lkml.org 
[lkml]   [2002]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [BENCHMARK] max bomb segment tuning with read latency 2 patch in contest
From
Date
On Fri, 2002-12-06 at 23:55, Andrew Morton wrote:
[...]
> If the SMP machine is using scsi then that tends to make the elevator
> changes less effective. Because the disk sort-of has its own internal
> elevator which in my testing on a Fujitsu disk has the same ill-advised
> design as the kernel's elevator: it treats reads and writes in a similar
> manner.
>
> Setting the tag depth to zero helps heaps.
>
> But as you're interested in `desktop responsiveness' you should be
> mostly testing against IDE disks. Their behavour tends to be quite
> different.


One interesting thing about my current setup, with all scsi or FC disks,
is that bomb never displays > 0.
Example:

elvtune /dev/sdn yields:

/dev/sdn elevator ID 17
read_latency: 8192
write_latency: 16384
max_bomb_segments: 0

elvtune -b 6 /dev/sdn yields:

/dev/sdn elevator ID 17
read_latency: 8192
write_latency: 16384
max_bomb_segments: 0

Is it because I just do volume management at the hardware level and use
whole disks? Or is that something else?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:31    [W:0.075 / U:1.524 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site