lkml.org 
[lkml]   [1996]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Unnecessary seeks on mounted floppies?
Date
From


>On 15 Apr 96 at 11:48, Martin Buck wrote:
>> The DOS-fs does no read-ahead on the FAT. So whenever you read a cluster of
>> a file that's located in a yet unread sector of the FAT, the head has to
>> move to track 0 to read the next part of the FAT.
[...]
>I thought in 1.2 the FAT filesystem driver would read-ahead larger
>chunks than 1.3>=59 does. This isn't perfect, but even better. I've
>noticed slow floppy access on minix filesystems, too (a lot of
>seeking). As already stated some time ago, MS-Smartdrive now reads
>complete tracks on the floppy; why not Linux? (The floppy controller
>has a read-track command, BTW)

The floppy driver does read and buffer complete tracks. However, only
one track at a time may be buffered. Thus the data is lost (and has to
be reread later) if it isn't transferred to the buffer cache before
reading the next track. For this reason, read ahead of the FAT still
would be useful.

Alain


\
 
 \ /
  Last update: 2005-03-22 13:37    [W:0.041 / U:0.248 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site