>>Does it completely hang? yes, can't ping network, and vnc console is frozen.
>>What does "perf top" show? I'll do test today . (I'm going to vacation this night,I'll try to send results before that) ----- Mail original ----- De: "Fam Zheng" <f...@redhat.com> À: "aderumier" <aderum...@odiso.com> Cc: "Stefan Hajnoczi" <stefa...@gmail.com>, "Kevin Wolf" <kw...@redhat.com>, "qemu-devel" <qemu-devel@nongnu.org>, qemu-bl...@nongnu.org Envoyé: Vendredi 10 Juillet 2015 09:13:33 Objet: Re: [Qemu-devel] [Qemu-block] [PATCH 0/3] mirror: Fix guest responsiveness during bitmap scan On Fri, 07/10 08:54, Alexandre DERUMIER wrote: > >>Thinking about this again, I doubt > >>that lengthening the duration with a hardcoded value benifits everyone; and > >>before Alexandre's reply on old server/slow disks > > With 1ms sleep, I can reproduce the hang 100% with a fast cpu (xeon e5 v3 > 3,1ghz) and source raw file on nfs. Does it completely hang? I can't reproduce this with my machine mirroring from nfs to local: the guest runs smoothly. What does "perf top" show? Fam > > > ----- Mail original ----- > De: "Fam Zheng" <f...@redhat.com> > À: "Stefan Hajnoczi" <stefa...@gmail.com> > Cc: "Kevin Wolf" <kw...@redhat.com>, "qemu-devel" <qemu-devel@nongnu.org>, > qemu-bl...@nongnu.org > Envoyé: Vendredi 10 Juillet 2015 08:43:50 > Objet: Re: [Qemu-devel] [Qemu-block] [PATCH 0/3] mirror: Fix guest > responsiveness during bitmap scan > > On Thu, 07/09 14:02, Stefan Hajnoczi wrote: > > This patch only converts the mirror block job to use the new relax > > function. The other block jobs (stream, backup, commit) are still using > > a 0 ns delay and are therefore broken. They should probably be > > converted in the same series. > > That's because they all can be perfectly mitigated by setting a reasonable > "speed" that matchs the host horsepower. Thinking about this again, I doubt > that lengthening the duration with a hardcoded value benifits everyone; and > before Alexandre's reply on old server/slow disks, I don't recall any report, > because the coroutines would already yield often enough, when waiting for IO > to > complete. So I am not sure whether they're broken in practice. > > Fam
