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 Content-Length: 1305 Lines: 31 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