> From: Dexuan Cui > Sent: Friday, January 21, 2022 10:15 PM > To: Oliver Sang <oliver.sang@xxxxxxxxx>; Jens Axboe <axboe@xxxxxxxxx>; Yin > Fengwei <fengwei.yin@xxxxxxxxx>; linux-block@xxxxxxxxxxxxxxx > Cc: Alex Xu (Hello71) <alex_y_xu@xxxxxxxx>; ming.lei@xxxxxxxxxx; > hch@xxxxxx; Long Li <longli@xxxxxxxxxxxxx>; Michael Kelley (LINUX) > <mikelley@xxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; Li, Philip > <philip.li@xxxxxxxxx>; Rakesh Ginjupalli <Rakesh.Ginjupalli@xxxxxxxxxxxxx> > Subject: RE: RE: very low IOPS due to "block: reduce > kblockd_mod_delayed_work_on() CPU consumption" > > > From: Oliver Sang <oliver.sang@xxxxxxxxx> > > Sent: Tuesday, December 28, 2021 5:49 AM > > ... > > Hi Jens, Dexuan, > > > > On Tue, Dec 28, 2021 at 10:30:43AM +0800, Yin Fengwei wrote: > > > Hi Jens, Dexuan, > > > > > > On 12/20/2021 1:15 PM, Dexuan Cui wrote: > > > >> From: Jens Axboe <axboe@xxxxxxxxx> > > > >> Sent: Sunday, December 19, 2021 7:28 AM > > > >>> ... > > > >>> Dexuan, can you test this for your test case too? I'm going to queue > > > >>> up a revert for -rc6 just in case. > > > >> > > > >> This one should be better... > > > >> ... > > > >> Jens Axboe > > > > > > > > Hi Jens, sorry -- unluckily I lost the test environment.. :-( > > > > I pinged the user to set up the test environment again, but he's > > > > on vacation till the beginning of January. > > > > > > We hit this issue in our testing env also and will help to verify > > > your fixing patch. Thanks. > > > > as we reported in [1], we found cb2ac2912a cause big regressions in fxmark > > tests. > > "[block] cb2ac2912a: > > fxmark.ssd_f2fs_dbench_client_4_bufferedio.works/sec -66.0% regression" > > > > By applying the patch supplied by Jens Axboe in previous thread directly > > upon cb2ac2912a, we confirmed the regression could be fixed: > > ... > > > Regards > > > Yin, Fengwei > > Hi Jens, Fengwei, > I finally regained my test evnironment and tested Jens's Dec-19 patch > (see https://www.spinics.net/lists/linux-block/msg78065.html) and it > also worked fine for me, i.e. no excessive CPU utilization even with the > default dm_mod.dm_mq_queue_depth=2048. > > BTW, Jen's patch is not in the mainline yet. I tested it using the linux-block tree. > > Thanks, > -- Dexuan Hi Jens, any plan to commit your 12/19/2021 patch? It works great according to Fengwei's and my test.
