Re: [lc-devel] 0.24pre8 test results and future requirements

[Bob A. <cu...@pb...>]

ok, it works fine since i compiled and installed it on my firewall.
it is nfsroot machine. i prepared version without sanity checks for next reboot there. 
comp ratio is ~ 60% there , machine is lot more responsive.

on laptop it isn't working so fine :/

it is machine with mere hdd, and squashfs patch , because part of fs is compressed - with plan to be moved to r-o flash medium when i will be able to buy such device  (they still lack of ~ 512M of DDRAM for r/w things , i wait for flash+dram 'compact flash' cards)

machine boots ok, but first sign that something is wrong is that /var/pcmcia.log can't be changed, - i/o error is reported.
then i start X and ... machine stops reading from disk just after detection of vidcards.
even after ctrl-c , no other program can read from the disk.

if i disable 'page cache compression' machine works fine :)

i get 36% compression ratio then , and lot of speedup.

i have two X servers running, and two vncviewers on each of them - one is mine, other is my gf's Xvnc. when i switch from one X to other (by changing VT) it almost doesn't swap out, and it is quite quick.
before patch it took 5-6 seconds (vs 1 sec with patch) and i had 'swap storm' during switching.




On Tue, 21 Oct 2003 02:42:53 +0200
Bob Arctor <cu...@pb...> wrote:

> 
> John R Moser sent me fixed WKdm.c , it should compile on older gcc and is C compliant :)
> 
> 
> 
> On Fri, 17 Oct 2003 19:39:34 -0400 (EDT)
> John R Moser <jm...@st...> wrote:
> 
> > bob, I've tried oM, it's neat but not something i'm interested in ATM 
> > since it was a little unstable to me.  I'd wait until 2.6 or 2.8 and just 
> > merge them there.  I'm actually hoping linus will merge grsecurity and 
> > ccache into 2.6 by the end of its testing phase, but we'd need ccache on 
> > rmap and a 2.6 grsec first.  oM is something i'm not too worried about 
> > right now.
> > 
> > One thing I'm worried about though is that the ccache patched kernel 
> > doesn't seem to like my Nvidia card.  Since Nvidia cards are common, this 
> > needs to be fixed.  I'm not sure if it's a ccache bug or an nvdriver bug, 
> > or just a kernel bug that ccache brings out.  I think ccache will work 
> > better in 2.4.22 and .23 for these though (it worked in .21 with my 
> > nvdriver) so it may just be kernel.
> > 
> > There's also the 2.4 ccache (and oM, and many other patches) issue that 
> > `iptables -t nat -I POSTROUTING -o eth0 -j MASQUERADE` doesn't seem to 
> > work due to 'target problem'.  Yes, the masq module is compiled.  Try 
> > it.  Try to fix this, since it's kind of important, NAT being popular and 
> > all.
> > 
> > Anyway, here's my test results for a kernel compile.  I think the 
> > measurement for using ccache was a bit high time-wise because I DID swap 
> > some, and so I am going to redo the test later with no swap enabled.  
> > Eventually I need to do some 20 tests under each condition.  I'm still 
> > shakey about lzo so I didn't compile its init instruction into my kernel; 
> > however, i've discovered that compalg=WK4x4 and compalg=WKdm work 
> > properly!  o.o!
> > 
> > The trivial bug on line 309 I think of proc.c that spews so much about 
> > algorithm like 13000 or something is from being called by swapout.c and 
> > trying to update the stats for the algorithm that an UNCOMPRESSED page is 
> > using when it swaps out.  Oops.  Need to make a NO_ALGORITHM_IDX entry 
> > load at boot and use that as a dump for uncompressed stats.  Also need to 
> > rewrite the page allocation code and so on.
> > 
> > I'm not going to be writing anymore code in this for now.  Go ahead and 
> > write some without me.  I don't know how to work with modules, so none of 
> > that from me.
> > 
> > Move the LZO, WKdm, and WK4x4 algs into modules and allow them to 
> > optionally be compiled in (but not default alg if loaded as modules).  
> > Give them the interface of the core central compression library (same as 
> > zlib).
> > 
> > If there is no standard interface for the compression library functions,
> > write one on top of the kernel's zlib and also place it on top of WKdm,
> > WK4x4, and LZO when you dump them into the library core.  Also, try to 
> > insert a registration system init function on top of the kernel's zlib 
> > interface, and call its init before initing compressed page cache if it 
> > is compiled in to the kernel for both compression and decompression.
> > 
> > Someone needs to check WKdm and WK4x4 to see if they are really workable 
> > for >4k pages.
> > 
> >  --Bluefox Icy
>