Messages in this thread | | | From | Josh Don <> | Date | Thu, 29 Apr 2021 16:22:04 -0700 | Subject | Re: [PATCH 04/19] sched: Prepare for Core-wide rq->lock |
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On Thu, Apr 29, 2021 at 2:09 PM Don Hiatt <dhiatt@digitalocean.com> wrote: > > On Thu, Apr 29, 2021 at 1:48 PM Josh Don <joshdon@google.com> wrote: > > > > On Wed, Apr 28, 2021 at 9:41 AM Don Hiatt <dhiatt@digitalocean.com> wrote: > > > > > > I'm still seeing hard lockups while repeatedly setting cookies on qemu > > > processes even with > > > the updated patch. If there is any debug you'd like me to turn on, > > > just let me know. > > > > > > Thanks! > > > > > > don > > > > Thanks for the added context on your repro configuration. In addition > > to the updated patch from earlier, could you try the modification to > > double_rq_lock() from > > https://lkml.kernel.org/r/CABk29NuS-B3n4sbmavo0NDA1OCCsz6Zf2VDjjFQvAxBMQoJ_Lg@mail.gmail.com > > ? I have a feeling this is what's causing your lockup. > > > > Best, > > Josh > > Hi Josh, > > I've been running Aubrey+Peter's patch (attached) for almost 5 hours > and haven't had a single issue. :) > > I'm running a set-cookie script every 5 seconds on the two VMs (each > vm is running > 'sysbench --threads=1 --time=0 cpu run' to generate some load in the vm) and > I'm running two of the same sysbench runs on the HV while setting cookies > every 5 seconds. > > Unless I jinxed us it looks like a great fix. :) > > Let me know if there is anything else you'd like me to try. I'm going > to leave the tests running > and see what happens. I update with what I find. > > Thanks! > > don
That's awesome news, thanks for validating. Note that with Aubrey's patch there is still a race window if sched core is being enabled/disabled (ie. if you alternate between there being some cookies in the system, and no cookies). In my reply I posted an alternative version to avoid that. If your script were to do the on-off flipping with the old patch, you'd might eventually see another lockup.
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