From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <544E547C.30009@kernel.dk> Date: Mon, 27 Oct 2014 08:19:40 -0600 From: Jens Axboe MIME-Version: 1.0 Subject: Re: fio rbd completions (Was: fio rbd hang for block sizes > 1M) References: <5449BBB3.7090109@catalyst.net.nz> <5449E50E.7000808@kernel.dk> <5449EEF1.1060407@catalyst.net.nz> <544A51C7.40803@gmail.com> <544A5DA6.2010709@gmail.com> <544AD67D.4030603@catalyst.net.nz> <544AEAE7.6080603@redhat.com> <544AF0D2.1050405@catalyst.net.nz> <544B0C7F.4080109@catalyst.net.nz> <544B1D50.4010101@kernel.dk> <544B2C19.7070009@catalyst.net.nz> <544BF808.2090800@kernel.dk> <544C2371.1020403@catalyst.net.nz> In-Reply-To: <544C2371.1020403@catalyst.net.nz> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit To: Mark Kirkwood , Mark Nelson , Mark Nelson , fio@vger.kernel.org Cc: "xan.peng" , "ceph-devel@vger.kernel.org" List-ID: On 10/25/2014 04:25 PM, Mark Kirkwood wrote: > On 26/10/14 08:20, Jens Axboe wrote: >> On 10/24/2014 10:50 PM, Mark Kirkwood wrote: >>> On 25/10/14 16:47, Jens Axboe wrote: >>>> >>>> Since you're running rbd tests... Mind giving this patch a go? I don't >>>> have an easy way to test it myself. It has nothing to do with this >>>> issue, it's just a potentially faster way to do the rbd completions. >>>> >>> >>> Sure - but note I'm testing this on my i7 workstation (4x osd's running >>> on 2x Crucial M550) so not exactly server grade :-) >>> >>> With that in mind, I'm seeing slightly *slower* performance with the >>> patch applied: e.g: for 128k blocks - 2 runs, 1 uncached and the next >>> cached. >> >> Yeah, that doesn't look good. Mind trying this one out? I wonder if we >> doubly wait on them - or perhaps rbd_aio_wait_for_complete() isn't >> working correctly. If you try this one, we should know more... >> >> Goal is, I want to get rid of that usleep() in getevents. >> > > Testing with v3 patch applied hangs. I did wonder if we had somehow hit > a new variant of the cache issue - so reran with it disabled in > ceph.conf. Result is the same: > > $ fio read-test.fio > rbd_thread: (g=0): rw=read, bs=128K-128K/128K-128K/128K-128K, > ioengine=rbd, iodepth=32 > fio-2.1.13-88-gb2ee7 > Starting 1 process > rbd engine: RBD version: 0.1.8 > Jobs: 1 (f=1): [R(1)] [0.1% done] [0KB/0KB/0KB /s] [0/0/0 iops] [eta > 01h:25m:15s] There were, unfortunately, still two bugs left in -v3. I just posted an updated one, please try that and see if it works for you. -- Jens Axboe