Subject: kern/35741: PDPOLICY_CLOCKPRO has no tuning parameters analogous to vm.filemax, etc.
To: None <firstname.lastname@example.org, email@example.com,>
From: None <firstname.lastname@example.org>
Date: 02/20/2007 18:20:00
>Synopsis: PDPOLICY_CLOCKPRO has no tuning parameters analogous to vm.filemax, etc.
>Arrival-Date: Tue Feb 20 18:20:00 +0000 2007
>Originator: Blair Sadewitz
NetBSD dexamyl 4.99.12 NetBSD 4.99.12 (DEXAMYL) #3: Mon Feb 19 18:37:01 EST 2007 blair@dexamyl:/home/blair/build/obj/sys/arch/amd64/compile/DEXAMYL amd64
PDPOLICY_CLOCKPRO is clearly a superior page replacement policy. However, for workloads that involve, for instance, a lot of anonymous/exec memory and don't need a lot of file cache, the system starts swapping out pages to disk like mad. Presumably, with heavy disk I/O, file pages become 'hotter' than anon/exec pages for running applications. This can cause a "desktop" environment such as KDE or GNOME to slow to a virtual standstill in the face of relentless swapping.
Build a kernel with PDPOLICY_CLOCKPRO, start a lot of bloated applications, then do a lot of disk I/O. I have had two others confirm this problem.
Not sure at all. Add "weighting" to items in listq?