From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E93F746AA9C for ; Tue, 6 Oct 2026 14:00:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791295236; cv=none; b=YVc5vpSVrrJYFMVMorEursyQ11YqYyItbpbk/GV8CE65tBvw0eCWTOcGNnC3lrm4h1lagiLzsI0EUEjcNlwyxsxzjrHZYcA18d0FgFrkeKP7o8c+BNDwXxy5fZ0Zg8T/n93D+PhrSuOMdEPR3CPGcCtXdVg0skoXd7Grc00VrSI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791295236; c=relaxed/simple; bh=IvxQxF3UXEvW4AulGQz4dRRqGz31/slpuZJK3rSrPOw=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=Enyy6Dx0aqS1ae0yqfS+DdKpvu6tKhxXkiv+o/CUdvJLZTJfl5r4Yx43pVInAOHYtr2UXpH/jEKAJuoihWbSiLPZyii+l2DUG1z0Euwnj3Ux0bfsHHYX4Q9a7/EoGCRFrAEYkwvYymzwkPw2qMEYuYAhAh/AuiBx2IYygqygm3Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jjD7Kzun; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jjD7Kzun" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2279C1F000FF; Tue, 6 Oct 2026 14:00:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791295234; bh=AXezEU08QBeG6wMOvFEJXbVaFlnnw6bnJlBhBZAQsbw=; h=Date:From:To:Cc:In-Reply-To:References:Subject; b=jjD7KzunqpKEnta0ZDKOOYBRfKpSXs9xgCQ43x9kD0fLobkRTF5QkDvkEsTHTg0Wj RdB5CgL174waoHsZ3F6hmM/WDKgoK1Zm4loa6iAdOLTZCIqCKrt+lHANrYr6BYhy/9 sCeo/AjY23JriAa5g6Pjp3P4X+S+pFMYzvigWgytSvXHoAsviR4vT8Nwnwq6oz49Eg 9zjF7DuMbEOsOp6GXI6Vcex3tHBbWw/zxBWsG/eLHxCW08V1g8jb95cjlM06ZNfhmj wS/fbxi9uR4U1k4sPfl+YasgGXiDLcKp4BZe781RwIjQJ0WyzGGTWmdKFQ42x4DORB lvNteIN4cxGEg== Received: from phl-compute-10.internal (phl-compute-10.internal [10.202.2.50]) by mailfauth.phl.internal (Postfix) with ESMTP id 62F09F40066; Tue, 6 Oct 2026 10:00:33 -0400 (EDT) Received: from phl-imap-15 ([10.202.2.104]) by phl-compute-10.internal (MEProxy); Tue, 06 Oct 2026 10:00:33 -0400 X-ME-Sender: X-ME-Proxy-Cause: dmFkZTFbe4bmLonpBE+N+mIT1TkF00SkHA/tjY++bZCa3yZi0I08WccuIFyxCY7OTcT2xN 4rAYsbaJwnCMgDxJYrjW6MFuBBmkjc4ACyy7ZcsnS1K//Vl+uyyFKDw/A2ZWChPECk8N18 hSgnDT42q80/yA/msTTYf0ZrXMGvynIjwdTpent/xU/WspQqvym1UqYKtcXwAkooFFLg5W ZLCqDJBpXQvWEmVq9RIn90mylRb768ARphhXU7aLiU6+3HVoYew280LGC+VOJceOtlZd1+ gH2e1uTKFAsDv92SgwbXX4vFD5A7gL9zJXYKhRP0OjIHKzEuQhNNBQW4p1wjSQP1dFKPEV gfuV16KHGVbb+Rhx77x62q4Y84rVPguaVZs3qgdFenUp1zQnj70e6GztQC+IUPkEmBYZY/ AUqHKP7AueCaxcUlLyu6UMB1Sar5xSDUN/xdAEiMDP0UJ9HloqNPjMobwHTI3x9TIRyVVa 2zeZOQmA0E6kKumPkJpgKqYJI+LlcyXTGOctPOmFO3WoFsGUSHIEkRzyd6CTSE1Jh8BJMC LFlZ6n3FaGiIp+qMavZrC17EsBN4kGzcuUfZ6xRawGcmBF8NdUSBpVQZ43wY2QGW5ymiZQ GNyxwI0gw/uzcY/ub+nqka7ZlWZ8AOFcUrfnEOmhKR5dWDh5TvTvWdgCUBlQ X-ME-Proxy: Feedback-ID: ifa6e4810:Fastmail Received: by mailuser.phl.internal (Postfix, from userid 501) id 45380780070; Tue, 6 Oct 2026 10:00:33 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ThreadId: AgBbH0lsTNlc Date: Tue, 06 Oct 2026 10:00:13 -0400 From: "Chuck Lever" To: "J Louis Kaplan" , dai.ngo@oracle.com, jlayton@kernel.org, neil@brown.name, okorniev@redhat.com, tom@talpey.com Cc: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org, anna@kernel.org, jgg@ziepe.ca, leon@kernel.org, trondmy@kernel.org Message-Id: In-Reply-To: <20261006090028.3412544-7-Louis.Kaplan@arm.com> References: <20261006090028.3412544-1-Louis.Kaplan@arm.com> <20261006090028.3412544-7-Louis.Kaplan@arm.com> Subject: Re: [RFC PATCH 6/6] sunrpc: Allocate svc request pages from large folios Content-Type: text/plain Content-Transfer-Encoding: 7bit On Tue, Oct 6, 2026, at 5:00 AM, J Louis Kaplan wrote: > Bulk allocation of base pages does not guarantee physical > contiguity, limiting opportunities to coalesce service buffers. > > Allocate large folios opportunistically and populate the service > page arrays with their constituent pages. Cap folio size at > 64 KiB and allocation order at PAGE_ALLOC_COSTLY_ORDER, falling > back through smaller orders to bulk base-page allocation. > > Retain one reference per populated page-array slot so existing > page-based ownership and release paths remain valid. > > Signed-off-by: J Louis Kaplan > Assisted-by: LLM Given past experience with contention in the page free path, IMO this one needs careful macro and micro benchmarking. I wonder if this change should get merged first instead of last. It's probably going to have broad impact and high risk, and will need testing across all hardware platforms and on large- and small- memory configurations. -- Chuck Lever (Come to NFS bake-a-thon! https://nfsv4bat.org)