Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271055AbUJUWvQ (ORCPT ); Thu, 21 Oct 2004 18:51:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271037AbUJUWsR (ORCPT ); Thu, 21 Oct 2004 18:48:17 -0400 Received: from zcars04e.nortelnetworks.com ([47.129.242.56]:3249 "EHLO zcars04e.nortelnetworks.com") by vger.kernel.org with ESMTP id S271020AbUJUWhJ (ORCPT ); Thu, 21 Oct 2004 18:37:09 -0400 Message-ID: <417839F6.7090308@nortelnetworks.com> Date: Thu, 21 Oct 2004 16:36:38 -0600 X-Sybari-Space: 00000000 00000000 00000000 00000000 From: Chris Friesen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040113 X-Accept-Language: en-us, en MIME-Version: 1.0 To: "Perez-Gonzalez, Inaky" CC: george@mvista.com, root@chaos.analogic.com, "Brown, Len" , Tim Schmielau , john stultz , lkml Subject: Re: gradual timeofday overhaul References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 977 Lines: 21 Perez-Gonzalez, Inaky wrote: > Now, the ugly case would be if number_of_context_swiches_per_second > HZ. > In HZ = 100, this could be happening, but in HZ=1000, in a single CPU > ...well, that would be TOO weird [of course, a real-time app with a > 1ms period would do that, but it'd require at least an HZ of 10000 to > work more or less ok and we'd be below the watermark]. It's easy to have >>1000 context switches per second on a server. Consider a web server that receives a network packet, issues a request to a database, hands some work off to a thread so the main app doesn't block, then sends a response. That could be a half dozen context switches per packet. If you have 20000 packets/sec coming in.... Chris - 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/