On 07/26/2018 09:42 AM, Michal Hocko wrote: > On Thu 26-07-18 09:34:58, Vlastimil Babka wrote: >> On 07/26/2018 09:26 AM, Michal Hocko wrote: >>> On Thu 26-07-18 09:18:57, Vlastimil Babka wrote: >>>> On 07/25/2018 09:52 PM, Andrew Morton wrote: >>>>> (switched to email. Please respond via emailed reply-to-all, not via the >>>>> bugzilla web interface). >>>>> >>>>> On Wed, 25 Jul 2018 11:42:57 +0000 bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: >>>>> >>>>>> https://bugzilla.kernel.org/show_bug.cgi?id=200651 >>>>>> >>>>>> Bug ID: 200651 >>>>>> Summary: cgroups iptables-restor: vmalloc: allocation failure >>>>> >>>>> Thanks. Please do note the above request. >>>>> >>>>>> Product: Memory Management >>>>>> Version: 2.5 >>>>>> Kernel Version: 4.14 >>>>>> Hardware: All >>>>>> OS: Linux >>>>>> Tree: Mainline >>>>>> Status: NEW >>>>>> Severity: normal >>>>>> Priority: P1 >>>>>> Component: Other >>>>>> Assignee: akpm@xxxxxxxxxxxxxxxxxxxx >>>>>> Reporter: gnikolov@xxxxxxxxxxx >>>>>> Regression: No >>>>>> >>>>>> Created attachment 277505 >>>>>> --> https://bugzilla.kernel.org/attachment.cgi?id=277505&action=edit >>>>>> iptables save >>>>>> >>>>>> After creating large number of cgroups and under memory pressure, iptables >>>>>> command fails with following error: >>>>>> >>>>>> "iptables-restor: vmalloc: allocation failure, allocated 3047424 of 3465216 >>>>>> bytes, mode:0x14010c0(GFP_KERNEL|__GFP_NORETRY), nodemask=(null)" >>>> >>>> This is likely the kvmalloc() in xt_alloc_table_info(). Between 4.13 and >>>> 4.17 it shouldn't use __GFP_NORETRY, but looks like commit 0537250fdc6c >>>> ("netfilter: x_tables: make allocation less aggressive") was backported >>>> to 4.14. Removing __GFP_NORETRY might help here, but bring back other >>>> issues. Less than 4MB is not that much though, maybe find some "sane" >>>> limit and use __GFP_NORETRY only above that? >>> >>> I have seen the same report via http://lkml.kernel.org/r/df6f501c-8546-1f55-40b1-7e3a8f54d872@xxxxxxxxxxx >>> and the reported confirmed that kvmalloc is not a real culprit >>> http://lkml.kernel.org/r/d99a9598-808a-6968-4131-c3949b752004@xxxxxxxxxxx >> >> Hmm but that was revert of eacd86ca3b03 ("net/netfilter/x_tables.c: use >> kvmalloc() in xt_alloc_table_info()") which was the 4.13 commit that >> removed __GFP_NORETRY (there's no __GFP_NORETRY under net/netfilter in >> v4.14). I assume it was reverted on top of vanilla v4.14 as there would >> be conflict on the stable with 0537250fdc6c backport. So what should be >> tested to be sure is either vanilla v4.14 without stable backports, or >> latest v4.14.y with revert of 0537250fdc6c. > > But 0537250fdc6c simply restored the previous NORETRY behavior from > before eacd86ca3b03. So whatever causes these issues doesn't seem to be > directly related to the kvmalloc change. Or do I miss what you are > saying? I'm saying that although it's not a regression, as you say (the vmalloc() there was only for a few kernel versions called without __GFP_NORETRY), it's still possible that removing __GFP_NORETRY will fix the issue and thus we will rule out other possibilities.
