Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751304AbZKDFrX (ORCPT ); Wed, 4 Nov 2009 00:47:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751196AbZKDFrW (ORCPT ); Wed, 4 Nov 2009 00:47:22 -0500 Received: from mail.infogain.com ([65.223.106.147]:24145 "EHLO mail.infogain.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751054AbZKDFrW convert rfc822-to-8bit (ORCPT ); Wed, 4 Nov 2009 00:47:22 -0500 X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: why kernel implement "udelay" by cpu instructions? Date: Wed, 4 Nov 2009 11:15:01 +0530 Message-ID: In-Reply-To: <3e8340490911032136x56696cc3u3b6f3b1e5d132324@mail.gmail.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: why kernel implement "udelay" by cpu instructions? Thread-Index: AcpdEKHBSZ0pOG6GT3eMJZjqYq/rcQAAR9Tg References: <3a665c760911011913q268b010cqb5da4f79df995b9b@mail.gmail.com> <4AEE63E2.9010003@redhat.com> <3a665c760911031819t2fef1720q3e2f542a2e56a3d0@mail.gmail.com> <3e8340490911032136x56696cc3u3b6f3b1e5d132324@mail.gmail.com> From: "Rajat Jain" To: "Bryan Donlan" Cc: "loody" , "Rik van Riel" , , "Kernel Newbies" X-OriginalArrivalTime: 04 Nov 2009 05:45:44.0976 (UTC) FILETIME=[0D70A100:01CA5D12] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 660 Lines: 20 Hi, > > I thought hrtimers allow higher-precision wakeups these days? > Of course, if you only want to sleep for a few microseconds, the > context switch might take longer than you want to sleep... Yes, that is right. Sorry, I missed that. But that is purely HW dependent - if your HW providea a high precision timer (Such as HPET on latest Intel machines), that can be used for quicker sleeps. Thanks, Rajat -- 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/