On Mon, 8 Aug 2011 15:06:58 +0400 Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx> wrote: > Commit v2.6.33-5448-g6457474 (vmscan: detect mapped file pages used only once) > greatly decreases lifetime of single-used mapped file pages. > Unfortunately it also decreases life time of all shared mapped file pages. > Because after commit v2.6.28-6130-gbf3f3bc (mm: don't mark_page_accessed in fault path) > page-fault handler does not mark page active or even referenced. > > Thus page_check_references() activates file page only if it was used twice while > it stays in inactive list, meanwhile it activates anon pages after first access. > Inactive list can be small enough, this way reclaimer can accidentally > throw away any widely used page if it wasn't used twice in short period. > > After this patch page_check_references() also activate file mapped page at first > inactive list scan if this page is already used multiple times via several ptes. We have quite a few acks on these two patches, but everyone wants to see detailed performance testing. That hasn't happened, and caution dictates that I hold these patches out of linux-3.2, pending that testing. Of course, you're not the only person who can undertake that testing (hint). -- 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>