From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: References: <4A0E7310-9D9D-45C5-88A3-62B4A3191267@quintile.net> <20121103163103.GA48522@intma.in> <5cff355142bfe83410dce1c3fc321f25@kw.quanstro.net> <20121103165100.GA63071@intma.in> <7cd2c11374f75d628a5bb5e1f1d0919e@kw.quanstro.net> <20121103171322.GA76929@intma.in> <20121103174555.GA96072@intma.in> Date: Sat, 3 Nov 2012 18:48:47 +0000 Message-ID: From: Charles Forsyth To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: multipart/alternative; boundary=047d7b33dc5cdaec0404cd9bb394 Subject: Re: [9fans] Kernel panic when allocating a huge memory Topicbox-Message-UUID: d2f3749e-ead7-11e9-9d60-3106f5b1d025 --047d7b33dc5cdaec0404cd9bb394 Content-Type: text/plain; charset=UTF-8 local paging algorithms can avoid thrashing: "the process pages against itself". global paging algorithms typically do not (invariably do not, in my experience, but most people use essentially the same one, so there might be some that worked). Wilkes has a nice discussion of paging algorithms as an application of control theory in "The Dynamics of Paging". http://comjnl.oxfordjournals.org/content/16/1/4.short "It is notorious that the use of apparently innocuous scheduling and paging algorithms can give rise to the type of unstable behaviour known as thrashing." On 3 November 2012 17:57, erik quanstrom wrote: > other factors, like global knowledge of memory use stats and page > duplication > should put the vm in an even better position than general queueing theory > would suggest to make decisions on what pages to move to disk wrt. global > (that is total machine) throughput. > --047d7b33dc5cdaec0404cd9bb394 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
local paging algorithms can avoid thrashing: &qu= ot;the process pages against itself".
= global paging algorithms typically do not (invariably do not, in my experie= nce, but most people use essentially the same one, so there might be some t= hat worked).

Wilkes has = a nice discussion of paging algorithms as an application of control theory<= /div>
in "The Dynamics of Paging".=C2= =A0http:/= /comjnl.oxfordjournals.org/content/16/1/4.short

"It is= notorious that the use of apparently innocuous scheduling and paging algor= ithms can give rise to the type of unstable behaviour known as thrashing.&q= uot;


On 3 November 201= 2 17:57, erik quanstrom <quanstro@quanstro.net> wrote:
other factors, like global knowledge of memory use stats and page dupl= ication
should put the vm in an even better position than general queueing theory would suggest to make decisions on what pages to move to disk wrt. global (that is total machine) throughput.

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