Re: X much slower in 2.0.24 than in 1.2.13

Keith Rohrer (kwrohrer@uiuc.edu)
Tue, 05 Nov 1996 04:18:36 -0600


Alan Cox wrote:
>
> > | Interesting. These only change the size of some fields. It may be a field
> > | size issue. Note that you dont want to run with that sock.h patch reversed
> > | as it lets people crash your machine..
> >
> > The 2.0.24 changes to "struct sock" in "linux/include/net/sock.h" push
> > its size, in my kernel, up to 0x1fc. This new size, plus the
> > "kmalloc"'s "block_header" is just big enough to push "struct sock"
> > allocations to the next allocation order.
> We hardly ever allocate a struct sock
Since the last patch I see to sock.h just adds one field, but adds it in
the middle rather than at the tail, that might be shoving something (or
many somethings) off the end of a cache line... Has anyone tried
optimizing the ordering for cache friendliness, or is it the way it is
for some other reason?

Keith

-- 
Their priests and their friars/Behold me in dread
Because I still love you,/My love, and you're dead.
	---Dead Can Dance, "I Am Stretched On Your Grave"