Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 3 Oct 2001 13:30:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 3 Oct 2001 13:30:12 -0400 Received: from chiara.elte.hu ([157.181.150.200]:63240 "HELO chiara.elte.hu") by vger.kernel.org with SMTP id ; Wed, 3 Oct 2001 13:30:04 -0400 Date: Wed, 3 Oct 2001 19:28:07 +0200 (CEST) From: Ingo Molnar Reply-To: To: jamal Cc: , Alexey Kuznetsov , Robert Olsson , Benjamin LaHaise , , Linus Torvalds , Alan Cox , Simon Kirby Subject: Re: [announce] [patch] limiting IRQ load, irq-rewrite-2.4.11-B5 In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 3 Oct 2001, jamal wrote: > use the netif_rx() return code and hardware flowcontrol to fix it. i'm using hardware flowcontrol in the patch, but at a different, higher level. This part of the do_IRQ() code disables the offending IRQ source: [...] desc->status |= IRQ_MITIGATED|IRQ_PENDING; __disable_irq(desc, irq); which in turn stops that device as well sooner or later. Optionally, in the future, this can be made more finegrained for chipsets that support device-independent IRQ mitigation features, like the USB 2.0 EHCI feature mentioned by David Brownell. i'd prefer it if all subsystems and drivers in the kernel behaved properly and limited their IRQ load - but this does not always happen and users are hit by irq overload situations. Your NAPI patch, or any driver/subsystem that does flowcontrol accurately should never be affected by it in any way. No overhead, no performance hit. Ingo - 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/