* KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> [2010-06-11 10:54:41]: > On Thu, 10 Jun 2010 17:07:32 -0700 > Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> wrote: > > > On Thu, 2010-06-10 at 19:55 +0530, Balbir Singh wrote: > > > > I'm not sure victimizing unmapped cache pages is a good idea. > > > > Shouldn't page selection use the LRU for recency information instead > > > > of the cost of guest reclaim? Dropping a frequently used unmapped > > > > cache page can be more expensive than dropping an unused text page > > > > that was loaded as part of some executable's initialization and > > > > forgotten. > > > > > > We victimize the unmapped cache only if it is unused (in LRU order). > > > We don't force the issue too much. We also have free slab cache to go > > > after. > > > > Just to be clear, let's say we have a mapped page (say of /sbin/init) > > that's been unreferenced since _just_ after the system booted. We also > > have an unmapped page cache page of a file often used at runtime, say > > one from /etc/resolv.conf or /etc/passwd. > > > > Hmm. I'm not fan of estimating working set size by calculation > based on some numbers without considering history or feedback. > > Can't we use some kind of feedback algorithm as hi-low-watermark, random walk > or GA (or somehing more smart) to detect the size ? > Could you please clarify at what level you are suggesting size detection? I assume it is outside the OS, right? -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>