* MinChan Kim <minchan.kim@xxxxxxxxx> [2010-12-08 11:15:19]: > On Wed, Dec 8, 2010 at 10:56 AM, KAMEZAWA Hiroyuki > <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: > > On Wed, 8 Dec 2010 10:43:08 +0900 > > Minchan Kim <minchan.kim@xxxxxxxxx> wrote: > > > >> Hi Kame, > >> > > Hi, > > > >> > I wonder ...how about adding "victim" list for "Reclaim" pages ? Then, we don't need > >> > extra LRU rotation. > >> > >> It can make the code clean. > >> As far as I think, victim list does following as. > >> > >> 1. select victim pages by strong hint > >> 2. move the page from LRU to victim > >> 3. reclaimer always peeks victim list before diving into LRU list. > >> 4-1. If the victim pages is used by others or dirty, it can be moved > >> into LRU, again or remain the page in victim list. > >> If the page is remained victim, when do we move it into LRU again if > >> the reclaimer continues to fail the page? > > When sometone touches it. > > > >> We have to put the new rule. > >> 4-2. If the victim pages isn't used by others and clean, we can > >> reclaim the page asap. > >> > >> AFAIK, strong hints are just two(invalidation, readahead max window heuristic). > >> I am not sure it's valuable to add new hierarchy(ie, LRU, victim, > >> unevictable) for cleaning the minor codes. > >> In addition, we have to put the new rule so it would make the LRU code > >> complicated. > >> I remember how unevictable feature merge is hard. > >> > > yes, it was hard. > > > >> But I am not against if we have more usecases. In this case, it's > >> valuable to implement it although it's not easy. > >> > > > > I wonder "victim list" can be used for something like Cleancache, when > > we have very-low-latency backend devices. > > And we may able to have page-cache-limit, which Balbir proposed as. > > Yes, I thought that, too. I think it would be a good feature in embedded system. > > > > > - kvictimed? will move unmappedd page caches to victim list > > This may work like a InactiveClean list which we had before and make > > sizing easy. > > > > Before further discuss, we need customer's confirm. > We know very well it is very hard to merge if anyone doesn't use. > > Balbir, What do think about it? > The idea seems interesting, I am in the process of refreshing my patches for unmapped page cache control. I presume the process of filling the victim list will be similar to what I have or unmapped page cache isolation. > > > Thanks, > > -Kame > > > > > > > > > > > > -- > Kind regards, > Minchan Kim -- Three Cheers, Balbir -- 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>