On Tue, 1 Apr 2014, Mike Snitzer wrote: > On Tue, Apr 01 2014 at 12:27pm -0400, > Ondrej Kozina <okozina@xxxxxxxxxx> wrote: > > > On 03/28/2014 09:11 PM, Mike Snitzer wrote: > > >From: Mikulas Patocka <mpatocka@xxxxxxxxxx> > > > > > >Submitting write bios directly in the encryption thread caused serious > > >performance degradation. On a multiprocessor machine, encryption requests > > >finish in a different order than they were submitted. Consequently, write > > >requests would be submitted in a different order and it could cause severe > > >performance degradation. > > > (...) > > > > Hi, > > > > originally I planed to post result of performance testing but > > unfortunately I crashed the test machine several times with > > <in_subject> patch applied and onward: > > > > The test set up looks following: > > > > the base is kernel-3.14-rc8 with applied "[PATCH 2/9] block: use > > kmalloc alignment for bio slab" > > > > On top of base I compiled various dm-crypt modules: > > > > <no_patch> = raw 3.14-rc8 dm-crypt module > > <no_percpu> = "[PATCH 1/9]" > > <per_bio_data> = <no_percpu> + "[PATCH 3/9]" > > <unbound> = <per_bio_data> + "[PATCH 4/9]" > > <dont_allocate_wfix> = <unbound> + "[PATCH 5/9]" + "[PATCH 6/9]" > > <remove_io_pool> = <dont_allocate_wfix> + "[PATCH 7/9]" > > <offload> = <remove_io_pool> + "[PATCH 8/9]" > > <sort> = <offload> + "[PATCH 9/9]" > > Wonder if it worthwhile to rebase to final v3.14... could this > bio_add_page/mm crash be a function of something since fixed late in the > rc cycle? ... or try it without XFS. XFS corrupts memory on I/O error (https://bugzilla.redhat.com/show_bug.cgi?id=924301), so it may be that. Can the bug be reproduced if you modify the test to use ext2, ext3 or ext4 instead of xfs? Mikulas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
