On Tue, Dec 26, 2017 at 02:58:45PM +0800, Dave Young wrote: > On 12/26/17 at 08:26am, Bhupesh Sharma wrote: > > On Tue, Dec 26, 2017 at 7:58 AM, AKASHI Takahiro > > <takahiro.akashi@xxxxxxxxxx> wrote: > > > On Tue, Dec 26, 2017 at 09:35:17AM +0800, Dave Young wrote: > > >> [snip] > > >> > > > Well, we may be able to change pr_warn() to pr_warn_once() here, but > > >> > > > I hope that adding "numa=off" to kernel command line should also work. > > >> > > > > >> > > Hmm, adding "numa=off" to crashkernel bootargs works, and TBH it was > > >> > > my initial thought process as well, but I am not sure if this will > > >> > > cause any regressions on aarch64 systems which use crashdump feature. > > >> > > > >> > It should be fine since we use numa=off by default for all other arches > > >> > ie. x86, ppc64 and s390. Actually disabling numa in kdump kernel can save > > >> > mm component memory usage. > > >> > > > >> > > >> Forgot to say I means in RHEL and Fedora we use numa=off for kdump.. > > > > > > Thank you for the clarification. > > > (It might be better to make numa off automatically if maxcpus == 0 (and 1?).) > > > > > > > Not sure if we can leave this to the distribution-specific kdump > > scripts (as the crashkernel boot can be held up for sufficient time > > and may appear stuck). The distribution scripts may be different (for > > e.g. ubuntu and RHEL/fedora) across distributions and may have > > different bootarg options. > > Personally I think distribution should take care of this param as for > kdump. But as AKASHI said it could be a issue for 1st kernel with > nr_cpus=1 booting. Problem is why we do not see this issue on other > machines. The issue won't be kdump-specific. Theoretically, it also takes place when "mem=" is specified on numa. Since we can avoid annoying messages by adding "numa=off", I'm reluctant to suppress most of messages but the first. My suggestion here is to add some notes in Documentation/kdump/kdump.txt regarding NUMA case. Thanks, Takahiro AKASHI > > > > So how about considering a kernel fix only which doesn't require > > relying on changing the distribution-specific kdump scripts, as we > > should avoid introducing a regression while trying to fix a regression > > :) > > > > Just my 2 cents. > > > > Thanks, > > Bhupesh > > Thanks > Dave _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
