On Tue, Oct 18, 2016 at 03:12:45PM +0800, zhouxianrong@xxxxxxxxxx wrote: > From: z00281421 <z00281421@xxxxxxxxxxxxxxxxxxxx> > > bdi flusher may enter page alloc slow path due to writepage and kmalloc. > in that case the flusher as a direct reclaimer should not be throttled here > because it can not to reclaim clean file pages or anaonymous pages > for next moment; furthermore writeback rate of dirty pages would be > slow down and other direct reclaimers and kswapd would be affected. > bdi flusher should be iosceduled by get_request rather than here. > > Signed-off-by: z00281421 <z00281421@xxxxxxxxxxxxxxxxxxxx> What does this patch do that PF_LESS_THROTTLE is not doing already if there is an underlying BDI? There have been a few patches like this recently that look like they might do something useful but are subtle. They really should be accompanied by a test case and data showing they either fix a functional issue (machine livelocking due to writeback not making progress) or a performance issue. -- Mel Gorman SUSE Labs -- 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>