On Sat, Mar 3, 2018 at 1:40 AM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Sat, 3 Mar 2018 01:12:26 +0100 Daniel Vacek <neelx@xxxxxxxxxx> wrote: > >> Commit b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns >> where possible") introduced a bug where move_freepages() triggers a >> VM_BUG_ON() on uninitialized page structure due to pageblock alignment. > > b92df1de5d28 was merged a year ago. Can you suggest why this hasn't > been reported before now? Yeah. I was surprised myself I couldn't find a fix to backport to RHEL. But actually customers started to report this as soon as 7.4 (where b92df1de5d28 was merged in RHEL) was released. I remember reports from September/October-ish times. It's not easily reproduced and happens on a handful of machines only. I guess that's why. But that does not make it less serious, I think. Though there actually is a report here: https://bugzilla.kernel.org/show_bug.cgi?id=196443 And there are reports for Fedora from July: https://bugzilla.redhat.com/show_bug.cgi?id=1473242 and CentOS: https://bugs.centos.org/view.php?id=13964 and we internally track several dozens reports for RHEL bug https://bugzilla.redhat.com/show_bug.cgi?id=1525121 Enough? ;-) > This makes me wonder whether a -stable backport is really needed... For some machines it definitely is. Won't hurt either, IMHO. --nX -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>