From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941301AbcKXUVX (ORCPT ); Thu, 24 Nov 2016 15:21:23 -0500 Received: from mail-pg0-f53.google.com ([74.125.83.53]:33332 "EHLO mail-pg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934007AbcKXUVU (ORCPT ); Thu, 24 Nov 2016 15:21:20 -0500 From: Joel Fernandes To: linux-kernel@vger.kernel.org Cc: Joel Fernandes , Steven Rostedt , Thomas Gleixner , John Stultz , Ingo Molnar Subject: [PATCH v3 0/3] timekeeping: Introduce a fast boot clock derived from fast monotonic clock Date: Thu, 24 Nov 2016 12:20:48 -0800 Message-Id: <1480018851-3796-1-git-send-email-joelaf@google.com> X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently no trace clock can account for suspend time, using monotonic during tracing in the suspend path means the trace times wont be advaced. Using the boot clock with ktime_get_with_offset is not an option due to live locking concerns in NMI context as suggested by Thomas [1]. These patches add a fast boot clock based on fast monotonic clock and adds a trace clock based on it. Instead of bloating the optimal case [2], these patches present a simple approach. Thanks Thomas for making documentation suggestions for effects of this approach [3]. [1] https://lkml.org/lkml/2016/11/20/75 [2] https://www.spinics.net/lists/kernel/msg2389485.html [3] https://lkml.org/lkml/2016/11/23/166 Joel Fernandes (3): timekeeping: Add a fast and NMI safe boot clock trace: Add an option for boot clock as trace clock trace: Update documentation for mono, mono_raw and boot clock Documentation/trace/ftrace.txt | 20 ++++++++++++++++++++ include/linux/timekeeping.h | 1 + kernel/time/timekeeping.c | 28 ++++++++++++++++++++++++++++ kernel/trace/trace.c | 1 + 4 files changed, 50 insertions(+) Cc: Steven Rostedt Cc: Thomas Gleixner Cc: John Stultz Cc: Ingo Molnar -- 2.8.0.rc3.226.g39d4020