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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 CC5E5C282DD for ; Thu, 9 Jan 2020 17:00:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9237220661 for ; Thu, 9 Jan 2020 17:00:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=anarazel.de header.i=@anarazel.de header.b="i6cV77nS"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="cxjk8Puo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731464AbgAIRAp (ORCPT ); Thu, 9 Jan 2020 12:00:45 -0500 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:50517 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731320AbgAIRAo (ORCPT ); Thu, 9 Jan 2020 12:00:44 -0500 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.nyi.internal (Postfix) with ESMTP id 55153214DB; Thu, 9 Jan 2020 12:00:43 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute5.internal (MEProxy); Thu, 09 Jan 2020 12:00:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=anarazel.de; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm3; bh=hcgptnGOQIZIIhyQtpsCyNNyBT2 /xi/KbtsQbbxl1sM=; b=i6cV77nSAvfaICP1k5kwwfHKme5Q8VKHkYjvdeDpe0o nS8qxapgapFts3bc/uQ86OmWjwKa5yulhHZ9+L69WgwC93cot5MryFjhWCrFD/Xd ZgdEDf/R700vhY5ZLZvijQMkEIt28TLIYXR0gMpzJdX1ptSGCp52HoytAVcm2qzv zwqcqnmpAgUDUGZ/VwGYTZnwWagNnW9Mfs0tpIXLdVyW8JTfjOZNrXditk73sI8t wtIO1HJMCTS5JFI7a514Gy4SRgaVuy0u3w6YcfjWGp2R603vzZhQ7vvTuqMiINUh xEE9x4n4Mhe6L8Spn+aeOcjaUfShy8+zbCDU9BWdryA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=hcgptn GOQIZIIhyQtpsCyNNyBT2/xi/KbtsQbbxl1sM=; b=cxjk8PuoU8UAskb2Z2/zjc Z0MkVcdGI7jx5d1ehOUaFu9u2RQquQOdE6TdiVrN0AE1yKlzLYfo2TtzXtqoM/ow ihn87wsNsspehcHIBZCb35O7iKjku/A4O/9byOccNllNEuCfnI1pzQmpj2oCTdhU H4uQnBtuDoly+cM5vIjDmM10DAsrGNrhLMex4dEtFgRoEGlEPKypwZqRAGUX0Pgz X1mSN/rw88fT5OIlHPhoesKVspmeTFdn9LhKdaylwwPfMPplXtolI60H7ADb0GXC +xlCVTp1QEZf1Je7Hlerd89G/J8fZv1OLgGgJHUm84VkD690Oyyw/h9/STNqIWLg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedufedrvdeiuddgiedtucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpeetnhgurhgv shcuhfhrvghunhguuceorghnughrvghssegrnhgrrhgriigvlhdruggvqeenucfkphepie ejrdduiedtrddvudejrddvhedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegrnhgurhgv shesrghnrghrrgiivghlrdguvgenucevlhhushhtvghrufhiiigvpedt X-ME-Proxy: Received: from intern.anarazel.de (c-67-160-217-250.hsd1.ca.comcast.net [67.160.217.250]) by mail.messagingengine.com (Postfix) with ESMTPA id B960830602DE; Thu, 9 Jan 2020 12:00:42 -0500 (EST) Date: Thu, 9 Jan 2020 09:00:41 -0800 From: Andres Freund To: Jiri Olsa Cc: linux-kernel@vger.kernel.org, Jiri Olsa , Andi Kleen , Arnaldo Carvalho de Melo , Alexander Shishkin , Michael Petlan , Namhyung Kim , Peter Zijlstra , stable@vger.kernel.org Subject: Re: [PATCH] perf c2c: Fix sorting. Message-ID: <20200109170041.wgvxcci3mkjh4uee@alap3.anarazel.de> References: <20200109043030.233746-1-andres@anarazel.de> <20200109084822.GD52936@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200109084822.GD52936@krava> Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Hi, On 2020-01-09 09:48:22 +0100, Jiri Olsa wrote: > On Wed, Jan 08, 2020 at 08:30:30PM -0800, Andres Freund wrote: > > Commit 722ddfde366f ("perf tools: Fix time sorting") changed - > > correctly so - hist_entry__sort to return int64. Unfortunately several > > of the builtin-c2c.c comparison routines only happened to work due the > > cast caused by the wrong return type. > > > > This causes meaningless ordering of both the cacheline list, and the > > cacheline details page. E.g a simple > > perf c2c record -a sleep 3 > > perf c2c report > > will result in cacheline table like > > ================================================= > > Shared Data Cache Line Table > > ================================================= > > # > > # ----------- Cacheline ---------- Total Tot ----- LLC Load Hitm ----- ---- Store Reference ---- --- Load Dram ---- LLC Total ----- Core Load Hit ----- -- LLC Load Hit -- > > # Index Address Node PA cnt records Hitm Total Lcl Rmt Total L1Hit L1Miss Lcl Rmt Ld Miss Loads FB L1 L2 Llc Rmt > > # ..... .................. .... ...... ....... ....... ....... ....... ....... ....... ....... ....... ........ ........ ....... ....... ....... ....... ....... ........ ........ > > # > > 0 0x7f0d27ffba00 N/A 0 52 0.12% 13 6 7 12 12 0 0 7 14 40 4 16 0 0 0 > > 1 0x7f0d27ff61c0 N/A 0 6353 14.04% 1475 801 674 779 779 0 0 718 1392 5574 1299 1967 0 115 0 > > 2 0x7f0d26d3ec80 N/A 0 71 0.15% 16 4 12 13 13 0 0 12 24 58 1 20 0 9 0 > > 3 0x7f0d26d3ec00 N/A 0 98 0.22% 23 17 6 19 19 0 0 6 12 79 0 40 0 10 0 > > i.e. with the list not being ordered by Total Hitm. > > > > Fixes: 722ddfde366f ("perf tools: Fix time sorting") > > Signed-off-by: Andres Freund > > Cc: Jiri Olsa > > Cc: Andi Kleen > > Cc: Arnaldo Carvalho de Melo > > Cc: Alexander Shishkin > > Cc: Michael Petlan > > Cc: Namhyung Kim > > Cc: Peter Zijlstra > > Cc: stable@vger.kernel.org # v3.16+ > > --- > > tools/perf/builtin-c2c.c | 10 ++++++---- > > 1 file changed, 6 insertions(+), 4 deletions(-) > > > > diff --git a/tools/perf/builtin-c2c.c b/tools/perf/builtin-c2c.c > > index e69f44941aad..f2e9d2b1b913 100644 > > --- a/tools/perf/builtin-c2c.c > > +++ b/tools/perf/builtin-c2c.c > > @@ -595,8 +595,8 @@ tot_hitm_cmp(struct perf_hpp_fmt *fmt __maybe_unused, > > { > > struct c2c_hist_entry *c2c_left; > > struct c2c_hist_entry *c2c_right; > > - unsigned int tot_hitm_left; > > - unsigned int tot_hitm_right; > > + uint64_t tot_hitm_left; > > + uint64_t tot_hitm_right; > > that change looks right, but I can't see how that could > happened because of change in Fixes: tag > > was the return statement of this function: > > return tot_hitm_left - tot_hitm_right; > > considered to be 'unsigned int' and then converted to int64_t, > which would treat negative 'unsigned int' as big positive 'int64_t'? Correct. So e.g. when comparing 1 and 2 tot_hitm, we'd get (int64_t) UINT_MAX as a result, which is obviously wrong. However, due to hist_entry__sort() returning int at the time, this was masked, as the int64_t was cast to int. Thereby again yielding a negative number for the comparisons of hist_entry__sort()'s result. After hist_entry__sort() was fixed however, there never could be negative return values (but 0's are possible) of hist_entry__sort() for c2c. I briefly looked for places outside of c2c for similar issues in hist_entry comparison routines, but didn't find any. Greetings, Andres Freund