Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932309AbVJQQCT (ORCPT ); Mon, 17 Oct 2005 12:02:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932311AbVJQQCS (ORCPT ); Mon, 17 Oct 2005 12:02:18 -0400 Received: from gw1.cosmosbay.com ([62.23.185.226]:34962 "EHLO gw1.cosmosbay.com") by vger.kernel.org with ESMTP id S932309AbVJQQCR (ORCPT ); Mon, 17 Oct 2005 12:02:17 -0400 Message-ID: <4353CADB.8050709@cosmosbay.com> Date: Mon, 17 Oct 2005 18:01:31 +0200 From: Eric Dumazet User-Agent: Mozilla Thunderbird 1.0 (Windows/20041206) X-Accept-Language: fr, en MIME-Version: 1.0 To: Linus Torvalds CC: Dipankar Sarma , Jean Delvare , Serge Belyshev , LKML , Andrew Morton , Manfred Spraul Subject: Re: VFS: file-max limit 50044 reached References: <20051017084609.GA6257@in.ibm.com> <43536A6C.102@cosmosbay.com> <20051017103244.GB6257@in.ibm.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.6 (gw1.cosmosbay.com [172.16.8.80]); Mon, 17 Oct 2005 18:01:34 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1199 Lines: 31 Linus Torvalds a ?crit : > So I suspect that the _real_ fix is: > > - for 2.6.14: remove the batching limig (or just make it much higher for > now) I would just remove it. If the limit is wrong, we crash again. And the realtime guys already are pissed off by batch=10000 anyway. > > - post-14: work on making sure rcu callbacks are done in a more timely > manner when the rcu queue gets long. This would involve TIF_RCUPENDING > and whatever else to make sure that we have timely quiescent periods, > and we do the RCU callback tasklet more often if the queue is long. > Absolutely. Keeping a count of (percpu) queued items is basically free if kept in the cache line used by list head, so the 'queue length on this cpu' is a cheap metric. A 'realtime refinement' would be to use a different maxbatch limit depending on the caller's priority : Let a softirq thread have a lower batch count than a regular user thread. Eric - 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/