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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CEC84C433F5 for ; Fri, 7 Jan 2022 14:13:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239127AbiAGONN (ORCPT ); Fri, 7 Jan 2022 09:13:13 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:33275 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239025AbiAGONN (ORCPT ); Fri, 7 Jan 2022 09:13:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1641564792; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2L4YEi0aDoHLNeQF/we9qhhc3irCTkuMiMi3Iny+wp0=; b=RXWEO5kUivo8zJtXAcXpT2aKXarUSQer69rrTu+/tOFjSWSuxIpwsePdZ37R5b63KTbQpf t1DZA8HOhtEsjYEj3NcBweIU3jec3cYa0OYEDB6xOoM9iCgBUlA+mIuEIz01FzRU+9NGSM dATu6Z2qlAjGucELUaTB927AvrSVuZw= Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-479-g5tYbWFmPgqWI2X5h5tWdg-1; Fri, 07 Jan 2022 09:13:10 -0500 X-MC-Unique: g5tYbWFmPgqWI2X5h5tWdg-1 Received: by mail-qv1-f71.google.com with SMTP id gf14-20020a056214250e00b00411ba2ba63dso4867934qvb.21 for ; Fri, 07 Jan 2022 06:13:10 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:to:references:from:subject:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=2L4YEi0aDoHLNeQF/we9qhhc3irCTkuMiMi3Iny+wp0=; b=cdXuyyvE3NsX420qDDn++AjnbyhaGabdVJIxHlhdfDJZRxNQVnWNlCIEgdcfmWs/6G F1cnoKiklzAFyy0aj07xWFdLZwJBbXfOd3JRx2AScL0+AFLHuOpXmHxbLBolzzTcsfrc CXy8QI4GtLhgduNTcx/tjD5WNrjBXSVJU0LWU2iXTN3gOcWXNbswQUE9CMHyCRyKRSNY AgdoTnu7pzjNPAl18fr5IcOs1eJN63eIbuuLIiWkRTqWDvXIRYXZm1Icyiru6osSINsK thz/lR8cMGBt7DbkqKUlNvrCMAOfCRDieB6H6RkNTxeHcl29uHK5O9kvTQQkihlE9Ula BRYw== X-Gm-Message-State: AOAM530VeSkWw9LXWEoIKEjL1/IfKxfoZsDxE0iINSshIx4zIDcGB60y VmZm0CSlMi2VKNxG2wWLr8RyeU4Cwd+L9s+ki/40UQIK47++9ki8k1ATE5PwhqMAGioYIv0KHMN TSK7UJwTlyNOtN677zeKL2pXnlA== X-Received: by 2002:a05:620a:4446:: with SMTP id w6mr44672982qkp.273.1641564790441; Fri, 07 Jan 2022 06:13:10 -0800 (PST) X-Google-Smtp-Source: ABdhPJyxpJ4Sg3lAOJt40+fckPzVrfV1SS+laz3cGFmL/vYslY4erIf4p5P2MVtYSxieCu2+92/1+w== X-Received: by 2002:a05:620a:4446:: with SMTP id w6mr44672964qkp.273.1641564790148; Fri, 07 Jan 2022 06:13:10 -0800 (PST) Received: from [192.168.1.9] (pool-68-163-101-245.bstnma.fios.verizon.net. [68.163.101.245]) by smtp.gmail.com with ESMTPSA id o17sm3509317qkp.89.2022.01.07.06.13.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 07 Jan 2022 06:13:09 -0800 (PST) To: David Vernet , live-patching@vger.kernel.org, linux-kernel@vger.kernel.org, jpoimboe@redhat.com, pmladek@suse.com, jikos@kernel.org, mbenes@suse.cz References: <20211229215646.830451-1-void@manifault.com> From: Joe Lawrence Subject: Re: [PATCH] livepatch: Avoid CPU hogging with cond_resched Message-ID: <1f1b9b01-cfab-8a84-f35f-c21172e5d64d@redhat.com> Date: Fri, 7 Jan 2022 09:13:08 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20211229215646.830451-1-void@manifault.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org On 12/29/21 4:56 PM, David Vernet wrote: > For example, under certain workloads, enabling a KLP patch with > many objects or functions may cause ksoftirqd to be starved, and thus for > interrupts to be backlogged and delayed. Just curious, approximately how many objects/functions does it take to hit this condition? While the livepatching kselftests are more about API and kernel correctness, this sounds like an interesting test case for some of the other (out of tree) test suites. Thanks, -- Joe