On Fri, Sep 11, 2015 at 2:43 PM, Mike Snitzer <snit...@redhat.com> wrote: > Ming, Jens, others: > > Please see this BZ comment that speaks to a 4.3 regression due to the > late bio splitting changes: > https://bugzilla.redhat.com/show_bug.cgi?id=1247382#c41 > > But inlined here so we can continue on list: > (In reply to Josh Boyer from comment #40) >> The function that was fixed in 4.2 doesn't exist any longer in >> 4.3.0-0.rc0.git6.1.fc24. That kernel corresponds to Linux >> v4.2-6105-gdd5cdb48edfd which contains commit >> 8ae126660fddbeebb9251a174e6fa45b6ad8f932, which removed it completely. So >> whatever fix was made in dm_merge_bvec doesn't seem to have made it to >> whatever replaced it. > > The dm core fix to dm_merge_bvec was commit bd4aaf8f9b ("dm: fix > dm_merge_bvec regression on 32 bit systems"). But I'm not sure there is > a clear equivalent in the late bio splitting code that replaced block > core's merge_bvec logic. > > merge_bvec was all about limiting bios (by asking "can/should this page > be added to this bio?") whereas the late bio splitting is more "build > the bios as large as possible and worry about splitting later". > > Regardless, this regression needs to be reported to Ming Lin > <min...@ssi.samsung.com>, Jens Axboe and the others involved in > maintaining the late bio splitting changes in block core.
I'm looking at it now. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
