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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2FFBC432C3 for ; Wed, 27 Nov 2019 18:07:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C559020874 for ; Wed, 27 Nov 2019 18:07:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C559020874 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=acm.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 382DF6B04DB; Wed, 27 Nov 2019 13:07:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3334D6B04DC; Wed, 27 Nov 2019 13:07:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 24A536B04DD; Wed, 27 Nov 2019 13:07:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0046.hostedemail.com [216.40.44.46]) by kanga.kvack.org (Postfix) with ESMTP id 0BD5C6B04DB for ; Wed, 27 Nov 2019 13:07:50 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id B57B352AA for ; Wed, 27 Nov 2019 18:07:49 +0000 (UTC) X-FDA: 76202840658.16.aunt60_a12af27b2e3e X-HE-Tag: aunt60_a12af27b2e3e X-Filterd-Recvd-Size: 3193 Received: from mail-pl1-f196.google.com (mail-pl1-f196.google.com [209.85.214.196]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Wed, 27 Nov 2019 18:07:49 +0000 (UTC) Received: by mail-pl1-f196.google.com with SMTP id bb5so10124877plb.4 for ; Wed, 27 Nov 2019 10:07:49 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=XaNcptt5JOTBwtSroj+ydYGlh1N5E9Y6StuuTHLWEXM=; b=BgspgSonASXSoR8oMXeCrUaIo8NuhQc1Ia1O2IMPXQpjDxjzySRLUV5nChj5msit1B DgwknsMiUMznKPl/Njtc0b3qeyb+qfMagIES6PhAb54f319EYIAP8Km9K+zmRkGvKitO OE4bW58DwedJRKgiubSn4FU/upIABzVvHpjOX1IHPykMHePhDcpzCNeQm1wPhWn6Jtpv SSbErzAFP36Df9atk451G4tFVXRE1Jh7bynKtFlSw/mRFkyg7+sWz1E9HqjwzT655wXS 2rWTYqi5x/jApY3F/DIwEnSeq3pbacVWguF/g937yDUJosL1CPSewwVn5rZsa/O25CGP afkg== X-Gm-Message-State: APjAAAUY+K6RnJM4IVOqy9bm/x+DTbws/x+G2eDWfQoNj9Fu0rt6dVpI r3TeGxcTDhVJ45F9aXI3z9I= X-Google-Smtp-Source: APXvYqzmi1sTtfjlu4oRd+L662PQX3u2Rr0PhWY+LYbbmu8INk3EProl4I+1RiiEHFx3UH+l9R81dw== X-Received: by 2002:a17:902:7485:: with SMTP id h5mr5458293pll.265.1574878068012; Wed, 27 Nov 2019 10:07:48 -0800 (PST) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:202:4308:52a3:24b6:2c60]) by smtp.gmail.com with ESMTPSA id z6sm7990456pjd.9.2019.11.27.10.07.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 27 Nov 2019 10:07:46 -0800 (PST) Subject: Re: [PATCH] Add prctl support for controlling mem reclaim V4 To: Mike Christie , linux-api@vger.kernel.org, idryomov@gmail.com, mhocko@kernel.org, david@fromorbit.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, martin@urbackup.org, Damien.LeMoal@wdc.com Cc: Michal Hocko , Masato Suzuki References: <20191112001900.9206-1-mchristi@redhat.com> From: Bart Van Assche Message-ID: <24073284-ee53-d22d-dcef-277231283d75@acm.org> Date: Wed, 27 Nov 2019 10:07:45 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191112001900.9206-1-mchristi@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 11/11/19 4:19 PM, Mike Christie wrote: > There are several storage drivers like dm-multipath, iscsi, tcmu-runner, > amd nbd that have userspace components that can run in the IO path. For > example, iscsi and nbd's userspace deamons may need to recreate a socket > and/or send IO on it, and dm-multipath's daemon multipathd may need to > send SG IO or read/write IO to figure out the state of paths and re-set > them up. Reviewed-by: Bart Van Assche