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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 858B4C433FE for ; Wed, 5 Oct 2022 00:22:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B64546B0072; Tue, 4 Oct 2022 20:22:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AED586B0073; Tue, 4 Oct 2022 20:22:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 98DF56B0074; Tue, 4 Oct 2022 20:22:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 82C0F6B0072 for ; Tue, 4 Oct 2022 20:22:06 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 4AB43A0A1C for ; Wed, 5 Oct 2022 00:22:06 +0000 (UTC) X-FDA: 79984993452.29.780A6A5 Received: from mail3-166.sinamail.sina.com.cn (mail3-166.sinamail.sina.com.cn [202.108.3.166]) by imf23.hostedemail.com (Postfix) with ESMTP id 0DBF614001C for ; Wed, 5 Oct 2022 00:22:03 +0000 (UTC) Received: from unknown (HELO localhost.localdomain)([114.249.58.228]) by sina.com (172.16.97.23) with ESMTP id 633CCDCE000108FF; Wed, 5 Oct 2022 08:20:32 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com X-SMAIL-MID: 88771954922788 From: Hillf Danton To: John Stultz Cc: LKML , linux-mm@kvack.org, "Connor O'Brien" , Qais Yousef , Peter Zijlstra , Steven Rostedt Subject: Re: [RFC PATCH v4 2/3] sched: Avoid placing RT threads on cores handling long softirqs Date: Wed, 5 Oct 2022 08:21:49 +0800 Message-Id: <20221005002149.1876-1-hdanton@sina.com> In-Reply-To: References: <20221003232033.3404802-3-jstultz@google.com> <20221004013611.1822-1-hdanton@sina.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664929326; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oAXgDScoJR9RQtP6vPkC2sH+E7xewmAg5+VX/BNBOuE=; b=ANJyagOHy/85aekMXEjUE1i3L7VyeA9cCRwY8jLikDlQ65Rr2gEm2j57h90s1diTLBNM/b Y7+BpSmvZsp8EBGCtkFi/mcdBhGWnBIui+9sUBTzdoDjinweRJbsemeLF9MrfUUmhTQrlQ aDMwNdNHQ26sIlELYn7RZL7zOBYRquE= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf23.hostedemail.com: domain of hdanton@sina.com designates 202.108.3.166 as permitted sender) smtp.mailfrom=hdanton@sina.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664929326; a=rsa-sha256; cv=none; b=kjb88y1SrXwfR9ShORxx79qHyJWB9d9E5XXy0aOvpb5rXGUlE2BtwJ4IC51Q2o5TRFI3jN Skcj/sFXYvZU8F64x8ThrP7KGCCclUexDQSEUDzR+jR5tXjCbolEPEe/LlQeGcZXbas2Ch yHiCI4fo32aoQZkmvc1IN1yU9OZ9abc= X-Rspamd-Queue-Id: 0DBF614001C Authentication-Results: imf23.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf23.hostedemail.com: domain of hdanton@sina.com designates 202.108.3.166 as permitted sender) smtp.mailfrom=hdanton@sina.com X-Rspam-User: X-Rspamd-Server: rspam10 X-Stat-Signature: wddpunqkfgr81tsxzbzmf3r583eyxrxj X-HE-Tag: 1664929323-559767 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000011, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 3 Oct 2022 19:29:36 -0700 John Stultz > > Why would ksoftirqd preempt the rt task? > For example the kthread becomes sensitive to latency.