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=-5.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 42883C4360C for ; Thu, 10 Oct 2019 16:53:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E0BA218AC for ; Thu, 10 Oct 2019 16:53:19 +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="dRg8tENL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726783AbfJJQxS (ORCPT ); Thu, 10 Oct 2019 12:53:18 -0400 Received: from mail-qk1-f195.google.com ([209.85.222.195]:35147 "EHLO mail-qk1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726387AbfJJQxR (ORCPT ); Thu, 10 Oct 2019 12:53:17 -0400 Received: by mail-qk1-f195.google.com with SMTP id w2so6257441qkf.2 for ; Thu, 10 Oct 2019 09:53:16 -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=PxQrbKz7G/kzZPsqDCuYAgClKxKHuF5bkewDB/MNXQ0=; b=dRg8tENLLSJOb/0gPPrVOY3cIF6uEFyc7CdJt+ktKCUtbtNV4hcVoM1ot40bcMdYQF okhrMOy6VC2Ie/teSGD+GtBb+xN51bjCVm0IItSdvcQmwFO1VDckjEZvAr7gpjmyxqQZ mV2kl7Ati31DiddAkg13HuPMrM6E2Mb3HbDAUo94/SeXZNkFsKLHJgLFA/e1ks6uEG1n b74sktrAYqE8dXSy0v3tT1eTajih67NT3dYMSiPVkrEF89Rl+PGfDiFuWisoGV+WyUOD t/xXmMPj11BWzi3+dDk40HDfVJPHLbkEv2RkaM5wf7XAg5Ytd2nBHMAOrCfSAt6c6Gkp 4mtg== 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=PxQrbKz7G/kzZPsqDCuYAgClKxKHuF5bkewDB/MNXQ0=; b=gX9duC8fE6LxkZkYTMtqnmBshc/kGibMsmAZ/re3I+uB+1dFtV1FN/7PgB5CTXdHSw qj18zb20AmyjsZEZXveq9QdCU73/zBHya3Smkj2xDZojCPvc9kgzMhkDzvMXkZDKKD/J +YyxyRPk8M0Oat2p/XzpP08eijDZgjIwtaoMJ05QbCMOIaW68nyIGhrSbGU+T3pDab78 ZtUCwwkGjkw0s5GdDpXqR/3WT6qFjjkxB7sk/tJPgwXxHtu7Gm9fBNyF41y0s9IJveLP 6Eh4IS7CycSBhNKiO4JuSVU3LilhtWCiymgZFLDjgOqegye6Oaulf2/q3i7rkyVJsTx/ dppQ== X-Gm-Message-State: APjAAAXFmY17eXxTFaHvWvHMpbCzqmbKgfZNdcycuEA3u1oZvms4DHjg QS/H718os2Xn3nvwkD5sSNk5JQ== X-Google-Smtp-Source: APXvYqx+MuvJq9zI+qzgj2LL+MvZe6fYJiPTxgM4qhY1FzwhsTuihLwOPnM7A6Cz6rR0ZK9+alwBpA== X-Received: by 2002:a05:620a:74f:: with SMTP id i15mr11103960qki.265.1570726396353; Thu, 10 Oct 2019 09:53:16 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::18ce]) by smtp.gmail.com with ESMTPSA id r7sm2894943qkf.124.2019.10.10.09.53.15 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 10 Oct 2019 09:53:15 -0700 (PDT) Date: Thu, 10 Oct 2019 12:53:14 -0400 From: Josef Bacik To: Dennis Zhou Cc: David Sterba , Chris Mason , Josef Bacik , Omar Sandoval , kernel-team@fb.com, linux-btrfs@vger.kernel.org Subject: Re: [PATCH 14/19] btrfs: only keep track of data extents for async discard Message-ID: <20191010165313.mzryz7rv6chijonz@macbook-pro-91.dhcp.thefacebook.com> References: <679c631d04f50a54f011c6317b99d96798a3ca4d.1570479299.git.dennis@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <679c631d04f50a54f011c6317b99d96798a3ca4d.1570479299.git.dennis@kernel.org> User-Agent: NeoMutt/20180716 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Mon, Oct 07, 2019 at 04:17:45PM -0400, Dennis Zhou wrote: > As mentioned earlier, discarding data can be done either by issuing an > explicit discard or implicitly by reusing the LBA. Metadata chunks see > much more frequent reuse due to well it being metadata. So instead of > explicitly discarding metadata blocks, just leave them be and let the > latter implicit discarding be done for them. > > Signed-off-by: Dennis Zhou Reviewed-by: Josef Bacik Thanks, Josef