Re: 2 times faster rawio and several fixes (2.4.3aa3)

[Andrea Arcangeli <andrea@suse.de>]

On Fri, Apr 06, 2001 at 07:36:21PM +0200, Andrea Arcangeli wrote:
> 2/4Mbytes naturally aligned area). so probably I will take the vmalloc way

As expected vmalloc additional 2 tlbs aren't visible in the numbers (that
are mostly dominated by I/O anyways), I think it's the best solution to avoid
the order 2 multipage:

alpha:/home/andrea # time ./rawio-bench 
Opening /dev/raw1
Allocating 50MB of memory
Reading from /dev/raw1
Writing data to /dev/raw1

real    0m5.241s
user    0m0.002s
sys     0m1.119s
alpha:/home/andrea # time ./rawio-bench 
Opening /dev/raw1
Allocating 50MB of memory
Reading from /dev/raw1
Writing data to /dev/raw1

real    0m5.176s
user    0m0.003s
sys     0m1.128s
alpha:/home/andrea # time ./rawio-bench 
Opening /dev/raw1
Allocating 50MB of memory
Reading from /dev/raw1
Writing data to /dev/raw1

real    0m5.196s
user    0m0.002s
sys     0m1.132s
alpha:/home/andrea # time ./rawio-bench 
Opening /dev/raw1
Allocating 50MB of memory
Reading from /dev/raw1
Writing data to /dev/raw1

real    0m5.477s
user    0m0.004s
sys     0m1.146s
alpha:/home/andrea # time ./rawio-bench 
Opening /dev/raw1
Allocating 50MB of memory
Reading from /dev/raw1
Writing data to /dev/raw1

real    0m5.217s
user    0m0.004s
sys     0m1.149s
alpha:/home/andrea # 

Tomorrow maybe I will try to speed it up furhter using the desing described in
the first email.

The s/kmem_cache_alloc/vmalloc/ change is here for now and it is rock solid
for me (regression testing is still happy):

	ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/patches/v2.4/2.4.3/rawio-2

I think it's ok for inclusion.

Andrea