Re: Kernel 2.4.16 & Heavy I/O

Pablo Borges (pablo.borges@uol.com.br)
Thu, 6 Dec 2001 16:28:51 -0200


So ppl, plz help-me find this problem.

Once upon a time, I had 30/60 days uptime on my workstation, only rebooting for kernel updates or power faults. Nowadays, I've to reboot my machine every day because there's no physical memory available. I watch my disk burning in heavy I/O to open my X, browser, etc and stuff.

Then, one day, I decided to init 1; umount all and I saw the amazing release of 70% for my physical memory. I assumed that the disk cache had it all.

So, if this is correct, I want or to keep the cache under control or to flush it when I want. François Cami told me there is an option on aa's VM that helps me with that

> easy.
> echo 400 > /proc/sys/vm/vm_mapped_ratio
> the higher the number, the smaller/less aggressive the disk cache.

Tnx for your help,
[]'s
Pablo

On Thu, 6 Dec 2001 19:10:56 +0100 (CET)
Roy Sigurd Karlsbakk <roy@karlsbakk.net> wrote:

> Is it really neccecary? Free memory's a waste! The cache will be
> discarded the moment an application needs the memory.
>
> what's the problem? It speeds up disk I/O for recently used files
>
> On Thu, 6 Dec 2001, Pablo Borges wrote:
>
> >
> > Don't we have a "dont't eat my whole memory, disk cache" option on
> > linux ?
> >
> >
> > On Wed, 5 Dec 2001 21:07:42 +0100 (CET)
> > Roy Sigurd Karlsbakk <roy@karlsbakk.net> wrote:
> >
> > > > > Absolutely all free memory may be used for disk caching. So
> > > > > no, you can't get a bigger cache because it is already at
> > > > > the highest possible setting. You don't have more memory
> > > > > for this - all is used already.
> > > >
> > > > May I limit this memory ? For a long time I'm working all day with
> > > > no physical memory available.
> > >
> > > You can try rtlinux. In rtlinux (realtime linux), you tell linux how
> > > much memory the kernel will have access to, and let specially
> > > written apps to take the rest
> > > --
> > > Roy Sigurd Karlsbakk, MCSE, MCNE, CLS, LCA
> > >
> > > Computers are like air conditioners.
> > > They stop working when you open Windows.
> > >
> > > -
> > > To unsubscribe from this list: send the line "unsubscribe
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> > > Please read the FAQ at http://www.tux.org/lkml/
> > >
> >
> >
> > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> > Pablo Borges pablo.borges@uol.com.br
> > -------------------------------------------------------------------
> > ____ Tecnologia UOL
> > / \ Debian:
> > | =_/ The 100% suck free linux distro.
> > \
> > \ SETI is lame. http://www.distributed.net
> > Dnetc is XNUG!
> >
>
> --
> Roy Sigurd Karlsbakk, MCSE, MCNE, CLS, LCA
>
> Computers are like air conditioners.
> They stop working when you open Windows.
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel"
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>

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Pablo Borges pablo.borges@uol.com.br
-------------------------------------------------------------------
____ Tecnologia UOL
/ \ Debian:
| =_/ The 100% suck free linux distro.
\
\ SETI is lame. http://www.distributed.net
Dnetc is XNUG!

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