From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 7C13248A8D; Mon, 3 Nov 2025 18:07:22 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 599A2402B7; Mon, 3 Nov 2025 18:07:22 +0100 (CET) Received: from mail-pf1-f171.google.com (mail-pf1-f171.google.com [209.85.210.171]) by mails.dpdk.org (Postfix) with ESMTP id 12B20402B7 for ; Mon, 3 Nov 2025 18:07:20 +0100 (CET) Received: by mail-pf1-f171.google.com with SMTP id d2e1a72fcca58-7833765433cso6122651b3a.0 for ; Mon, 03 Nov 2025 09:07:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1762189640; x=1762794440; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=IIcTTGWaOndMtplpEnppajgwximK8+wChWnLzaIDu+E=; b=NMpvNr/HB6RDR0O5YIf4Mj1ko8dbctazXRDIEGYFsiUpoqpLb8YmcYSqGKlXQEucdC SoA76tDioO5WDoEi3lJ9ZWAm3Aq5kbGRkvQwNgchKwdGCeT4vmkaHcfbEpPAqviPVe4q XCSt0CcyUJqcbCF+A5Uy0jsIEMZ5trUde4gnFZqVeCxRYJpasgg1ozWpqvrnlApU813k CEtoM4GuY3BKnxLutQC+K/os2QZqkMO0eoO/gQ0uMVvKPfjOFk8tKTAmc0+JAmg94Qln Ro8n+LoPH5YQJ+J0wO7hPk1VCxtgnxzwz7lH/H7TcRS6xOTgf6HeQA+pNpi3QNI58SYC 8/hA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762189640; x=1762794440; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=IIcTTGWaOndMtplpEnppajgwximK8+wChWnLzaIDu+E=; b=js9BFRRlE/PyKuEBH22t/FGUeNuvhaYNrnhXmrakVRERA8N0HWF/aZBRoN16mZ55Q6 6pLu3IRU/WHNwwVB/9HXKaA19G5DD1tkxjvYTcbwTxdNIAq4i+QKJwxOtDMjYPra0S8V dVIKhA/FcnD+M+sRaGojrTOIckMNdn2VyFfAh4sFh23hJHO8gcWSna4Z7Cl4Tjy9NZP5 U+43wdHBoQhqHt55B4OapJNvZfPaot43NIUchDhVuapzP5m0yDV7J+F1pEi1udK7TvP3 5NtLzyyvs4crEhBVvb6vROTPFvG4pGON6tDQWHhT9h2zKH64kCxklO0jSsxLY2oi5lTd ilxQ== X-Forwarded-Encrypted: i=1; AJvYcCWOpj4ws409n9OWkdVlaRj9jQ/N5Gv6XRRAo3KpuKckBx2Gk9f24MY74TmKv9/zJrzY0wo=@dpdk.org X-Gm-Message-State: AOJu0YyrrVpaRUwaQRCY99P/d8TELB1uCF9oHy8GrYHEVl+SDurfIxkS njL4e8CqkEw4ieSyRlDRWisrUTDXutqZdyZDpel7wJgwX0eTaUouHyhxNWjxeaEv9Nk= X-Gm-Gg: ASbGncsnjXEyvgTcvuaGNmXwwqCgmi//EjxnnNEGwfFWyuD5XsnJGZ1cvzh26IwmTWt qeYXUldULMDCOGEU5FNbB9mTLS1yspmHZh4ksgxSkTxMjgphwW/NBMHJxqWzrvAE2VoGBU/XylP G3RWu/Jzc5C3e8sDqpiGcdai/tlIedK0dbEbYjIqBbEvdlnlySehi9DxE9w95VRy1GF4n3BHeVB 8RmezfglXctV7UqK62STUfFkqed2vwbon+8ZkTE0vXMGBXdR5A0N5eH8mI/P2Xm/hUmAiB4gYAh et4G4V7itiFlfGPhloVOFGvY/oLe6Lbv4CJ2dneHeLr2s0ssz3I9j3jlkV1N5+HgCiEXuFhi196 c6eAwOeJpBVluBv+6X8dN2WSHIXf+GTPJnHtpnYeQHWkJtkLxrtpp92Pb9pL6/gyDANjHZ0Qkfg 9xO+bzfog9U1g1Bt/UP1qsygwILWnPv+3u9A== X-Google-Smtp-Source: AGHT+IEngt9VovJAILNPCGlO7TZb+oYk30rMXRAYZbbct7v5XW6xUPe6S5PRvBWROkLu3wECe+d8uQ== X-Received: by 2002:a05:6a00:b8e:b0:7a2:8d06:fa0e with SMTP id d2e1a72fcca58-7a77aac1eccmr16256576b3a.26.1762189639914; Mon, 03 Nov 2025 09:07:19 -0800 (PST) Received: from phoenix (204-195-96-226.wavecable.com. [204.195.96.226]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7ab940156fcsm3373868b3a.22.2025.11.03.09.07.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Nov 2025 09:07:19 -0800 (PST) Date: Mon, 3 Nov 2025 09:07:17 -0800 From: Stephen Hemminger To: Wathsala Vithanage Cc: Honnappa Nagarahalli , Tyler Retzlaff , dev@dpdk.org, Ola Liljedahl , vattunuru@marvell.com Subject: Re: [PATCH 1/1] eal: correct memory ordering in MCS lock Message-ID: <20251103090717.2d181d95@phoenix> In-Reply-To: References: <20251023184724.1759497-1-wathsala.vithanage@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On Mon, 3 Nov 2025 09:12:39 -0600 Wathsala Vithanage wrote: > MCS lock is broken, it's just a matter of time it will run into a deadlock. > > drivers/dma/cnxk is a user of MCS lock. I am surprised that a driver would use mcslock. MCSlock is targeted at case of large number of CPU's with lots of contention. It will likely be slower than spinlock or ticketlock for the use case of driver.