On 08/04/2015 at 08:11 PM, Andreas Hartmann wrote: > 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! Please - no idea how to set higher max_sectors_kb before mounting of partitions? Come on! I want to test exactly this situation! Regards, Andreas -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
