Re: pageout question

2010-07-26 Thread Andriy Gapon
on 26/07/2010 20:53 RW said the following: > If after the first pass with light-paging the high watermark isn't > reached then the choices are > > 1) loop and immediately do a heavy-paging pass. > > 2) wait and let the daemon get woken-up for another light-paging pass - > only go to heavy-paging

Re: pageout question

2010-07-26 Thread Andriy Gapon
on 25/07/2010 23:43 Andriy Gapon said the following: > on 25/07/2010 23:28 RW said the following: >> I didn't say it say it was guaranteed. I just think the scenario where >> a first pass ends up between the watermarks is rare. And when it >> happens I don't see a compelling reason to do extra pagi

Re: pageout question

2010-07-26 Thread RW
On Sun, 25 Jul 2010 23:43:08 +0300 Andriy Gapon wrote: > on 25/07/2010 23:28 RW said the following: > > I didn't say it say it was guaranteed. I just think the scenario > > where a first pass ends up between the watermarks is rare. And when > > it happens I don't see a compelling reason to do ex

Re: pageout question

2010-07-25 Thread Andriy Gapon
on 25/07/2010 23:28 RW said the following: > On Sun, 25 Jul 2010 17:19:41 +0300 > Andriy Gapon wrote: > >> on 25/07/2010 16:41 RW said the following: > >>> In FreeBSD the inactive queue contains disk cache pages which >>> normally provide most of the clean pages needed. In addition pages >>> are

Re: pageout question

2010-07-25 Thread RW
On Sun, 25 Jul 2010 17:19:41 +0300 Andriy Gapon wrote: > on 25/07/2010 16:41 RW said the following: > > In FreeBSD the inactive queue contains disk cache pages which > > normally provide most of the clean pages needed. In addition pages > > are dribbled out to swap, and the resulting clean pages

Re: pageout question

2010-07-25 Thread Andriy Gapon
on 25/07/2010 16:41 RW said the following: > On Sun, 25 Jul 2010 13:07:21 +0300 > Andriy Gapon wrote: > >> on 25/07/2010 02:31 RW said the following: > >>> As I understand it the hysteresis is done inside vm_pageout_scan, >>> and the expectation is that one pass will typically satisfy this >>> b

Re: pageout question

2010-07-25 Thread RW
On Sun, 25 Jul 2010 13:07:21 +0300 Andriy Gapon wrote: > on 25/07/2010 02:31 RW said the following: > > As I understand it the hysteresis is done inside vm_pageout_scan, > > and the expectation is that one pass will typically satisfy this > > because the design aims to keep enough clean pages in

Re: pageout question

2010-07-25 Thread Andriy Gapon
on 25/07/2010 02:31 RW said the following: > On Sat, 24 Jul 2010 23:23:07 +0300 > Andriy Gapon wrote: > >> There is a good deal of comments in the vm_pageout.c code that imply >> that we use a hysteresis approach to deal with low available pages >> condition. >> >> >> In general, the hysteresis,

Re: pageout question

2010-07-24 Thread RW
On Sat, 24 Jul 2010 23:23:07 +0300 Andriy Gapon wrote: > > There is a good deal of comments in the vm_pageout.c code that imply > that we use a hysteresis approach to deal with low available pages > condition. > > > In general, the hysteresis, the comments and the code make sense. > My doubt,

pageout question

2010-07-24 Thread Andriy Gapon
There is a good deal of comments in the vm_pageout.c code that imply that we use a hysteresis approach to deal with low available pages condition. Evidence 1: /* * v_free_target and v_cache_min control pageout hysteresis. Note * that these are more a measure of the VM cache queue hysteresis