On Wed, Jul 7, 2010 at 5:27 AM, Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > On Tue, Jul 06, 2010 at 04:25:39PM +0100, Mel Gorman wrote: >> On Tue, Jul 06, 2010 at 08:24:57PM +0900, Minchan Kim wrote: >> > but it is still problem in case of swap file. >> > That's because swapout on swapfile cause file system writepage which >> > makes kernel stack overflow. >> >> I don't *think* this is a problem unless I missed where writing out to >> swap enters teh filesystem code. I'll double check. > > It bypasses the fs. On swapon, the blocks are resolved > (mm/swapfile.c::setup_swap_extents) and then the writeout path uses > bios directly (mm/page_io.c::swap_writepage). > > (GFP_NOFS still includes __GFP_IO, so allows swapping) > > Hannes Thanks, Hannes. You're right. Extents would be resolved by setup_swap_extents. Sorry for confusing, Mel. It was just my guessing about Kosaki's mention but he might say another story. Ignore me. -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href