From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 967A31361 for ; Thu, 12 Jun 2025 05:23:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749705799; cv=none; b=LCYpwZ8c1BWEMAkLxfHm4KpQ6vDPtskLZae8mB9c+wzWRbZA+Gc6zoCB9usqLr5M5Qj5e7sf+93YitxwVJovkvmJkbK4k7a0DjN8GkcrCuA79GagMYF36+3My0Yr7A5Em7ITyXS18zExMOm8jfGwrG2rVrfkcwsyAHUR3dhAPHs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749705799; c=relaxed/simple; bh=VI7f9i+bnhXKxDTiWRv0kZeAbOygUdbkEghq1+O2yp4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZyCdGEUz70oN9U3QFws77K6JJZM/m6mj/nsz4srp2GvggqDhO40KI3hNVTFEiXB6FvDhgh69SCq8/EAXO66aqxbKjujEZ1pIgEP8xE5jVWujXqjtW7PTMfYzIUwndghYoXAG8o1YPYudhnoUGR0kMMSolKFGTiJYUb+qVi9hQDw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=pw1kEJLy; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="pw1kEJLy" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=VpkAbcQCnZQYXhX/zEAKUvWxviO7otMsczakR+S5DqQ=; b=pw1kEJLy8x1PAqZTXrNIwfYuOJ 7ZfdtDkYqSBBtxyl63ZyjQfK3xTuk0KHCPX8Y3PiCmdswI7rYKRcyq/qMzta8EHg9XxKelA92+/oq 6Y1JE7Af8oAjR066tyEGRXahZkHw4iWCDoj0kKBRhoHCq0kSgR3FEzKilYMAybf1etHXOP6pNmFIv c2rNSnxS/SPljCnxR68mwHL7YgXcVy7Jetw7MYWCxo5L8TxVMJR+HCIK3sAedgSVa7WLyyCTQaYH4 s8fVvGoCOPQEr0WMvuO+bsuj9aizknLcTKLZOrh3WNhRO4miJTQmE8g+FtbzumoK1h4iOWn59GvDZ evqvtc8w==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uPaPG-0000000CDqd-16LZ; Thu, 12 Jun 2025 05:23:18 +0000 Date: Wed, 11 Jun 2025 22:23:18 -0700 From: Christoph Hellwig To: Jens Axboe Cc: "Mohamed Abuelfotoh, Hazem" , "linux-block@vger.kernel.org" Subject: Re: [PATCH] block: use plug request list tail for one-shot backmerge attempt Message-ID: References: <4856d1fc-543d-4622-9872-6ca66e8e7352@kernel.dk> <82020a7f-adbc-4b3e-8edd-99aba5172510@amazon.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, Jun 11, 2025 at 10:22:43PM -0700, Christoph Hellwig wrote: > Maybe byte the bullet and just make the request lists doubly linked? > Unlike the bio memory usage for request should not be quite as > critical. Right now in my config the las cacheline in struct request > only has a single 8 byte field anyway, so in practive we won't even > bloat it. Oh, and we actualy union rq_next with a list_head anyway..