Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754529AbcKUWGP (ORCPT ); Mon, 21 Nov 2016 17:06:15 -0500 Received: from mail-pg0-f54.google.com ([74.125.83.54]:32787 "EHLO mail-pg0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753763AbcKUWGN (ORCPT ); Mon, 21 Nov 2016 17:06:13 -0500 From: Joel Fernandes To: linux-kernel@vger.kernel.org Cc: Joel Fernandes , Steven Rostedt , Thomas Gleixner , John Stultz , Ingo Molnar Subject: [PATCH 0/2] Introduce a fast boot clock and add it as trace clock Date: Mon, 21 Nov 2016 14:04:55 -0800 Message-Id: <1479765897-29992-1-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: 1073 Lines: 28 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 which solves both these issues. Changes since RFC: - Moved the ktime_t offsets to the end of tk_fast - use unlikely to optimize for the monotonic case [1] https://lkml.org/lkml/2016/11/20/75 Joel Fernandes (2): timekeeping: Introduce a fast boot clock derived from fast monotonic clock trace: Add an option for boot clock as trace clock kernel/time/timekeeping.c | 36 ++++++++++++++++++++++++++++++------ kernel/trace/trace.c | 1 + 2 files changed, 31 insertions(+), 6 deletions(-) Cc: Steven Rostedt Cc: Thomas Gleixner Cc: John Stultz Cc: Ingo Molnar -- 2.8.0.rc3.226.g39d4020