From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 2/7] sata_mv: deal with interrupt coalescing interrupts Date: Sat, 20 May 2006 09:24:19 -0400 Message-ID: <446F1883.9090601@pobox.com> References: <11480537082648-git-send-email-htejun@gmail.com> <446DEE92.50102@pobox.com> <200605191614.00023.liml@rtr.ca> <200605191624.56928.liml@rtr.ca> <446E9BE1.3060700@pobox.com> <446F160C.40204@rtr.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:32965 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S964844AbWETNYW (ORCPT ); Sat, 20 May 2006 09:24:22 -0400 In-Reply-To: <446F160C.40204@rtr.ca> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Mark Lord Cc: linux-ide@vger.kernel.org Mark Lord wrote: > Jeff Garzik wrote: >> Applied, though I would like a follow-up which simply guarantees that >> irq coalescing is off. > > Perhaps. I'm getting pressure to do the exact opposite from users > of this chipset --> they'd like IRQ coalescing to be guaranteed to > be turned *on*. Maybe a sysfs attr for it, with default == off ? Yes, I should have been more clear. Support is fine, as long as the default is off. Unless you have a _lot_ of ports active at the same time, irq coalescing can increase latency. Ideally, for this, AHCI, and any other SATA controller that does coalescing, we have a runtime dynamic trigger that turns on coalescing when interrupt traffic exceeds a runtime limit. Jeff