On Thu, 22 Jul 2010 10:19:30 +0100 Mel Gorman <mel@xxxxxxxxx> wrote: > On Thu, Jul 22, 2010 at 08:57:34AM +0900, KAMEZAWA Hiroyuki wrote: > > On Wed, 21 Jul 2010 15:27:10 +0100 > > Mel Gorman <mel@xxxxxxxxx> wrote: > > 1 tick penalty seems too large. I hope we can have some waitqueue in future. > > > > congestion_wait() if congestion occurs goes onto a waitqueue that is > woken if congestion clears. I didn't measure it this time around but I > doubt it waits for HZ/10 much of the time. > Okay. > > > > > - nr_reclaimed += shrink_page_list(&page_list, sc, PAGEOUT_IO_SYNC); > > > > > + /* > > > > > + * The attempt at page out may have made some > > > > > + * of the pages active, mark them inactive again. > > > > > + */ > > > > > + nr_active = clear_active_flags(&page_list, NULL); > > > > > + count_vm_events(PGDEACTIVATE, nr_active); > > > > > + > > > > > + nr_reclaimed += shrink_page_list(&page_list, sc, > > > > > + PAGEOUT_IO_SYNC, &nr_dirty); > > > > > + } > > > > > > > > Just a question. This PAGEOUT_IO_SYNC has some meanings ? > > > > > > > > > > Yes, in pageout it will wait on pages currently being written back to be > > > cleaned before trying to reclaim them. > > > > > Hmm. IIUC, this routine is called only when !current_is_kswapd() and > > pageout is done only whne current_is_kswapd(). So, this seems .... > > Wrong ? > > > > Both direct reclaim and kswapd can reach shrink_inactive_list > > Direct reclaim > do_try_to_free_pages > -> shrink_zones > -> shrink_zone > -> shrink_list > -> shrink_inactive list <--- the routine in question > > Kswapd > balance_pgdat > -> shrink_zone > -> shrink_list > -> shrink_inactive_list > > pageout() is still called by direct reclaim if the page is anon so it > will synchronously wait on those if PAGEOUT_IO_SYNC is set. Ah, ok. I missed that. Thank you for kindly clarification. Thanks, -Kame -- 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=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>