lkml.org 
[lkml]   [2013]   [Sep]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] ethernet/arc/arc_emac: Fix huge delays in large file copies
From
From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Date: Wed, 4 Sep 2013 17:17:15 +0530

> copying large files to a NFS mounted host was taking absurdly large
> time.
>
> Turns out that TX BD reclaim had a sublte bug.
>
> Loop starts off from @txbd_dirty cursor and stops when it hits a BD
> still in use by controller. However when it stops it needs to keep the
> cursor at that very BD to resume scanning in next iteration. However it
> was erroneously incrementing the cursor, causing the next scan(s) to
> fail too, unless the BD chain was completely drained out.
>
> [ARCLinux]$ ls -l -sh /disk/log.txt
> 17976 -rw-r--r-- 1 root root 17.5M Sep /disk/log.txt
>
> ========== Before =====================
> [ARCLinux]$ time cp /disk/log.txt /mnt/.
> real 31m 7.95s
> user 0m 0.00s
> sys 0m 0.10s
>
> ========== After =====================
> [ARCLinux]$ time cp /disk/log.txt /mnt/.
> real 0m 24.33s
> user 0m 0.00s
> sys 0m 0.19s
>
> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Applied.


\
 
 \ /
  Last update: 2013-09-05 20:41    [W:0.061 / U:0.784 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site