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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 586F0C433EF for ; Tue, 29 Mar 2022 14:16:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237801AbiC2OSH (ORCPT ); Tue, 29 Mar 2022 10:18:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237585AbiC2OSG (ORCPT ); Tue, 29 Mar 2022 10:18:06 -0400 Received: from mail-wr1-x42d.google.com (mail-wr1-x42d.google.com [IPv6:2a00:1450:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BAF4E389A for ; Tue, 29 Mar 2022 07:16:22 -0700 (PDT) Received: by mail-wr1-x42d.google.com with SMTP id u16so25049402wru.4 for ; Tue, 29 Mar 2022 07:16:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=ApZndiwJNJZl0SipZbpbx1y3pSTDGsI2OYESYfSgmRI=; b=szLF4na2paIg1s4iZdbmJ8mCpPYLmW48qK3wdxRxIPWBTrhi0gaLJ1W1LAdCGuoVTA p8eWWU9aJBFQbKIsvCydcMEpWAQZ+XWzoxxSi8UCOZGPTCFHnM1ry3jCNQIyyWZrT9dK 9nQL8s7AujVQyG0XZkaj8mW7qtEV+FyPmNNcnFZ9CSPz0Y9zUIyPiy5ViC8OfbMSdBly 4Jo6W73cr5FpJlTlcYbqFY4vkpk2Op+vUNsllbVrQle/JWpjB6MWoQewc9ySt/RthV1D N/koCU1lPJthZdyVJbuh3RBJv8PkGy6KjvZiRcBXe3wMHPdKo03yAiYyuN2s+qN181D7 ZXZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=ApZndiwJNJZl0SipZbpbx1y3pSTDGsI2OYESYfSgmRI=; b=StnNOZL+g4/w5+OCnTLJ/0jBZCpaVAW+zYsO2YG58t8FAXWwY1sCCbhjpVX4ijJ7lA tZnbNL35O5AuRqiFPTGEkmMiVu2sBo40A++QLvM3+NoMMzs0oKqU0ZRg+l23it+tRiS6 /tCIyiV6Tcz1loe3d1hpZSS9TSJezR0/bFpzcZhUW7pAsvzrIXlIqhk/j5q5RqzPhEvS YnxjTln5sX4dUBJCSTn34E2vp+5eNxBLH4T9gt4MsEQLdfKW3vjw7fbp5bS9HA7uj1ji NeIFsp1n+3KZ3EPh5xx2H4mVsfWD7Gc8d1BVAbNUCI1/3+FsjhNmY2fu3zNB3qcQBB/F gAKQ== X-Gm-Message-State: AOAM532raJgZ/IMn/PXVtMpnVuohw6F9FbVabJYuPwtfx7vmlj457Z4I q0ecZqNzQ+wPxfhfYabzz9ykqg== X-Google-Smtp-Source: ABdhPJzoCt9FnR7gH0jRnO98pHDPc8I6nVcblqa6U4wrKW0EyTEOFSa98+n1XELxAHldPTuzcpRVOQ== X-Received: by 2002:a5d:58f2:0:b0:205:7f1b:9dc7 with SMTP id f18-20020a5d58f2000000b002057f1b9dc7mr31327403wrd.109.1648563375739; Tue, 29 Mar 2022 07:16:15 -0700 (PDT) Received: from google.com (110.121.148.146.bc.googleusercontent.com. [146.148.121.110]) by smtp.gmail.com with ESMTPSA id n15-20020a05600c500f00b0038cfb1a43d6sm2371826wmr.24.2022.03.29.07.16.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Mar 2022 07:16:14 -0700 (PDT) Date: Tue, 29 Mar 2022 16:16:11 +0200 From: "Steinar H. Gunderson" To: Adrian Hunter Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] perf intel-pt: Synthesize cycle events Message-ID: References: <52903e58-e74c-5ea0-36b4-277ea3610af4@intel.com> <371faf0d-f794-4a2e-0a1c-9d454d7c8b12@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 29, 2022 at 02:31:14PM +0200, Steinar H. Gunderson wrote: > int64_t _sort__sym_cmp(struct symbol *sym_l, struct symbol *sym_r) > { > if (!sym_l || !sym_r) > return cmp_null(sym_l, sym_r); > > if (sym_l == sym_r) > return 0; > > if (sym_l->inlined || sym_r->inlined) { > int ret = strcmp(sym_l->name, sym_r->name); > > if (ret) > return ret; > if ((sym_l->start <= sym_r->end) && (sym_l->end >= sym_r->start)) > return 0; > } > > if (sym_l->start != sym_r->start) > return (int64_t)(sym_r->start - sym_l->start); Even fixing <= to <, I do get nonsensical results like an inlined (and very small) destructor taking 50%+ of CPU time, and having a huge call chain under it. It largely goes away (I'm not sure if it's perfect) if I remove the entire if (sym_l->inlined || ... branch, but I guess it's there for a reason. Thinking about it, I wonder if this code breaks the entire tree invariant of comparison being transitive. If left _or_ right is inlined, it compares them by name, but if not, it compares them by address. So you can have three symbols A, B (inline) and C, where A < B (on name), B < C (on name) but C < A (on address; assuming C has a lower start address than A). That doesn't look good to me. I'm wondering if the right fix would be something like replacing the entire if with something like if (sym_l->inlined && sym_r->inlined && strcmp(sym_l->name, sym_r->name) == 0) && ) { return 0; } but I'm not sure. /* Steinar */