memory is below the limit > > (because the swapping activity itself consumes any memory over the limit). > > And that triggered the OOM killer prematurely. > > I am not sure I understand the last part. Are you saing that we trigger > OOM because the initiated swapout will not be able to finish the IO thus > release the page in time? > > The oom detection checks waits for an ongoing writeout if there is no > reclaim progress and at least half of the reclaimable memory is either > dirty or under writeback. Pages under swaout are marked as under > writeback AFAIR. The writeout path (dm-crypt worker in this case) should > be able to allocate a memory from the mempool, hand over to the crypt > layer and finish the IO. Is it possible this might take a lot of time? I am not familiar with the crypto API but from what I understood from crypt_convert the encryption is done asynchronously. Then I got lost in the indirection. Who is completing the request and from what kind of context? Is it possible it wouldn't be runable for a long time? -- Michal Hocko SUSE Labs -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
