Just FYI: This patch landed upstream [1]. Thanks for all involved people. - Sedat - [1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=ecccd1248d6e6986130ffcc3b0d003cb46a485c0 On Fri, Dec 28, 2012 at 3:16 AM, Zlatko Calusic <zlatko.calusic@xxxxxxxx> wrote: > From: Zlatko Calusic <zlatko.calusic@xxxxxxxx> > > The unintended consequence of commit 4ae0a48b is that > wait_iff_congested() can now be called with NULL struct zone* > producing kernel oops like this: > > BUG: unable to handle kernel NULL pointer dereference > IP: [<ffffffff811542d9>] wait_iff_congested+0x59/0x140 > > This trivial patch fixes it. > > Reported-by: Zhouping Liu <zliu@xxxxxxxxxx> > Reported-and-tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Mel Gorman <mgorman@xxxxxxx> > Cc: Hugh Dickins <hughd@xxxxxxxxxx> > Signed-off-by: Zlatko Calusic <zlatko.calusic@xxxxxxxx> > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 02bcfa3..e55ce55 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2782,7 +2782,7 @@ loop_again: > if (total_scanned && (sc.priority < DEF_PRIORITY - 2)) { > if (has_under_min_watermark_zone) > count_vm_event(KSWAPD_SKIP_CONGESTION_WAIT); > - else > + else if (unbalanced_zone) > wait_iff_congested(unbalanced_zone, BLK_RW_ASYNC, HZ/10); > } > > -- > 1.8.1.rc3 > > -- > Zlatko -- 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>