Messages in this thread |  | | Date | Tue, 11 Feb 1997 22:17:54 +0300 | From | "A.N.Kuznetsov" <> | Subject | Re: Linux VM subsystem (Was: Big mallocs, mmap sorrows and double buffering.) |
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In article <3300980A.1F62@raleigh.ibm.com> you wrote: : A.N.Kuznetsov wrote: : > Linux vm manager is the dumbest one in the world 8)8) : > I tested my program on SunOS-4, SunOS-5, FreeBSD and Digital Unix, : > Linux's VM looks really pathetic.
: What exactly is missing/misdesigned?
As I understand, Linux always makes random page swapouts, that is ideal (though I am not sure) for desktop applications. But for applications running in background and using large volumes of virtual memory this algorithm breaks. Linux practically does not coalesce swapins/swapouts.
When I "swap" by hands, I get performance close to one achieved by kernel swapping algorithm used by SounOSes and Digital (It is difficult to compare results on different hardware, so that I compare curves performance(used virtual memory)). It allows to conclude, that other unices use an adaptive swapping algorithm. It would be very interesting to understand why FreeBSD wins, but studying BSD sources is pretty boring business.
Alexey Kuznetsov.
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