On 08/04/2015 at 06:10 PM Jeff Moyer wrote: > Mike Snitzer <snitzer@xxxxxxxxxx> writes: > >> On Mon, Aug 03 2015 at 4:12am -0400, >> Joerg Roedel <joro@xxxxxxxxxx> wrote: >> >>> On Sun, Aug 02, 2015 at 08:48:06PM +0200, Andreas Hartmann wrote: >>>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=34b48db66e08ca1c1bc07cf305d672ac940268dc >>>>>> >>>>>> block: remove artifical max_hw_sectors cap >>> >>> Looking at the patch, it seems to me that it just uncovered a bug >>> elsewhere. It looks like an underlying driver doesn't expect the >>> big io-requests that the patch enables and does not dma-map the whole >>> target buffer, causing the IO_PAGE_FAULTs later. >> >> That patch has caused issues elsewhere too, see this 'Revert "block: >> remove artifical max_hw_sectors cap"' thread (if/when lkml.org >> cooperates): https://lkml.org/lkml/2015/7/20/572 >> >> But it could be that there is a need for a horkage fix for this specific >> hardware? something comparable to this?: >> http://git.kernel.org/linus/af34d637637eabaf49406eb35c948cd51ba262a6 >> >> We are running out of time to fix these whack-a-mole issues in 4.2 >> though. > > CC-ing linux-ide. Original dm-devel posting: > https://www.redhat.com/archives/dm-devel/2015-July/msg00178.html > > Andreas, I would be curious to know what the value of > /sys/block/sdX/queue/max_hw_sectors_kb is for the affected disks. It's always 32767. Where does this value come from? Is it empirical or is it calculated (on base of which parameters)? Devices are: 1 x Corsair Force GT (SSD) 2 x ST3000DM001-1CH166 (rotational) (WD) How can I set a higher max_sectors_kb on boot before the partitions are mounted (-> as kernel option)? Mounting the partitions here (w/ systemd) is the easiest and best way to trigger the problem! Thanks, Andreas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
