From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.60 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794317381; b=dETyEFp0plnEv8yMI2HplEXbSPTGL3fza53Rk8Mnr4uBhdKvtCdStFDtI6YNn7Nf6D1q RARIAVyHvi9MZ5I8cEP5cBpmQGmop5mqvaFkBJpDyEI//f/CaWb+HftwgOG7XLUpMhQus nQbW1tz4T4PkpYO8h4yMK//odGEFcqmPNUrH7xy3pbF8BS7rgM4D3sI/Cv1gVYWiEan82 2Efpn6HIpaMRmjRNt19Z9TxCr96xeeTDELp7JQ2kN1KKXC27rEAcWmNrqVKMVAHRow+e0 h37ejhRwtHx3WbqFvsCFznsCP08yAuOxeJ9f2NhsOgTUqhzN2cu6iWMMO+2/enXGPUw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794317381; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:Subject:Date:Message-Id: MIME-Version:Content-Type:Content-Transfer-Encoding:X-B4-Tracking:To: Cc:X-Mailer; bh=me+Mok8uviVB0NYu7k/EZr8NLfEietX24VsByp8qjw8=; b=joZ1KvEH8z7U4B2atW/N2bkANU/7Hl+btGOCJUIl1TD32vLYipKfX5rH6eSkw6P2nQOK y37uFMQrG6WnuFaYe+INxHfATJBVpCJdPLghR4dRcg2jLQKP3kJ8bWYPr6lkL6MF/Zybi aBqlIyJta5tc9Sq5fCX0+w9XN0FPhQI+NgPZe18TcmotjV7UDnptBtV5vnxlJe+OI2hKC 33wqpU3t8sUg33UFnfI0rHnVf9r5JZX8BNN6+/j2GBlXmI9L3Oc22OhFUjs4i8wrZ4qWs Y50kg0bEoKA3Vnc8kfzpTYLOZOMjXr5oICp29FhDR8+PpbX+ikSKDf0Kec5xqpCYLIA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=WXfrJjJC; arc=none smtp.remote-ip=91.218.175.60 Received: from mta0.migadu.com (out-60.mta0.migadu.com [91.218.175.60]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C369F606A764 for ; Tue, 10 Nov 2026 13:29:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org C369F606A764 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=WXfrJjJC X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=TqP5vO691FPgdSXaJrVOyHuZq5HHrrDwziy9HECDC6I=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794317378; v=1; x=1794922178; b=WXfrJjJCbTwrC9fiPFsSbMJUC4Ao8udEQ6VunJsz9jrta4xsTU7mqyGlvAK7Jz4u26xSmMHh zMSL7aiqzt4HM8HG7qCT8ID8xw/76RTZJrcruyuWZW9Al0hpmgT+ylvfCt69ZRiy/DUFiWvcwLQ Uiwm8N9BpuSeaGTiGwQax+LA= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 52397fc075a5a131; Tue, 10 Nov 2026 13:29:38 +0000 X-Mizu-Trace-ID: 52397fc075a5a131 X-Migadu-Flow: FLOW_OUT From: Qiliang Yuan Subject: [PATCH 0/2] scsi: target: alua: Skip grace periods on LUN add and remove Date: Tue, 10 Nov 2026 08:29:32 -0500 Message-Id: <20261110-bug-target-alua-lun-gp-v1-0-127a46efdae9@linux.dev> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAD0c82oC/x3MQQqAIBBA0avErBtwQiK6SrSwmmxALDQjEO+et HyL/zNEDsIRxiZD4EeinL6C2gbWw3jLKFs1dKrriUjhkizeJli+0bhk0CWP9sJFk+J92Ii0hhp fgXd5//E0l/IB2rkvQ2gAAAA= To: "Martin K. Petersen" Cc: Mike Christie , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org, Qiliang Yuan X-Mailer: b4 0.13.0 Creating or removing a LUN through configfs attaches it to, or detaches it from, its ALUA target port group, and both helpers wait for an RCU grace period afterwards. Neither wait protects anything, yet each costs one grace period per LUN, which adds up to seconds when exporting or tearing down many LUNs, e.g. when targetcli restores a saved configuration. Drop the wait on attach (patch 1) and on detach (patch 2). Adding and removing 256 LUNs of an iSCSI TPG through configfs, five rounds alternating with and without the series, takes (median, min-max in parentheses): 256 LUNs before (ms) after (ms) change add 3144 (3104-3175) 1379 (1277-1393) -56% remove 5222 (5165-5244) 3551 (3436-3810) -32% Signed-off-by: Qiliang Yuan --- Qiliang Yuan (2): scsi: target: alua: Don't wait for a grace period when attaching a LUN scsi: target: alua: Drop the grace period wait from LUN detach drivers/target/target_core_alua.c | 2 -- 1 file changed, 2 deletions(-) --- base-commit: b3dfbde62cf1981c4638939c159dfd087b7a72e9 change-id: 20261110-bug-target-alua-lun-gp-b410ef8d1144 Best regards, -- Qiliang Yuan