On Wed, Apr 27, 2011 at 10:06 AM, KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote: >> On Wed, Apr 27, 2011 at 9:37 AM, Dave Young <hidave.darkstar@xxxxxxxxx> wrote: >> > On Wed, Apr 27, 2011 at 7:33 AM, Minchan Kim <minchan.kim@xxxxxxxxx> wrote: >> >> On Tue, Apr 26, 2011 at 6:39 PM, Dave Young <hidave.darkstar@xxxxxxxxx> wrote: >> >>> On Tue, Apr 26, 2011 at 5:28 PM, Minchan Kim <minchan.kim@xxxxxxxxx> wrote: >> >>>> Please resend this with [2/2] to linux-mm. >> >>>> >> >>>> On Tue, Apr 26, 2011 at 5:59 PM, Dave Young <hidave.darkstar@xxxxxxxxx> wrote: >> >>>>> When memory pressure is high, virtio ballooning will probably cause oom killing. >> >>>>> Even if alloc_page with GFP_NORETRY itself does not directly trigger oom it >> >>>>> will make memory becoming low then memory alloc of other processes will trigger >> >>>>> oom killing. It is not desired behaviour. >> >>>> >> >>>> I can't understand why it is undesirable. >> >>>> Why do we have to handle it specially? >> >>>> >> >>> >> >>> Suppose user run some random memory hogging process while ballooning >> >>> it will be undesirable. >> >> >> >> >> >> In VM POV, kvm and random memory hogging processes are customers. >> >> If we handle ballooning specially with disable OOM, what happens other >> >> processes requires memory at same time? Should they wait for balloon >> >> driver to release memory? >> >> >> >> I don't know your point. Sorry. >> >> Could you explain your scenario in detail for justify your idea? >> > >> > What you said make sense I understand what you said now. Lets ignore >> > my above argue and see what I'm actually doing. >> > >> > I'm hacking with balloon driver to fit to short the vm migration time. >> > >> > while migrating host tell guest to balloon as much memory as it can, then start >> > migrate, just skip the ballooned pages, after migration done tell >> > guest to release the memory. >> > >> > In migration case oom is not I want to see and disable oom will be good. >> >> BTW, if oom_killer_disabled is really not recommended to use I can >> switch back to oom_notifier way. > > Could you please explain why you dislike oom_notifier and what problem > you faced? I haven't understand why oom_notifier is bad. probably my > less knowledge of balloon is a reason. > Both is fine for me indeed, oom_killer_disable is more simple to use instead. I ever sent a oom_notifier patch last year and did not get much intention, I can refresh and resend it. -- Regards dave -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
