From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1EC3AC433B4 for ; Fri, 14 May 2021 20:52:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFF956140A for ; Fri, 14 May 2021 20:52:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232508AbhENUxm (ORCPT ); Fri, 14 May 2021 16:53:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:32384 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232491AbhENUxe (ORCPT ); Fri, 14 May 2021 16:53:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621025541; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZdLfPCTH/k2y9ae9077TQAvYD1PaILS/qKOK1BGuXAA=; b=UiytKyzlXOts1HpkFncwzMXTfRB9O1mdj6cnP/6+uHrxVuurIXa2DlWDOpvNbxIIcPNb55 w9QyW9suYTBB8aEATe21UmxGkUc4R5VX4L/VkyNNEJ0Wg1Iar8ybntv1v1p9oqJHGnhc9e sCPzfHtn96lwFsng0YcSzPaJeR9Qu9I= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-39-_r9hK2y8ONWuyCTCiBlSSA-1; Fri, 14 May 2021 16:52:19 -0400 X-MC-Unique: _r9hK2y8ONWuyCTCiBlSSA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0901D1854E24; Fri, 14 May 2021 20:52:18 +0000 (UTC) Received: from x1.bristot.me.homenet.telecomitalia.it (ovpn-113-210.rdu2.redhat.com [10.10.113.210]) by smtp.corp.redhat.com (Postfix) with ESMTP id ECA541A868; Fri, 14 May 2021 20:52:07 +0000 (UTC) From: Daniel Bristot de Oliveira To: linux-kernel@vger.kernel.org Cc: Phil Auld , Sebastian Andrzej Siewior , Kate Carcia , Daniel Bristot de Oliveira , Jonathan Corbet , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Alexandre Chartre , Clark Willaims , John Kacur , Juri Lelli , linux-doc@vger.kernel.org Subject: [PATCH V3 7/9] tracing: Add __print_ns_to_secs() and __print_ns_without_secs() helpers Date: Fri, 14 May 2021 22:51:16 +0200 Message-Id: <2c59beee3b36b15592bfbb9f26dee7f8b55fd814.1621024265.git.bristot@redhat.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steven Rostedt To have nanosecond output displayed in a more human readable format, its nicer to convert it to a seconds format (XXX.YYYYYYYYY). The problem is that to do so, the numbers must be divided by NSEC_PER_SEC, and moded too. But as these numbers are 64 bit, this can not be done simply with '/' and '%' operators, but must use do_div() instead. Instead of performing the expensive do_div() in the hot path of the tracepoint, it is more efficient to perform it during the output phase. But passing in do_div() can confuse the parser, and do_div() doesn't work exactly like a normal C function. It modifies the number in place, and we don't want to modify the actual values in the ring buffer. Two helper functions are now created: __print_ns_to_secs() and __print_ns_without_secs() They both take a value of nanoseconds, and the former will return that number divided by NSEC_PER_SEC, and the latter will mod it with NSEC_PER_SEC giving a way to print a nice human readable format: __print_fmt("time=%llu.%09u", __print_ns_to_secs(REC->nsec_val), __print_ns_without_secs(REC->nsec_val)) Cc: Jonathan Corbet Cc: Steven Rostedt Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Alexandre Chartre Cc: Clark Willaims Cc: John Kacur Cc: Juri Lelli Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Steven Rostedt Signed-off-by: Daniel Bristot de Oliveira --- include/trace/trace_events.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h index 8268bf747d6f..248090415b97 100644 --- a/include/trace/trace_events.h +++ b/include/trace/trace_events.h @@ -358,6 +358,21 @@ TRACE_MAKE_SYSTEM_STR(); trace_print_hex_dump_seq(p, prefix_str, prefix_type, \ rowsize, groupsize, buf, len, ascii) +#undef __print_ns_to_secs +#define __print_ns_to_secs(value) \ + ({ \ + u64 ____val = (u64)value; \ + do_div(____val, NSEC_PER_SEC); \ + ____val; \ + }) + +#undef __print_ns_without_secs +#define __print_ns_without_secs(value) \ + ({ \ + u64 ____val = (u64)value; \ + (u32) do_div(____val, NSEC_PER_SEC); \ + }) + #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ static notrace enum print_line_t \ @@ -736,6 +751,16 @@ static inline void ftrace_test_probe_##call(void) \ #undef __print_array #undef __print_hex_dump +/* + * The below is not executed in the kernel. It is only what is + * displayed in the print format for userspace to parse. + */ +#undef __print_ns_to_secs +#define __print_ns_to_secs(val) val / 1000000000UL + +#undef __print_ns_without_secs +#define __print_ns_without_secs(val) val % 1000000000UL + #undef TP_printk #define TP_printk(fmt, args...) "\"" fmt "\", " __stringify(args) -- 2.26.3