From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 013.lax.mailroute.net (013.lax.mailroute.net [199.89.1.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 44019148850 for ; Tue, 10 Feb 2026 18:31:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770748295; cv=none; b=k79m9WcfjAnfM6FzR1/5GOE0u1+cAdzwp8bVTipeLtmQHsqeDvZu9YWBOR6jyXZPG80vl7x5P2KluL16VxRzfEA50JRWXTe+PfeikTsXP4MO8Vn/0NgL8EPQI8gf8xQNESIJSjGhCxmVO22Hz1hsgF9o6S/703Ffqr4k+OKnRm8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770748295; c=relaxed/simple; bh=6AzQS43yTBJ5NGqjOLytz71SzECT8CJ6Powv6a4cwNg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Xe9pNRMy09yf47aCv+p+c9PaZHMsvmuakjR2bd1uX+kUBehSl3Qom2Bvxdn3WMdXsEYXw+vye+sjEKWkSQat4C609mL2A36SiK7b+EvafCN+S6yNYGxj3FLJ/AwJV3/QDOTdbZ7aCGAmijswK9H2rP63g1xS9WFXidwb3N1o1L8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=INgNoVPW; arc=none smtp.client-ip=199.89.1.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="INgNoVPW" Received: from localhost (localhost [127.0.0.1]) by 013.lax.mailroute.net (Postfix) with ESMTP id 4f9VWg3ZJBzlh2ry; Tue, 10 Feb 2026 18:31:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject :user-agent:mime-version:date:date:message-id:received:received; s=mr01; t=1770748286; x=1773340287; bh=6AzQS43yTBJ5NGqjOLytz71S zECT8CJ6Powv6a4cwNg=; b=INgNoVPWTghdISvgFYQCgx/fFQXsj/KpV2bUMOzc 6b4Y8Vv0yZ2PSaqzArqBc/EAv6TOqA/RENWfBXU8wcv2pjB2SUjUyp/8EPrgEzWr 2rlsfJONbjc9vEYrN+XJhTH/EYqTfpWddUe7Z2XUw5kMuEQhrt4pUq8zWHMlLB2A YfUwBQr1IL9StIQNNnW93Imyb2bi7htQc/gg6+wsIBXTXde49DHskQ7uxe+6N75q BbyMsMDkiqt+jKoHCF8tkncy3J4LJGe5z3r57njJV9zazsPAWQZOm+tcq8trROqg SFbcCWSY5AhESsaxFdpYRRBw/6mrumuFVZWF2CxzgCdb3w== X-Virus-Scanned: by MailRoute Received: from 013.lax.mailroute.net ([127.0.0.1]) by localhost (013.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id Espza_s5LMsj; Tue, 10 Feb 2026 18:31:26 +0000 (UTC) Received: from [100.119.48.131] (unknown [104.135.180.219]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 013.lax.mailroute.net (Postfix) with ESMTPSA id 4f9VWd1knhzlh1Rs; Tue, 10 Feb 2026 18:31:24 +0000 (UTC) Message-ID: <07f7ee7b-06fc-4fb7-a826-d465562ced24@acm.org> Date: Tue, 10 Feb 2026 10:31:24 -0800 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [LSF/MM/BPF TOPIC] A block level, active-active replication solution To: Haris Iqbal Cc: lsf-pc@lists.linux-foundation.org, linux-block@vger.kernel.org, Jia Li References: <0ea1530f-31d0-43b6-b35b-1286fc58fd19@acm.org> Content-Language: en-US From: Bart Van Assche In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/10/26 5:06 AM, Haris Iqbal wrote: > We did some quick runs to get the sync time and performance numbers > during syncing. Hi Haris, Thanks for having shared this data. Instead of performance numbers I'd like to see more information about the implemented algorithm. The description at the start of this e-mail thread says "The proposed solution tracks dirty IOs through a dirty map". How does the dirty map work? Is there a single bit in that map that tracks whether any of N logical blocks has been modified? If so, is the worst case behavior that logical blocks 0, N, 2*N, ... are modified and no other logical blocks are modified? Does this mean that the worst case behavior involves resynchronizing N*M logical blocks if only M logical blocks have been modified? Thanks, Bart.