Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756589Ab1CAP70 (ORCPT ); Tue, 1 Mar 2011 10:59:26 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:44970 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753070Ab1CAP7Z (ORCPT ); Tue, 1 Mar 2011 10:59:25 -0500 Subject: Re: [PATCH 3/6] perf record: add time-of-day option From: Peter Zijlstra To: David Ahern Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, acme@ghostprotocols.net, mingo@elte.hu, fweisbec@gmail.com, paulus@samba.org, tglx@linutronix.de In-Reply-To: <4D6D13C6.5020807@cisco.com> References: <1298865151-23656-1-git-send-email-daahern@cisco.com> <1298865151-23656-4-git-send-email-daahern@cisco.com> <1298989751.5226.863.camel@laptop> <4D6D0438.2090901@cisco.com> <1298993714.5226.871.camel@laptop> <4D6D13C6.5020807@cisco.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 01 Mar 2011 17:00:50 +0100 Message-ID: <1298995250.5226.882.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 642 Lines: 16 On Tue, 2011-03-01 at 08:41 -0700, David Ahern wrote: > realtime-clock counter is created with a period N. How do you correlate > perf_clock to time-of-day until now + N? You scan fwd? Since its at most N time ahead you're scanning fwd its still constant time. Thing is, I'm really not convinced this is a very useful ioctl() in generic, and ioctl()s really need a good justification to add. -- 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/