lkml.org 
[lkml]   [1999]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: disk head scheduling
Arvind Sankar writes:
> This patch breaks the code. The current algorithm used is that the elevator
> stops at intermediate floors when going up, but not when going down. So it
> is ok to add a floor above the top one on the current trip, or below the
> lowest on the next.

Thanks for clearing up my confusion. Now I understand what the
original code does.

What I tried to implement was two-way elevator seeking (SCAN). In my
tiny benchmark that let many threads write on random files, SCAN
showed a throughput improvement of anywhere between 0 to 20%. But I
also noticed benefits in the original algorithm (it's fairer), so I
don't know if my change makes sense.

yaz

-
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 13:50    [W:0.212 / U:0.612 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site