On 01/25/2012 01:58 PM, Dan Magenheimer wrote: > (Feedback welcome if there is a different/better way to do this > without using a page flag!) > > Since about 2.6.27, the page replacement algorithm maintains > an "active" bit to help decide which pages are most eligible > to reclaim, see http://linux-mm.org/PageReplacementDesign > > This "active' information is also useful to cleancache but is lost > by the time that cleancache has the opportunity to preserve the > pageful of data. This patch adds a new page flag "WasActive" to > retain the state. The flag may possibly be useful elsewhere. I guess cleancache itself is clearing the bit, right? I didn't see any clearing going on in the patch. I do think it also needs to get cleared on the way in to the page allocator. Otherwise: PageSetWasActive(page); free_page(page); ... another_user_page = get_free_page() // now cleancache sees the active bit for the prev user Or am I missing somewhere it gets cleared non-explicitly somewhere? -- 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>