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=-9.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 DA1D0C07E99 for ; Tue, 6 Jul 2021 03:11:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C1EB161986 for ; Tue, 6 Jul 2021 03:11:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229919AbhGFDON (ORCPT ); Mon, 5 Jul 2021 23:14:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229827AbhGFDOM (ORCPT ); Mon, 5 Jul 2021 23:14:12 -0400 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04767C061574 for ; Mon, 5 Jul 2021 20:11:35 -0700 (PDT) Received: by mail-pf1-x42c.google.com with SMTP id 21so18253878pfp.3 for ; Mon, 05 Jul 2021 20:11:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:cc:from:subject:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=KN5Dq3VA+/OK1czIe0yr+RPnDgcQ25YkL9hr4K2AuxQ=; b=FbVlosVGAhF2T6PbGoyZZARHDAwjMwIpt3FNw1ekVJ+XmMI1+ZamoDfeWjFUHawEfC 46/cNs0JkmNw3vvdf57w/nlsupI7oLAh42FvEz9zqK2+cVfkvxclUy1pWPjTG+jz0Al9 f8AJ0O3icq2SH1G4OYhIXPAd4gciEIQ3eU0sbeWqxmtd/njqb79EAXia0kyGseQkWBUn msgzF7zHuiTRT/CiGjJYK1dk7VJFV4YK/xI0hha5LAt2LcBIgc2vkfYepbTN+wsyunSo jDzBCM99o+GP2VQk1aL/flnMk2DNhSWQ/K32Gst94HfNPYBFqwCXZN+NwuyH8IxGR6nM hY7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:from:subject:message-id:date:user-agent :mime-version:content-language:content-transfer-encoding; bh=KN5Dq3VA+/OK1czIe0yr+RPnDgcQ25YkL9hr4K2AuxQ=; b=ZfOQDwuLFUvnSPpYW1snV/SFSJq4oNl8PfTe4q2PHjcNlAJ4fDH3U9MuNhoADEZ2aY 7+ag7+8kPBxZ6Ij5xYWJmsI5EFXyDti7TNzr4b+0HVJdhWrIowzmBmrfIXVR1BlFwy5u hbhxPuXpacJNnWQ61/pl/vX/3g9OIPHpTVWjS5noTuGQSYwZGmYsSNat8Y4HdDLC6hc3 qPujXOfhOTd2441mY6ooM9HSaYuh/hXNGmZCJe8lG+kqMMWh28taYLqmhUHKQxtMlaok sRzDZFiJCNpAUHyNIFYQ8RoQF/RoBsjfd6kFYgkUKq3AWf2au0g6QbYgEF8Io48jtexI zNjQ== X-Gm-Message-State: AOAM533gFN0fpB/D6JvjGi0goSNNYsvX5uV0nObgSyDdeC91r8bfPQii tyOApIdXOtrFKnD+9J159MVmPmHCEro= X-Google-Smtp-Source: ABdhPJxOx466+SDypIkdhWOH43VDZXHJ52iYosJzhttWfk3yW3ZZvGuxLxAeo/K0egb4q5DVSgr3Pg== X-Received: by 2002:a62:7a08:0:b029:323:c5f:6503 with SMTP id v8-20020a627a080000b02903230c5f6503mr1504362pfc.59.1625541094527; Mon, 05 Jul 2021 20:11:34 -0700 (PDT) Received: from jianchwadeMacBook-Pro.local ([154.86.159.246]) by smtp.gmail.com with ESMTPSA id b33sm3699584pgb.92.2021.07.05.20.11.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 05 Jul 2021 20:11:34 -0700 (PDT) To: martin.petersen@oracle.com Cc: jejb@linux.ibm.com, linux-scsi@vger.kernel.org From: Wang Jianchao Subject: Discard performance regression after "scsi: sd: Remove LBPRZ dependency for discards" Message-ID: <279cb008-4c92-0535-efdd-6e877bea7349@gmail.com> Date: Tue, 6 Jul 2021 11:11:25 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi Martin We have a sata ssd with following parameters, max_ws_blocks = 0 max_unmap_blocks = 262143 lbprz = 1 lbpu = 1 unmap_limit_for_ws = 0 But the discard performance is very different on 3.10 and 4.18 series, On 3.10 series, the bw of discard is ~60G/s, but on 4.18, it is only ~2.7G/s The reason is the discard_max_bytes, 3.10 series : 4294966784 4.18 series : 134217216 This difference happen after commit commit bcd069bb250acf6088b60d189ab3ec3ae8dd11a5 (scsi: sd: Remove LBPRZ dependency for discards) @@ -2842,7 +2829,7 @@ static void sd_read_block_limits(struct scsi_disk *sdkp) sd_config_discard(sdkp, SD_LBP_WS16); } else { /* LBP VPD page tells us what to use */ - if (sdkp->lbpu && sdkp->max_unmap_blocks && !sdkp->lbprz) + if (sdkp->lbpu && sdkp->max_unmap_blocks) sd_config_discard(sdkp, SD_LBP_UNMAP); else if (sdkp->lbpws) sd_config_discard(sdkp, SD_LBP_WS16); Before this commit, it enters SD_LBP_WS16 case, but after the patch, it enters SD_LBP_UNMAP. Which should be the correct case ? Thanks and Best regards Jianchao