Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161222AbWJPIsV (ORCPT ); Mon, 16 Oct 2006 04:48:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161224AbWJPIsV (ORCPT ); Mon, 16 Oct 2006 04:48:21 -0400 Received: from mout2.freenet.de ([194.97.50.155]:40593 "EHLO mout2.freenet.de") by vger.kernel.org with ESMTP id S1161222AbWJPIsU convert rfc822-to-8bit (ORCPT ); Mon, 16 Oct 2006 04:48:20 -0400 To: "Jens Axboe" , "Peter Osterlund" From: balagi@justmail.de Subject: Re: Re: [PATCH 2/2] 2.6.19-rc1-mm1 pktcdvd: bio write congestion Cc: linux-kernel@vger.kernel.org X-Priority: 3 X-Abuse: 300631278 / unknown, unknown User-Agent: freenetMail MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Message-Id: Date: Mon, 16 Oct 2006 10:48:16 +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1814 Lines: 63 Hello, the congestion control will work with both code changes, but i am not sure, if using clear_queue_congested() and blk_congestion_wait() is the right thing to use here: it works on global level. Any other thread/driver/etc. can do a clear_queue_congested() and wake up anyone waiting on this global write or read wait queue, resulting to unneeded task switches. The driver local solution (own waitqueue) would prevent this..... -Thomas Maier ----- original Nachricht -------- Betreff: Re: [PATCH 2/2] 2.6.19-rc1-mm1 pktcdvd: bio write congestion Gesendet: So 15 Okt 2006 20:16:31 CEST Von: "Jens Axboe" > On Sat, Oct 14 2006, Peter Osterlund wrote: > > "Thomas Maier" writes: > > > > > Hello, > > > > > > this adds a bio write queue congestion control > > > to the pktcdvd driver with fixed on/off marks. > > > It prevents that the driver consumes a unlimited > > > amount of write requests. > > > > Thanks, this looks good in principle, but I think it can be > > implemented in a simpler way. > > > > Jens, can I please ask your opinion. Would it make sense to export the > > clear_queue_congested() and set_queue_congested() functions in > > ll_rw_blk.c so that the pktcdvd driver can use them? Something like > > this patch from a few years ago: > > > > > http://marc.theaimsgroup.com/?l=linux-kernel&m=109378210610508&w=2 > > It definitely would. Did you test, and did it work well for you? I think > it's the right approach. > > -- > Jens Axboe > > --- original Nachricht Ende ---- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/