Hello, On Mon, Nov 27, 2017 at 09:37:30AM +0800, Jiang Biao wrote: > When running ltp stress test for 7*24 hours, the kernel occasionally > complains the following warning continuously, > > mb_cache_shrink_scan+0x0/0x3f0 negative objects to delete > nr=-9222526086287711848 > mb_cache_shrink_scan+0x0/0x3f0 negative objects to delete > nr=-9222420761333860545 > mb_cache_shrink_scan+0x0/0x3f0 negative objects to delete > nr=-9222287677544280360 > ... > > The tracing result shows the freeable(mb_cache_shrink_scan returns) > is -1, which causes the continuous accumulation and overflow of > total_scan.
Good catch. > > This patch make do_shrink_slab more robust when > shrinker->count_objects return negative freeable. Shrinker.h says count_objects should return 0 if there are no freeable objects, not -1. So if something returns -1, changing it with returning 0 would be more proper fix. Thanks. > > Signed-off-by: Jiang Biao <jiang.bi...@zte.com.cn> > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index eb2f031..3ea28f0 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -323,7 +323,7 @@ static unsigned long do_shrink_slab(struct shrink_control > *shrinkctl, > long scanned = 0, next_deferred; > > freeable = shrinker->count_objects(shrinker, shrinkctl); > - if (freeable == 0) > + if (freeable <= 0) > return 0; > > /* > -- > 2.7.4 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majord...@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"d...@kvack.org";> em...@kvack.org </a>
