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=-5.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_NEOMUTT autolearn=unavailable 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 2EE3EC31E4B for ; Fri, 14 Jun 2019 13:50:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02F0620850 for ; Fri, 14 Jun 2019 13:50:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=toxicpanda-com.20150623.gappssmtp.com header.i=@toxicpanda-com.20150623.gappssmtp.com header.b="xvG8BKrs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728784AbfFNNuL (ORCPT ); Fri, 14 Jun 2019 09:50:11 -0400 Received: from mail-qt1-f195.google.com ([209.85.160.195]:42593 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728826AbfFNNuK (ORCPT ); Fri, 14 Jun 2019 09:50:10 -0400 Received: by mail-qt1-f195.google.com with SMTP id s15so2477859qtk.9 for ; Fri, 14 Jun 2019 06:50:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Rdet0I+UWXME2YtJOPcri6B791wkgPbT0ODn/e0NNDE=; b=xvG8BKrsNAVh/vCgi+a/I1WY/69P6du33JCLdiidof2V0IfXffFjeJiQhuvNbYv8Hb POIBevYAmKF2ZByQmirjeiMx1gkNMeiM85Z6/HtgCH0trjaz6oG9cE5s+cG1k9XmxdsA jpsOdJwKw5qG+wPH48dKjymEbS6O2XDcPedhF3KcoyecbH/QNxglXXctQjWGu/SR09+j 3KzU8bLFH7PuOVeqXWOfWsvhSvJ3IMxABCbhnNq0itq+E2Hh/FnLEfzLunbj8HYnXL0p wfStLgLLMwK34P3zkkOb8twGzdXLL1kOqPqWVPuYUxcV5CXpjnabkhrJMBBeIoS78Axp EvqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=Rdet0I+UWXME2YtJOPcri6B791wkgPbT0ODn/e0NNDE=; b=s8Gpv3cCdgQ+cmYw7dKOxHTuKfwuHWzl85e/ZNzjrTjJvCquVnYmENFtsPX1FwPfPE 7RavbuSBWum3bps0OpuHUOLHTURLD3bnaFT9GfSBePVGpP/HqEyZiTRspXmLJkxs/bib R1wAzSR9uTD5cvlJVFdNR3bXnflpzltZn59zk5BA3qIEr8LBZZipL3SiADiOsPkhQYth AvHuAPANkG+yRdEVf8bYvNDcU5QulFr0aXH+3fD/4PF09t4mVC3/HKYOBAP3bzoDH4YF /MgXhs4jgJsW6WiOqGcJuGFB+ES3keWJmTvnimPNlXGfeakdpWbNixKYSCrSrDNVj/zL ECEA== X-Gm-Message-State: APjAAAUzwvJ813/z983JbTTR48Ll36XadB6FSruFrC9szmkw/rLd+JQu 3lw/nyRZiaYjWIRAKt4IJE07fQ== X-Google-Smtp-Source: APXvYqyDDDI8puKpDK9WlTUrJOIA8FGHM2Hd0M/1HQJqRcBRsNVkseNvcj5yoYx4W5gNyPaN5wFsIQ== X-Received: by 2002:aed:224d:: with SMTP id o13mr77466543qtc.56.1560520209532; Fri, 14 Jun 2019 06:50:09 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::a658]) by smtp.gmail.com with ESMTPSA id d38sm1670624qtb.95.2019.06.14.06.50.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 14 Jun 2019 06:50:08 -0700 (PDT) Date: Fri, 14 Jun 2019 09:50:07 -0400 From: Josef Bacik To: Tejun Heo Cc: dsterba@suse.com, clm@fb.com, josef@toxicpanda.com, axboe@kernel.dk, jack@suse.cz, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 7/8] Btrfs: use REQ_CGROUP_PUNT for worker thread submitted bios Message-ID: <20190614135006.ug5qgpc5uocuip6b@MacBook-Pro-91.local> References: <20190614003350.1178444-1-tj@kernel.org> <20190614003350.1178444-8-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190614003350.1178444-8-tj@kernel.org> User-Agent: NeoMutt/20180716 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Jun 13, 2019 at 05:33:49PM -0700, Tejun Heo wrote: > From: Chris Mason > > Async CRCs and compression submit IO through helper threads, which > means they have IO priority inversions when cgroup IO controllers are > in use. > > This flags all of the writes submitted by btrfs helper threads as > REQ_CGROUP_PUNT. submit_bio() will punt these to dedicated per-blkcg > work items to avoid the priority inversion. > > For the compression code, we take a reference on the wbc's blkg css and > pass it down to the async workers. > > For the async crcs, the bio already has the correct css, we just need to > tell the block layer to use REQ_CGROUP_PUNT. > > Signed-off-by: Chris Mason > Modified-and-reviewed-by: Tejun Heo > --- Reviewed-by: Josef Bacik Thanks, Josef