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

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

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