Thread: [lc-devel] pre4

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Hi,
    This is my second attempt since pre1. 
I think the setup procedures have been changed.
Can you give me the proper way of selecting the compress cache size and how to compile it?

Thanks 

On Thursday 23 May 2002 03:55, Patrick wrote:

Hi Patrick,

> This is my second attempt since pre1.
Nice. pre2 and pre3 had some unusual behaveness. I think its the right ti=
me=20
you test it again :)

> I think the setup procedures have been changed.
> Can you give me the proper way of selecting the compress cache size and=
 how
> to compile it?
Compiling doesn't really matter. You can give the size via bootparam=20
"compsize=3DN" or via /proc/sys/vm/comp_cache/size

I've noticed, with "Page compressing" the system gets slower, and stopps=20
reacting for less than a second if you do high i/o. Without it, no stopps=
=20
occur. With Lockbreak, not part of Compressed Cache, there are still some=
=20
stopps, but i think, Rodrigo has this stuff on his ToDo-List.

But, anyway, i cannot tell you the exact size of what it should be to get=
=20
maximum compression and also maximum speed. I've asked this yesterday too=
 on=20
this mailinglist. :) Let's wait for Rodrigo.

--=20
Kind regards
        Marc-Christian Petersen

http://sourceforge.net/projects/wolk

PGP/GnuPG Key: 1024D/569DE2E3DB441A16
Fingerprint: 3469 0CF8 CA7E 0042 7824  080A 569D E2E3 DB44 1A16
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On Thu, May 23, 2002 at 12:56:46PM +0200, Marc-Christian Petersen wrote:
> On Thursday 23 May 2002 03:55, Patrick wrote:
>
> > I think the setup procedures have been changed.
> > Can you give me the proper way of selecting the compress cache size and how
> > to compile it?
>
> Compiling doesn't really matter. You can give the size via bootparam
> "compsize=N" or via /proc/sys/vm/comp_cache/size

That's right. Recall that "N" is the number of memory pages to be used
by compressed cache.

> I've noticed, with "Page compressing" the system gets slower, and
> stopps reacting for less than a second if you do high i/o.

Is there any specific IO bound program you run that can make this
slowdown more noticeable? I'd like to fix this behaviour.

> With Lockbreak, not part of Compressed Cache, there are still some
> stopps, but i think, Rodrigo has this stuff on his ToDo-List.

Let me get this straight. Do you still have problems when running
compressed cache with lock-break enabled? If you do, even when the
page cache support is disabled?

> But, anyway, i cannot tell you the exact size of what it should be
> to get maximum compression and also maximum speed. I've asked this
> yesterday too on this mailinglist. :) Let's wait for Rodrigo.

I'd set to something between 15% and 25% of your total memory size
since we don't have adaptivity yet.

Regards,
-- 
Rodrigo S. de Castro <rc...@im...>

On Thursday 23 May 2002 15:01, Rodrigo Souza de Castro wrote:

Hi Rodrigo,

> > I've noticed, with "Page compressing" the system gets slower, and
> > stopps reacting for less than a second if you do high i/o.
> Is there any specific IO bound program you run that can make this
> slowdown more noticeable? I'd like to fix this behaviour.
i think the best program(s) to reproduce is "tar xzpf linux-2.4.18.tar.gz=
; rm=20
-rf linux-2.4.18; tar xzpf linux-2.4.18.tar.gz"

Its a Celeron 800MHz, UDMA66 IDE Disk, 256MB RAM, running Debian SID.

If i use the above program calls, Mouse in X Windows stopps reacting, eve=
n=20
Midnight Commander stops reacting for input, screen needs more time to op=
en=20
up a new session (Ctrl-A C) etc...

> > With Lockbreak, not part of Compressed Cache, there are still some
> > stopps, but i think, Rodrigo has this stuff on his ToDo-List.
> Let me get this straight. Do you still have problems when running
> compressed cache with lock-break enabled? If you do, even when the
> page cache support is disabled?
Yes, there are still some small stops if high i/o, even with page compres=
sion=20
disabled. Also, i've noticed some hours ago, my system freezes, this is w=
ith=20
Compressed Cache, Page Compression and Preempt/LockBreak. After that i've=
=20
compiled it again w/o Page compression, its up now for 3h 19mins, lemme s=
ee=20
if this works better. But i think, preempt/lockbreak stuff isn't a bad id=
ea=20
to integrate in the compressed cache code :)

> I'd set to something between 15% and 25% of your total memory size
> since we don't have adaptivity yet.
ok, i will set it :)

--=20
Kind regards
        Marc-Christian Petersen

http://sourceforge.net/projects/wolk

PGP/GnuPG Key: 1024D/569DE2E3DB441A16
Fingerprint: 3469 0CF8 CA7E 0042 7824  080A 569D E2E3 DB44 1A16
Key available at wwwkeys.pgp.net.   Encrypted e-mail preferred.

On Thu, May 23, 2002 at 09:55:29AM +0800, Patrick wrote:
> I think the setup procedures have been changed.
> Can you give me the proper way of selecting the compress cache size

Initial compressed cache size can only be set by kernel parameter
now. During your uptime, you can set compressed cache size by echoing
a new value to the file 

/proc/sys/vm/comp_cache/size

In both cases, the parameter is the number of memory pages (4096 bytes
on i386). I want to make it soon similar to "mem=" kernel parameter
where you can have the input as megabytes instead of memory pages.

Note: there's no way to set the compressed cache size in kernel
compilation process anymore.

> and how to compile it?

I updated yesterday some installation instruction on our main page[1],
so take a look at the "How to apply the Patches" section. If you still
have troubles, please send us an email.

[1] http://linuxcompressed.sourceforge.net/

Regards,
-- 
Rodrigo S. de Castro <rc...@im...>

On Thu, May 23, 2002 at 09:47:41AM -0300, Rodrigo Souza de Castro wrote:
> In both cases, the parameter is the number of memory pages (4096
> bytes on i386). I want to make it soon similar to "mem=" kernel
> parameter where you can have the input as megabytes instead of
> memory pages.

I already changed the code to accept the input the way mem= does and
the code is already in CVS (0.23pre5 will have it). Thus, we will be
able to enter values like compsize=16M, 1024K or even 1G (although the
compressed cache cannot be that large) without having to convert the
value into memory pages.

-- 
Rodrigo S. de Castro <rc...@im...>

Thread: [lc-devel] pre4

linuxcompressed-devel