On Thu, Jun 23, 2011 at 08:10:47AM -0400, Theodore Tso wrote: > > On Jun 23, 2011, at 2:36 AM, Andrea Righi wrote: > > > > > With the following solution when posix_fadvise(POSIX_FADV_DONTNEED) is > > called for an active page instead of removing it from the page cache it > > is added to the tail of the inactive list. Otherwise, if it's already in > > the inactive list the page is removed from the page cache. > > > Have you thought about this heuristic? If the page is active, try to > remove it from the current process's page table. If that drops the > use count of the page to zero, then drop it from the page cache; > otherwise, leave it alone. > > That way, if the page is being used by anyone else, we don't touch > the page at all. fadvise() should only affect the current process; if > it's available to non-root users, it shouldn't be affecting other > processes, and if it is being actively used by some other process, > removing it from their page tables so it can be put on the inactive > list counts as interference, doesn't it? If the page is mapped in other process page tables we don't touch the page at all (see lru_deactivate_fn in mm/swap.c). So the heuristic above it's already implemented. I should have said this explicitly in my description... -Andrea -- 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>