From patchwork Mon Nov 28 22:35:24 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 84468 Delivered-To: patches@linaro.org Received: by 10.140.20.101 with SMTP id 92csp1348563qgi; Mon, 28 Nov 2016 14:35:34 -0800 (PST) X-Received: by 10.84.218.72 with SMTP id f8mr55052272plm.141.1480372534063; Mon, 28 Nov 2016 14:35:34 -0800 (PST) Return-Path: Received: from mail-pf0-x234.google.com (mail-pf0-x234.google.com. [2607:f8b0:400e:c00::234]) by mx.google.com with ESMTPS id d83si56880635pfd.152.2016.11.28.14.35.33 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 28 Nov 2016 14:35:34 -0800 (PST) Received-SPF: pass (google.com: domain of john.stultz@linaro.org designates 2607:f8b0:400e:c00::234 as permitted sender) client-ip=2607:f8b0:400e:c00::234; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org; spf=pass (google.com: domain of john.stultz@linaro.org designates 2607:f8b0:400e:c00::234 as permitted sender) smtp.mailfrom=john.stultz@linaro.org; dmarc=pass (p=NONE dis=NONE) header.from=linaro.org Received: by mail-pf0-x234.google.com with SMTP id 189so27182081pfz.3 for ; Mon, 28 Nov 2016 14:35:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=JXJCPnNsbfDXwNl8uV8rGPFHa2VOPzMWjz2D48RHNf0=; b=cvjzhHDDPfinbPpFbarrKCB8VinuaN/pXE5DXAxVrxC+CjobmUYxBU2/eVpJ6+4fUo O8sOuUggYWU+o6wJetQAfoiCWT5a9R6IPPGjPNADBf5+pbS5P/wCrnBq5+1fIimiRWhp jkTF/nKU9DdMCXiHg/uVTkEsugYoigOElFbac= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=JXJCPnNsbfDXwNl8uV8rGPFHa2VOPzMWjz2D48RHNf0=; b=dWKjV80ih5rcYXgbiITaJiF+8GFjHHOleETZJz6RyK1n2854qIduQReHpgAdorb2NA k5bHPd7drT/Vz89Hm+VFWHTP89T3OxEIcYkzYQQxz1NtbB1cU/Tl66TCivYR5s0mLadY +fCom0Xt57kJ9qfQ00jXhsxpMgSoOtf1azx8A+OiBUxHFkfYYhll0iWhTZ+IfVnfRoRA EhKAqfHOHqFRROjuUiCcraOxN8k33G6ZVqo1B34SkywxT5Q57V4dG8dGVhbEF+Tn+cSe x216tatwG7MA/0G3CMuS7+D+PW+PZBiCRKkXews5NfPpMWSl3jrxttF8qahZf//gWGN6 djLw== X-Gm-Message-State: AKaTC00+2eOXgFr58FGM+9fS5ThZYDSuqzPk9/biXTysXZklc5OVn9vUA00Vz14vj/tcxJIdTic= X-Received: by 10.99.117.71 with SMTP id f7mr44052542pgn.126.1480372533766; Mon, 28 Nov 2016 14:35:33 -0800 (PST) Return-Path: Received: from localhost.localdomain ([2601:1c2:1002:83f0:4e72:b9ff:fe99:466a]) by smtp.gmail.com with ESMTPSA id r74sm89537352pfl.79.2016.11.28.14.35.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 28 Nov 2016 14:35:33 -0800 (PST) From: John Stultz To: lkml Cc: Joel Fernandes , Steven Rostedt , Thomas Gleixner , Ingo Molnar , Richard Cochran , Prarit Bhargava , John Stultz Subject: [PATCH 7/7] trace: Update documentation for mono, mono_raw and boot clock Date: Mon, 28 Nov 2016 14:35:24 -0800 Message-Id: <1480372524-15181-8-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1480372524-15181-1-git-send-email-john.stultz@linaro.org> References: <1480372524-15181-1-git-send-email-john.stultz@linaro.org> From: Joel Fernandes Documentation was missing for mono and mono_raw, add them and also for the boot clock introduced in this series. Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Richard Cochran Cc: Prarit Bhargava Reviewed-by: Thomas Gleixner Signed-off-by: Joel Fernandes Signed-off-by: John Stultz --- Documentation/trace/ftrace.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) -- 2.7.4 Acked-by: Steven Rostedt diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 185c39f..5180b09 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -362,6 +362,26 @@ of ftrace. Here is a list of some of the key files: to correlate events across hypervisor/guest if tb_offset is known. + mono: This uses the fast monotonic clock (CLOCK_MONOTONIC) + which is monotonic and is subject to NTP rate adjustments. + + mono_raw: + This is the raw monotonic clock (CLOCK_MONOTONIC_RAW) + which is montonic but is not subject to any rate adjustments + and ticks at the same rate as the hardware clocksource. + + boot: This is the boot clock (CLOCK_BOOTTIME) and is based on the + fast monotonic clock, but also accounts for time spent in + suspend. Since the clock access is designed for use in + tracing in the suspend path, some side effects are possible + if clock is accessed after the suspend time is accounted before + the fast mono clock is updated. In this case, the clock update + appears to happen slightly sooner than it normally would have. + Also on 32-bit systems, its possible that the 64-bit boot offset + sees a partial update. These effects are rare and post + processing should be able to handle them. See comments on + ktime_get_boot_fast_ns function for more information. + To set a clock, simply echo the clock name into this file. echo global > trace_clock