From: cinap_lenrek@felloff.net
To: 9fans@9fans.net
Subject: Re: [9fans] duppage
Date: Sun, 8 Jun 2014 19:49:00 +0200 [thread overview]
Message-ID: <7f5a01030a00fc411c0dfb2f62182b6c@felloff.net> (raw)
In-Reply-To: <CAOw7k5hX=_QzB7dTrEeOOBWXfqQc=7TxFMaa2-L5NkrSzm0FqQ@mail.gmail.com>
duppage() causes the freelist to be shuffled differently. without
stuffing cached pages at the freelist tail, the tail accumulates
a uncached "stopper" page which breaks the invariant of imagereclaim
which just scans from the tail backwards as long as the pages are
cached.
imagereclaim does not move the pages to the head after uncaching them!
so by default imagereclaim prevents the cached pages before the ones
it reclaimed from being reclaimed ever.
before image reclaim: H UUUUUUUUCCCCCCCCCC T
after image reclaim: H UUUUUUUUCCCCUUUUUU T
^- as far was imagereclaim went
nwith duppage, theres always new cached pages added at the tail.
i suspect once you run out of images, imagereclaim will run constantly and
blow away the little usefull image cache you still have causing additional
reads to page them back in.
--
cinap
next prev parent reply other threads:[~2014-06-08 17:49 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-08 14:53 erik quanstrom
2014-06-08 17:15 ` cinap_lenrek
2014-06-08 17:22 ` Charles Forsyth
2014-06-08 17:34 ` erik quanstrom
2014-06-08 17:50 ` Charles Forsyth
2014-06-08 17:53 ` erik quanstrom
2014-06-08 17:54 ` cinap_lenrek
2014-06-08 18:15 ` erik quanstrom
2014-06-08 18:37 ` Charles Forsyth
2014-06-09 8:23 ` Charles Forsyth
2014-06-09 13:21 ` erik quanstrom
2014-06-10 1:35 ` erik quanstrom
2014-06-10 3:53 ` cinap_lenrek
2014-06-10 12:58 ` erik quanstrom
2014-06-10 13:56 ` Steve Simon
2014-06-10 15:30 ` erik quanstrom
2014-06-10 14:06 ` cinap_lenrek
2014-06-11 18:04 ` erik quanstrom
2014-06-08 17:49 ` cinap_lenrek [this message]
-- strict thread matches above, loose matches on Subject: below --
2012-03-13 23:55 erik quanstrom
2012-02-25 3:29 cinap_lenrek
2012-02-25 20:09 ` Charles Forsyth
2012-02-26 4:13 ` erik quanstrom
2012-02-29 10:31 ` Richard Miller
2012-02-29 14:14 ` cinap_lenrek
2012-02-29 19:35 ` Richard Miller
2012-02-29 19:50 ` cinap_lenrek
2012-03-03 9:58 ` Richard Miller
2012-03-03 19:30 ` cinap_lenrek
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