On Mon, Jan 17, 2011 at 03:26:15PM +0100, Andrea Arcangeli wrote: > On Mon, Jan 17, 2011 at 09:10:15AM -0500, Chris Mason wrote: > > Excerpts from Andrea Arcangeli's message of 2011-01-17 00:11:35 -0500: > > > > [ crashes under load ] > > > > > > > > NOTE: with the last changes compaction is used for all order > 0 and > > > even from kswapd, so you will now be able to trigger bugs in > > > compaction or migration even with THP off. However I'm surprised that > > > you have issues with compaction... > > > > I know I mentioned this in another email, but it is kind of buried in > > other context. I reproduced my crash with CONFIG_COMPACTION and > > CONFIG_MIGRATION off. > > Ok, then it was an accident the page->lru got corrupted during > migration and it has nothing to do with migration/compaction/thp. This > makes sense because we should have noticed long ago if something > wasn't stable there. > > I reworked the fix for the two memleaks I found while reviewing > migration code for this bug (unrelated) introduced by the commit > cf608ac19c95804dc2df43b1f4f9e068aa9034ab. It was enough to move the > goto to fix this without having to add a new function (it's > functionally identical to the one I sent before). It also wouldn't > leak memory if it was compaction invoking migrate_pages (only other > callers checking the retval of migrate_pages instead of list_empty, > could leak memory). As said before, this couldn't explain your > problem, and this is only a code review fix, I never triggered this. > > This is still only for review for Minchan, not meant for inclusion > yet. > > === > Subject: when migrate_pages returns 0, all pages must have been released > > From: Andrea Arcangeli <aarcange@xxxxxxxxxx> > > In some cases migrate_pages could return zero while still leaving a > few pages in the pagelist (and some caller wouldn't notice it has to > call putback_lru_pages after commit > cf608ac19c95804dc2df43b1f4f9e068aa9034ab). > > Add one missing putback_lru_pages not added by commit > cf608ac19c95804dc2df43b1f4f9e068aa9034ab. It would be better to have another patch. > > Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx> Thanks, Andrea. -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>