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 85C0845AD8 for ; Mon, 7 Oct 2024 21:27:23 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 7DC554025C; Mon, 7 Oct 2024 21:27:23 +0200 (CEST) Received: from mail-pf1-f172.google.com (mail-pf1-f172.google.com [209.85.210.172]) by mails.dpdk.org (Postfix) with ESMTP id 6912D4025C for ; Mon, 7 Oct 2024 21:27:22 +0200 (CEST) Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-71e050190ddso931455b3a.0 for ; Mon, 07 Oct 2024 12:27:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1728329241; x=1728934041; 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=VWUF7LWpdiHYPC4k18SbpgVqCvynP+UmA64P+e+BASc=; b=0MBI1MrSPZp3NOWJctaNqMtVyKrv60PSv/crcfMQTyrZvPFRvfn9BeiGLQBvFey1bF +sW6VaH1R2k1PBhNV51jNkTHMMV20B4rrsI90xdyuiYJUTQToc+1A6nlM4/BKHPhZDxP ILdvefE/3BxbO7Bdfeqc1zc3dr7V984jLQBg1pJCpOk0qogAW4TeyOEVGrazG0i2WjlV c74VZJUwyUpdRNt8Z2hO6dGATyABbB0ujPhqAgxyrUsTGoQIihlPaeHFQepspS5dNsAv 58bdLIuyRPp7iD7ZKM7bWlrBpaEJ5AW5gCscm56vKaZCZqS4Y7QPaEWFgzC7+QEN2JPz hoPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1728329241; x=1728934041; 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=VWUF7LWpdiHYPC4k18SbpgVqCvynP+UmA64P+e+BASc=; b=jTYlyArT+oqPqaGv2+jN7fYHJWEyRKrLb4Kmkz8DaSdNLCXX8nB48EPqbOWTK35tMT PznQ5NwBwmsL53hSSiFU+xsdBsSagDI+vP6VOegEzmpIOwK/OiNm0s45N5EqRTDVcQ/W mDyVY+b0bbGrBopsVOGbeydbgAiI4p/JL1hxyZ0V9HaNhlE3KKr2CH0XGCVhJ24HtNY8 U0YPRMF9thSZHZrZ+tYreiJgybFj0kUi4IfInqmDNDFkMmIWRh/7JpyPLkR7V1Ffjnr4 7ivpMRhnqCnuvlIkgHNqWtQTX7d1bnoJJNQ24S4V4g3klJVUFHFtckPP/CUw7Rzcj5/d B/MA== X-Forwarded-Encrypted: i=1; AJvYcCU7Nx81KrWB52yr+miKii+ivG0q3LE7BEdoNDlkeqRsmBtJYnTljh/zOV1W5a91YKEDVR0NE+w=@dpdk.org X-Gm-Message-State: AOJu0YwpKNPqvaC065Bz7W8TaAzNWzpGtg6+d+Ddo80WcXbpemylYoZw /1i4IZo0SKAh5xqNsEAystffSBFN1F9yRvYQzEwtV+Kylwv5hUV44g+rjQUgpFc= X-Google-Smtp-Source: AGHT+IHCzGjOHeDXy447QZ0DO0Pcf5uw1v5HSRqaNkA2gAr7PJQqFA9z1jUC9hcLGKJuzJRRbSy0YA== X-Received: by 2002:a05:6a21:3983:b0:1d5:377c:2241 with SMTP id adf61e73a8af0-1d6df73078fmr22284373637.0.1728329241493; Mon, 07 Oct 2024 12:27:21 -0700 (PDT) Received: from hermes.local (204-195-96-226.wavecable.com. [204.195.96.226]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-71df0ccd04csm4749150b3a.46.2024.10.07.12.27.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Oct 2024 12:27:21 -0700 (PDT) Date: Mon, 7 Oct 2024 12:27:19 -0700 From: Stephen Hemminger To: Thomas Monjalon Cc: dev@dpdk.org, David Marchand , stable@dpdk.org, Morten =?UTF-8?B?QnLDuHJ1cA==?= , Anatoly Burakov , Tyler Retzlaff , Narcisa Vasile , Dmitry Kozlyuk , Konstantin Ananyev , Andrew Rybchenko Subject: Re: [PATCH v6 1/1] eal/unix: allow creating thread with real-time priority Message-ID: <20241007122719.3c34afd3@hermes.local> In-Reply-To: <20231027081158.1358064-1-thomas@monjalon.net> References: <20231024125416.798897-1-thomas@monjalon.net> <20231027081158.1358064-1-thomas@monjalon.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org On Fri, 27 Oct 2023 10:08:52 +0200 Thomas Monjalon wrote: > When adding an API for creating threads, > the real-time priority has been forbidden on Unix. >=20 > There is a known issue with ring behaviour, > but it should not be completely forbidden. >=20 > Real-time thread can block some kernel threads on the same core, > making the system unstable. > That's why a sleep is added in the test thread, > and a warning is logged when using real-time priority. >=20 > Fixes: ca04c78b6262 ("eal: get/set thread priority per thread identifier") > Fixes: ce6e911d20f6 ("eal: add thread lifetime API") > Fixes: a7ba40b2b1bf ("drivers: convert to internal control threads") > Cc: stable@dpdk.org >=20 > Signed-off-by: Thomas Monjalon > Acked-by: Morten Br=C3=B8rup > --- If RT threads are allowed on Linux, then a couple more things are necessary. 1. A functional test, maybe something with two threads exchanging packets ping-pong or something similar and show that the test does not crash or hang the CI system. 2. Sufficient documentation in programmers guide. Probably need a whole chapter on what is RT, when to use RT, and caveats. Make it clear to users that RT is not a faster mode, it is more about working with existing RT applications.