On Wed, 7 Nov 2018 11:18:29 +0100 Michal Hocko <[email protected]> wrote:
> From: Michal Hocko <[email protected]> > > The memory offlining failure reporting is inconsistent and insufficient. > Some error paths simply do not report the failure to the log at all. > When we do report there are no details about the reason of the failure > and there are several of them which makes memory offlining failures > hard to debug. > > Make sure that the > memory offlining [mem %#010llx-%#010llx] failed > message is printed for all failures and also provide a short textual > reason for the failure e.g. > > [ 1984.506184] rac1 kernel: memory offlining [mem > 0x82600000000-0x8267fffffff] failed due to signal backoff > > this tells us that the offlining has failed because of a signal pending > aka user intervention. > > ... Some of these messages will come out looking a bit odd. > @@ -1573,7 +1576,8 @@ static int __ref __offline_pages(unsigned long > start_pfn, > MIGRATE_MOVABLE, true); > if (ret) { > mem_hotplug_done(); > - return ret; > + reason = "failed to isolate range"; "memory offlining [mem ...] failed due to failed to isolate range" > + goto failed_removal > } > > arg.start_pfn = start_pfn; > @@ -1582,15 +1586,19 @@ static int __ref __offline_pages(unsigned long > start_pfn, > > ret = memory_notify(MEM_GOING_OFFLINE, &arg); > ret = notifier_to_errno(ret); > - if (ret) > - goto failed_removal; > + if (ret) { > + reason = "notifiers failure"; "memory offlining [mem ...] failed due to notifiers failure" > @@ -1607,8 +1615,10 @@ static int __ref __offline_pages(unsigned long > start_pfn, > * actually in order to make hugetlbfs's object counting consistent. > */ > ret = dissolve_free_huge_pages(start_pfn, end_pfn); > - if (ret) > - goto failed_removal; > + if (ret) { > + reason = "fails to disolve hugetlb pages"; "memory offlining [mem ...] failed due to fails to disolve hugetlb pages" Fix: --- a/mm/memory_hotplug.c~mm-memory_hotplug-print-reason-for-the-offlining-failure-fix +++ a/mm/memory_hotplug.c @@ -1576,7 +1576,7 @@ static int __ref __offline_pages(unsigne MIGRATE_MOVABLE, true); if (ret) { mem_hotplug_done(); - reason = "failed to isolate range"; + reason = "failure to isolate range"; goto failed_removal } @@ -1587,7 +1587,7 @@ static int __ref __offline_pages(unsigne ret = memory_notify(MEM_GOING_OFFLINE, &arg); ret = notifier_to_errno(ret); if (ret) { - reason = "notifiers failure"; + reason = "notifier failure"; goto failed_removal_isolated; } @@ -1616,7 +1616,7 @@ repeat: */ ret = dissolve_free_huge_pages(start_pfn, end_pfn); if (ret) { - reason = "fails to disolve hugetlb pages"; + reason = "failure to dissolve huge pages"; goto failed_removal_isolated; } /* check again */ _
