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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 4B97BC3F2CD for ; Mon, 23 Mar 2020 16:59:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0FF6520658 for ; Mon, 23 Mar 2020 16:59:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20150623.gappssmtp.com header.i=@networkplumber-org.20150623.gappssmtp.com header.b="wPwACC9/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727572AbgCWQ71 (ORCPT ); Mon, 23 Mar 2020 12:59:27 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:44580 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727164AbgCWQ70 (ORCPT ); Mon, 23 Mar 2020 12:59:26 -0400 Received: by mail-pf1-f196.google.com with SMTP id b72so7758881pfb.11 for ; Mon, 23 Mar 2020 09:59:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:subject:message-id:mime-version :content-transfer-encoding; bh=0Yz3aCtfs/NmJpk29XMbsItf5utDQd9JiRR8EbPIQxE=; b=wPwACC9/U3hgmHfDEX/maP0v/3kGU5BlP4UJu+jRZqzcMPJ5AcHAsbNRRBeCu4AEnS mWqrxTdvHjhCg2JtZvvv+GFR4wxnmrnHdTNUYDcywVsOkYUMonVDNJlWNO2gFBhDQnFR 5NUos6C9yEvhCTO6tu00VxEip5/IctaGTam9655bLoe+PJHcR436cmiamXaLEzCuJtpU 1K6d0BYPRAG6ttOyVYck6guZJ6/yAw+DEbQf58Hk7V7WgLdd19sd2ZiTfCC+BDgZ1x7m nfBlz5vTH/j0rJi6itHIs+e28Vipc30/4bX02+KV4Y1Dcmq8qjdJZXJjcirRt8pkisNW rPqg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:mime-version :content-transfer-encoding; bh=0Yz3aCtfs/NmJpk29XMbsItf5utDQd9JiRR8EbPIQxE=; b=WIo/0fYahXkOtp1zzSBS5Qi07P3KDl9dtflWvn2RXybWxTTYaf9kvuDzx0ml8SaCeN FPfftdhlnRdU8ndUL/DilPHFH87zE6dMZ/GvOdsMHjGT+5SAtooPuvsFSHtuYPhxcAwm d3IL8YL7TPc04FVoHmTRzRu7lN++WsOFHDzkhepEM0ssCQv5AfO28HZ0YtBV5b7O/HO4 NlQdWZC6ZQ3ObLgPB+qYfo3IOKl96sglComW6tDbXno852iVdruuwSS1Q9V6q2vTCK71 0S++7DslvAydyXFV+znBeEu1L4YpvCjA2jTbUjEaRk2KKGDMtqMBRTnia+iYqhR8nxJ1 GbJQ== X-Gm-Message-State: ANhLgQ342e6E3XIXzRMay6a4XPglL/ogXt4yGq8t+JjwsN/FXwGb8fnj AWfTruJrtXQBuQb+j6DpnxKBuFclf0Y= X-Google-Smtp-Source: ADFU+vtXeKcQWLY+dA2JLgzKrkbYlsnbb6px0eh+Tw2qRtCcEt0hfKTwy0N7ahGHcBPaoBsP8MNyUg== X-Received: by 2002:a63:1003:: with SMTP id f3mr23221873pgl.450.1584982763979; Mon, 23 Mar 2020 09:59:23 -0700 (PDT) Received: from hermes.lan (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id q13sm12570922pgh.30.2020.03.23.09.59.23 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Mar 2020 09:59:23 -0700 (PDT) Date: Mon, 23 Mar 2020 09:59:18 -0700 From: Stephen Hemminger To: netdev@vger.kernel.org Subject: Fw: [Bug 206919] New: Very bad performance of sendto function Message-ID: <20200323095918.1f6d6400@hermes.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org There maybe something here but probably not. Begin forwarded message: Date: Sun, 22 Mar 2020 11:22:46 +0000 From: bugzilla-daemon@bugzilla.kernel.org To: stephen@networkplumber.org Subject: [Bug 206919] New: Very bad performance of sendto function https://bugzilla.kernel.org/show_bug.cgi?id=206919 Bug ID: 206919 Summary: Very bad performance of sendto function Product: Networking Version: 2.5 Kernel Version: 5.4.13 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Other Assignee: stephen@networkplumber.org Reporter: bernat.arlandis@gmail.com Regression: No Created attachment 288007 --> https://bugzilla.kernel.org/attachment.cgi?id=288007&action=edit Sysprof capture file Hi, I have a case where the sendto function is slowing down the software I'm trying to use. Sysprof capture file attached. It's probably being called at a high frequency and the __netlink_dump_start function spends a lot of time in the mutex lock, then also in the netlink_dump call. This is causing the threads calling the function to stall. At least this is my interpretation of the profiling session. I don't have any knowledge about the way networking code works. I'd like to know if the flaw is in the user-space software or in the kernel. Can I provide any more info or do some test to help determine what's happening? I'd like to help fix it. My NIC: Intel Corporation I211 Gigabit Network Connection (rev 03) My system: Debian 10 with kernel 5.4.13. Thanks. -- You are receiving this mail because: You are the assignee for the bug.