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=-15.8 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, URIBL_BLOCKED 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 C659FC433ED for ; Thu, 8 Apr 2021 14:14:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FFC86113D for ; Thu, 8 Apr 2021 14:14:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231828AbhDHOOv (ORCPT ); Thu, 8 Apr 2021 10:14:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:23075 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231795AbhDHOOp (ORCPT ); Thu, 8 Apr 2021 10:14:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617891272; 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=DAzhYR92pz2itiH9t9ocUBT4xWWJKHfDh5zMeHkU36E=; b=K1V/uvdqNXBfuoWmegCTGOWd0bRrB9lsp4vyyPTLotHMwQjG+t3pAFSLDBlLaBhAXoYtxV JUwMZgMDbi1uYHg5kHFH2QbCmQvDYQLl4ESAEU720LpfAJ00+vze5VlMx+WYJjt0xrahwO imZ5tth96EQqBwmq29kw7OqTdb8xuSo= 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-454-kTYOLZQfOkO-kOkrT9ArQw-1; Thu, 08 Apr 2021 10:14:29 -0400 X-MC-Unique: kTYOLZQfOkO-kOkrT9ArQw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 119F583DD23; Thu, 8 Apr 2021 14:14:28 +0000 (UTC) Received: from x1.com (ovpn-112-230.rdu2.redhat.com [10.10.112.230]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6EAA019CB0; Thu, 8 Apr 2021 14:14:20 +0000 (UTC) From: Daniel Bristot de Oliveira To: Steven Rostedt , linux-kernel@vger.kernel.org Cc: bristot@redhat.com, kcarcia@redhat.com, Jonathan Corbet , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Alexandre Chartre , Clark Willaims , John Kacur , Juri Lelli , linux-doc@vger.kernel.org Subject: [RFC PATCH 4/5] tracing: Add __print_ns_to_secs() and __print_ns_without_secs() helpers Date: Thu, 8 Apr 2021 16:13:22 +0200 Message-Id: <699332475304136cfd3ca66de4b67e530707c0e0.1617889883.git.bristot@redhat.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 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..c60fd1037b91 100644 --- a/include/trace/trace_events.h +++ b/include/trace/trace_events.h @@ -33,6 +33,21 @@ static const char TRACE_SYSTEM_STRING[] = \ __stringify(TRACE_SYSTEM) +#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); \ + }) + TRACE_MAKE_SYSTEM_STR(); #undef TRACE_DEFINE_ENUM @@ -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) -- 2.30.2