From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vineet Gupta Subject: Re: [PATCH] ethernet/arc/arc_emac: Fix huge delays in large file copies Date: Mon, 16 Sep 2013 11:13:48 +0530 Message-ID: <52369A94.5060900@synopsys.com> References: <1378295235-18928-1-git-send-email-vgupta@synopsys.com> <20130905.142530.732425484460470485.davem@davemloft.net> <522EBBD2.1060003@synopsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: David Miller , , , , "stable@vger.kernel.org" To: greg Kroah-Hartman Return-path: In-Reply-To: <522EBBD2.1060003@synopsys.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 09/10/2013 11:57 AM, Vineet Gupta wrote: > On 09/05/2013 11:55 PM, David Miller wrote: >> From: Vineet Gupta >> 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 >> >> Applied. >> > > Hi Greg, > > This needs a stable backport (3.11). > Mainline commit 27082ee1b92f4d41e78b85 > > Thx, > -Vineet Hi Greg, I didn't spot this one in your stable-queue for 3.11. Please apply. Thx, Vineet