From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Pedro M. Rodrigues" Subject: Re: Warning - running *really* short on DMA buffers while doing file transfers Date: Thu, 26 Sep 2002 09:04:28 +0200 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <3D92B17C.9030504@myrealbox.com> References: <20020925232736.A19209@shookay.newview.com> <20020926061419.GA12862@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: List-Id: linux-scsi@vger.kernel.org To: Jens Axboe Cc: Mathieu Chouquet-Stringer , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Jens Axboe wrote: > On Wed, Sep 25 2002, Mathieu Chouquet-Stringer wrote: > >> Hello! >> >>I've upgraded a while to 2.4.19 and my box has been happy for the last 52 >>days (it's a dual PIII). Tonight while going through my logs, I've found >>these: >> >>Sep 25 22:18:41 bigip kernel: Warning - running *really* short on DMA buffers >>Sep 25 22:18:47 bigip last message repeated 55 times >>Sep 25 22:19:41 bigip last message repeated 71 times > > > This is fixed in 2.4.20-pre > > I reported this same problem some weeks ago - http://marc.theaimsgroup.com/?l=linux-kernel&m=103069116227685&w=2 . 2.4.20pre kernels solved the error messages flooding the console, and improved things a bit, but system load still got very high and disk read and write performance was lousy. Adding more memory and using a completely different machine didn't help. What did? Changing the Adaptec scsi driver to aic7xxx_old . The performance was up 50% for writes and 90% for reads, and the system load was acceptable. And i didn't even had to change the RedHat kernel (2.4.18-10) for a custom one. The storage was two external Arena raid boxes, btw. Regards, Pedro