lkml.org 
[lkml]   [2005]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Aligning file system data
John Richard Moser wrote:
> How likely is it that I can actually align stuff to 31.5KiB on the
> physical disk, i.e. have each block be a track?

I don't think this is very likely. Even being able to find out what the
physical disk arrangement is, or whether it is consistent in terms of
track size, etc. seems unlikely.

>
> Rather than leveraging the track cache, would it be less expensive for
> me to simply read in blocks totaling about 16 or 32KiB all at once?

For block sizes that small I think that the kernel should be smart
enough to do this itself, there is no need to concern with such low
level details in the application.

> How much more latency is involved in (B) than in (C)? Does crossing a
> track boundary incur anything expensive?

Given that both the disk and the kernel will likely read far more than
32KB ahead I can't see much difference other than the overhead inside
your application..

--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/

-
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: 2005-04-06 13:31    [W:0.051 / U:2.684 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site