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 1C0D9A0032 for ; Fri, 24 Jun 2022 17:01:31 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 9D53E4069D; Fri, 24 Jun 2022 17:01:30 +0200 (CEST) Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) by mails.dpdk.org (Postfix) with ESMTP id 7C81E400EF for ; Fri, 24 Jun 2022 17:01:29 +0200 (CEST) Received: by mail-pj1-f53.google.com with SMTP id p3-20020a17090a428300b001ec865eb4a2so6049060pjg.3 for ; Fri, 24 Jun 2022 08:01:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=koI/+I/F6EJ6AgsF3XR44OalVFUQMgiVkMHmwqcWvu8=; b=5k5FwjqRHWMbCk0qS7s2cc7RRAvnWwgt6WyWdIgRj2mXoN20qWplmwZNuAufuJesop xrZMtO+S7XrK+o9zG21LeGpUV/WGG/PQGqeRgsQllQq9m+p2QHI2e68Sa7Rk6xZDrb8J MKcWQFfNXq4krJhLq3xWcaPFWyQs+dWA/bKp/NkcG05MHEiNnd9JL65P53zHaSkLjjPL nJvV4cqiH90cuxKG9ad7+16jnagZDy/vVfWVt5EkvJnw3aeapRiLP44h8ow+ex5ly6qI bTWfZRjkBHiFmVZBZ/25KcuYOtWvSNqiiuqueS0zW18SuDwBF5AuBQBAJaDJkjs3jPNR PSMQ== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=koI/+I/F6EJ6AgsF3XR44OalVFUQMgiVkMHmwqcWvu8=; b=JddwJJr2wjwoOkzeeX7PYG76evxZJ12GYfvcmkCgoL6ligP8jHsy0dlYek/mta6J/z e7JyNpYPc6TgAjn1VMAuAO2j4dkflWahU01miUdL53OpGQ+4XDuZCJvYAZVAP8LFhgki EBmK4GBFuDpzOBzgYWdinoVSBKsKseMI9hgRQkOEF+Zv4mf42cv0o7/7S7vmPdjim+++ uEJNqu9HOge2jGuki4y/z+Gw8pyiXVDmDtph90m7VamB54Heanxx88ugDjI1A+EQIhMF rB/3G0fa2gXcehbvsmomEjt2iAQj6j5A3OXwXbawmM6D0Iovnu5nM2bk4aWyVOX3tWxy 732A== X-Gm-Message-State: AJIora+rmILn87DM+Kh20R+5FYQT+t9rgGkU1KJVD6mN4jK5JfrepOjv gaDuyC/u3FbfTk3iRTnPF0//KQ== X-Google-Smtp-Source: AGRyM1tmb4++gScwVXYF4J8Dcdtu4LH2I3JeEF1FodFwO3VU6RVYr0FSdLLVrUk07BAHeupDVLNiZQ== X-Received: by 2002:a17:903:1208:b0:168:e42f:acf9 with SMTP id l8-20020a170903120800b00168e42facf9mr43629990plh.165.1656082888566; Fri, 24 Jun 2022 08:01:28 -0700 (PDT) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id v4-20020a170902b7c400b0016223b5d228sm1893694plz.288.2022.06.24.08.01.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Jun 2022 08:01:27 -0700 (PDT) Date: Fri, 24 Jun 2022 08:01:24 -0700 From: Stephen Hemminger To: Carsten Andrich Cc: users@dpdk.org Subject: Re: Large interruptions for EAL thread running on isol core Message-ID: <20220624080124.244a01a9@hermes.local> In-Reply-To: <9a95a560-c7c6-d4fa-1041-836fa400f497@tu-ilmenau.de> References: <9a95a560-c7c6-d4fa-1041-836fa400f497@tu-ilmenau.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org On Thu, 23 Jun 2022 21:03:49 +0200 Carsten Andrich wrote: > 2. Use real-time priority (SCHED_FIFO w/ priority 99) for the DPDK > threads and > echo -1 > /proc/sys/kernel/sched_rt_runtime_us > to disable the runtime limit. With the runtime limit in place, the > SCHED_FIFO performance will be significantly worse than SCHED_OTHER. This can cause major issues if application is normal DPDK application (never does system calls). If an interrupt or other event happens on your isolated CPU, the work that it would do in soft irq is never performed. FIFO has higher priority than kernel threads. This can lead to mystery lockups from other applications (reads not completing, network timeouts, etc). In any semi-recent kernel using SCHED_NO_HZ_FULL will keep clock ticks from happening on the isolated cores.