On Fri, 2015-09-11 at 21:43 -0700, Ming Lin wrote: > 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.
I tried rawhide-20150903 boot.iso and rawhide-20150904 boot.iso. 0903 boot.iso is OK, but 0904 boot.iso just stuck at "Reached target Basic System". So I can't see the panic. http://www.minggr.net/pub/20150912/rawhide-20150904-boot.iso.png I'll run test on 32bit VM, see if I can reproduce the bug. Adam, Could you also help to confirm that commit 7140aaf is OK and commit 8ae1266 is bad? Thanks, Ming -- 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/
