lkml.org 
[lkml]   [1999]   [Nov]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [Patch] shm bug introduced with pagecache in 2.3.11
Date
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
> > You've lost:
>
> > Computer: K6-200, 128 MB Ram, Symbios 810 scsi controller, Fujitsu
> > Magneto-Optical drive, 620 MB [I have no empty scsi disc left :(],
>
> So you benchmarked with a very slow I/O device. Ok that should mean its
> silly numbers for both tied entirely to the seek rate of the media
>
Yes, intentionally, that was the slowest disk I found:
Linux single-threads the pageing-io, ie it cannot reorder the read
operations.
I wrote that this is a huge disadvantage, and the numbers show that.

> > 620,000,000 bytes test file, fat filesystem, the same disk is used for
> > NT and Linux.
>
> Linux FAT performance is slow. Try NTFS (or FAT) versus ext2. That would
> be interesting.
I'll try it with a faster disk, but initial tests show that :
- NT gets faster if I add further threads
- Linux cannot reorder the disk io, and it remains at the same performance
for 1 thread and for 64 threads.
- the benchmark is io bound, ie the internal efficiency of the os doesn't
matter.

Jeff Garzik wrote:
> Is this test done on kernel 2.3.28?
2.3.27
--
Manfred




-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:55    [W:1.331 / U:0.372 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site