Il giorno dom, 10/11/2019 alle 06.28 +0800, Ming Lei ha scritto: > On Thu, Nov 07, 2019 at 07:59:44PM +0100, Andrea Vai wrote: > > [Sorry for the duplicate message, it didn't reach the lists due to > > html formatting] > > Il giorno gio 7 nov 2019 alle ore 08:54 Damien Le Moal > > <Damien.LeMoal@xxxxxxx> ha scritto: > > > > > > On 2019/11/07 16:04, Andrea Vai wrote: > > > > Il giorno mer, 06/11/2019 alle 22.13 +0000, Damien Le Moal ha > scritto: > > > >> > > > >> > > > >> Please simply try your write tests after doing this: > > > >> > > > >> echo mq-deadline > /sys/block/<name of your USB > > > >> disk>/queue/scheduler > > > >> > > > >> And confirm that mq-deadline is selected with: > > > >> > > > >> cat /sys/block/<name of your USB disk>/queue/scheduler > > > >> [mq-deadline] kyber bfq none > > > > > > > > ok, which kernel should I test with this: the fresh git > cloned, or the > > > > one just patched with Alan's patch, or doesn't matter which > one? > > > > > > Probably all of them to see if there are any differences. > > > > with both kernels, the output of > > cat /sys/block/sdh/queue/schedule > > > > already contains [mq-deadline]: is it correct to assume that the > echo > > command and the subsequent testing is useless? What to do now? > > Another thing we could try is to use 'none' via the following > command: > > echo none > /sys/block/sdh/queue/scheduler #suppose 'sdh' points > to the usb storage disk > > Because USB storage HBA is single hw queue, which depth is 1. This > way > should change to dispatch IO in the order of bio submission. > > Andrea, could you switch io scheduler to none and update us if > difference > can be made? Of course I would to it, but I see that with the "good" kernel the output of "cat /sys/block/sdf/queue/scheduler" (yes, now it's sdf) is noop deadline [cfq] , i.e. it doesn't show "none". Does it matter? (sorry if it's a silly question) Thanks, and bye Andrea
