From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-x835.google.com (mail-qt1-x835.google.com [IPv6:2607:f8b0:4864:20::835]) by sourceware.org (Postfix) with ESMTPS id 19D4E3858C83 for ; Mon, 27 Mar 2023 14:38:47 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 19D4E3858C83 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-qt1-x835.google.com with SMTP id r5so8762013qtp.4 for ; Mon, 27 Mar 2023 07:38:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679927926; h=content-language:thread-index:mime-version:message-id:date:subject :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Kl8K0/8kgPMuhzUm+IJmDuM2OjjEzB0wGi92XfyhORs=; b=aj/fS7oekWGnYiaHaEn5dMTOIVtERLml1qyI/E+5hZAnrzvR5vQBaChz3ieLqtSR8a 1GZOQ0ZMLsQjH85rl+gWZShlKHtvvb1V6WzhBLgw7qe+PsOPdfMqzY1MDOKYAOvL4YlV 1v2Bs5DacitX4GFDQcOqlt3a0xkJy3TGH68IpunpK5JaTfEMMvwujxMjujz9RqGNI8lS bVarKlmA1f8i3BTRcsXkcVddG+bBqEWNmcASqOe1qBE92/Ak2YXuICHOqw6a0rkIbhBf eMle/vS7cQSCCpv9Tim+ccj6vXUu8UIUvj7g6B+RkK9H5FwIfm7GnM+0C90NkD03+Ai+ nPBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679927926; h=content-language:thread-index:mime-version:message-id:date:subject :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Kl8K0/8kgPMuhzUm+IJmDuM2OjjEzB0wGi92XfyhORs=; b=1298jFccl/j8nrEFhgzbrmdRkyodMtT05o/Zer/5wRy5YHXy7FnXTGEAPGRI9ndFi3 42DMyLdYquWqfxvOZ5EUYl7vGx5IOdkB00PgqNtC3PlcTxMb7ymN/DFHx0LGvmn6utMr yvp/owlVF+WCyLi6ACDJHcdVDf8b3uRQvuvSE+haPdKkKyMZGrRgXlE3n1M1xcpqaqK0 I5SRrHIRu3/o4S6+Ns+T5ac8MpSdOtU2Q5Z6rkUjhYJBzlutwjougjE4hgniI28USmo2 yLTqLxIk05w0aeHkY1CDv5TWg/prGQoR/CPkAUYeL/u5zF5YLxs8x8eGTsh5w9e3KotM wX0g== X-Gm-Message-State: AO0yUKVGPga4t6evkbUqB4/s99vRjBaaFr7PBYfslf/2Xj7I3GHiwoSQ 5v/ug4eqZlB7rfZ0FjejwIfarv1Q6z4HrORF X-Google-Smtp-Source: AK7set8/KxPsgfRVqhVa1nPSxNgq7NeEG6yPBbzAAgc6/ZhIMDUg69R/D1rT0lw7gNpZ2hMSdYxA+A== X-Received: by 2002:ac8:5f96:0:b0:3b8:3a7c:d208 with SMTP id j22-20020ac85f96000000b003b83a7cd208mr16858241qta.34.1679927926038; Mon, 27 Mar 2023 07:38:46 -0700 (PDT) Received: from DESKTOP819AQCO (c-73-186-197-163.hsd1.ct.comcast.net. [73.186.197.163]) by smtp.gmail.com with ESMTPSA id 139-20020a370591000000b00745a78b0b3asm12836143qkf.130.2023.03.27.07.38.45 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Mar 2023 07:38:45 -0700 (PDT) From: To: Subject: feedback on gprofng Date: Mon, 27 Mar 2023 10:38:44 -0400 Message-ID: <001a01d960b9$d56bfa60$8043ef20$@gmail.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001B_01D96098.4E5B1DB0" X-Mailer: Microsoft Outlook 16.0 Thread-Index: Adlgt6LkBEfJlp8KQ8aaliwyYhtikQ== Content-Language: en-us X-Spam-Status: No, score=1.4 required=5.0 tests=BAYES_50,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Level: * X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: This is a multipart message in MIME format. ------=_NextPart_000_001B_01D96098.4E5B1DB0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit I suggest you have another output from gprofng: (I assume the sampling is on wall-clock time, so it has visibility into I/O.) Let the user choose a small number N, like 10 or 20, and then select N stacks at random (with source code line info) and display them, in a tree or in raw form. The point is - any performance problem consists of activity that isn't necessary, and if it accounts for fraction F of time, then it will show up on NF samples. High precision of measurement is not necessary, but precision of insight is. If there are multiple threads, let each sample be from all running threads at the same time, so the user can see which threads are waiting for which other threads at the point in time. Let me know if this makes sense, or maybe you've already done it. Thanks, Mike Dunlavey P.S. I've been advocating this for years on StackOverflow. People who've tried it agree that it works. I've also got a YouTube video about it. ------=_NextPart_000_001B_01D96098.4E5B1DB0--