On Tue, 18 Oct 2011, Andrew Morton wrote: > On Tue, 18 Oct 2011 17:02:56 -0700 (PDT) > Hugh Dickins <hughd@xxxxxxxxxx> wrote: > > > A process spent 30 minutes exiting, just munlocking the pages of a large > > anonymous area that had been alternately mprotected into page-sized vmas: > > for every single page there's an anon_vma walk through all the other > > little vmas to find the right one. > > And how long did the test case take with the patch applied? 5 seconds in the case tried; but the issue is quadratic, so you can make the improvement look arbitrarily good. Hugh -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>