lkml.org 
[lkml]   [2006]   [Mar]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Readahead value 128K? (was Re: Drastic Slowdown of 'fseek()' Calls From 2.4 to 2.6 -- VMM Change?)
Marr wrote:
>
> I tried turning 'readahead' off entirely ('hdparm -A0 /dev/hda') and, although

No, that should be "hdparm -a0 /dev/hda" (lowercase "-a").
And the same "-a" for all of your other test variants.

If you did it all with "-A", then the results are invalid,
and need to be redone.

The hdparm manpage explains this, but in a nutshell, "-A" is the
low-level drive firmware "look-ahead" mechanism, whereas "-a" is
the Linux kernel "read-ahead" scheme.

In general, most uppercase hdparm flags are drive *firmware* settings.

Cheers
-
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: 2006-03-12 23:18    [W:0.085 / U:0.172 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site