Re: excessive swap-in time

Rainer Weikusat <rweikusat@xxxxxxxxxxx> wrote:

Believe it or not, but some (actually, quite a few) people are really
old enough to personally remember the time when this was the general
and not exceptional case.

And beleive it or not i am old enough to have seen Linux systems
constantly trashing under load precisely because badly chosen pages
were evicted, while the same computer worked perfectly fine
with FreeBSD. I was under the impression that this problem was solved
with recent Linux kernels. The problem is not that the computer will
not work better if i add ten times more memory and there is no paging
activity at all, of course. But that it can work well enough, and almost
at the same speed with a moderate and constant stream of paging, if the
paging algorithm is good, which means keeping statistics on what pages
are freqently used, to avoid evicting them, and avoid using big bursts
of large paging activities (this was Linux speciality) which almost
always induce trashing - that is you have to page in pages you have
recently paged out, exactly the symptom the original poster described.



--

Michel TALON

.

Relevant Pages

  • Re: excessive swap-in time
    ... | with recent Linux kernels. ... | at the same speed with a moderate and constant stream of paging, ... and still look to the kernel like easy eviction targets. ... what set of most active processes can have their working set fully swapped ...
    (comp.os.linux.development.system)
  • Re: How to set up a Linux machine that occupies the minimum memory footprint ?
    ... > Stick some extra disks in the machine and use a striped RAID swap setup. ... That just tells him how to make paging go faster. ... > If you get the right distro, it will come with a linux kernel that already ... Most distros support them ...
    (comp.os.linux.setup)
  • Re: How to set up a Linux machine that occupies the minimum memory footprint ?
    ... > Stick some extra disks in the machine and use a striped RAID swap setup. ... That just tells him how to make paging go faster. ... > If you get the right distro, it will come with a linux kernel that already ... Most distros support them ...
    (comp.os.linux.misc)
  • Re: Can a GS run Linux?
    ... A MMU that supports paging is a minimum requirement for any ... If you wish to rewrite Linux from scratch to run Apple IIgs, ... It would be non-Linux when it does not need protected mode and memory ... Fortran compiler to write your source code. ...
    (comp.sys.apple2)