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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35563ECAAD1 for ; Sun, 28 Aug 2022 00:12:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6AFB16B0073; Sat, 27 Aug 2022 20:12:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 65FAE6B0074; Sat, 27 Aug 2022 20:12:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 526CC940007; Sat, 27 Aug 2022 20:12:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 40C866B0073 for ; Sat, 27 Aug 2022 20:12:24 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id B023FAB252 for ; Sun, 28 Aug 2022 00:12:23 +0000 (UTC) X-FDA: 79847074566.13.F4353BA Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf28.hostedemail.com (Postfix) with ESMTP id 57C99C0023 for ; Sun, 28 Aug 2022 00:12:23 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2458460F00; Sun, 28 Aug 2022 00:12:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8E9FC433C1; Sun, 28 Aug 2022 00:12:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1661645541; bh=pKUoaQ9EcjJggSkeqY7Olvpsm3d5dLwR/wl/BB+U5g8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=TMpAOVjbK9E3fz0ooSfvWL268lrlX3TxQoLp4an1G52borowaZOgsBN4HTAMzlSZh n/go2Bd+b/Q7boVjtKX7sXTsnaPBkr/ToNRad4gXMu3cYY9wSWwQXUZhWqQKOjm5Zr f0vMAg/QZlaEUyt8kktBXmYn5/Sp4RnqSXTXzcwA= Date: Sat, 27 Aug 2022 17:12:20 -0700 From: Andrew Morton To: John Hubbard Cc: Jens Axboe , Alexander Viro , Miklos Szeredi , Christoph Hellwig , "Darrick J . Wong" , Trond Myklebust , Anna Schumaker , Jan Kara , Logan Gunthorpe , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, LKML Subject: Re: [PATCH 2/6] block: add dio_w_*() wrappers for pin, unpin user pages Message-Id: <20220827171220.fa2f21f6b22c6d3047857381@linux-foundation.org> In-Reply-To: <4c6903d4-0612-5097-0005-4a9420890826@nvidia.com> References: <20220827083607.2345453-1-jhubbard@nvidia.com> <20220827083607.2345453-3-jhubbard@nvidia.com> <20220827152745.3dcd05e98b3a4383af650a72@linux-foundation.org> <4c6903d4-0612-5097-0005-4a9420890826@nvidia.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661645543; a=rsa-sha256; cv=none; b=XlLD9BBrW9Hkri/7Fa2NXN0qdIT8xAM4dWBDNXzfmUmCp0/PsCKvpAyh90eGUZMXnGXalU Cm0jlcJC4FPZQtCJlDnr0HE6NYO0ib9FyWRE4d7w99vOIDQyO9hPJcVxOexLVD/AyYuI1q YyDCBTkdjwRI8AbIAOYidSaaXapFOs4= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=TMpAOVjb; spf=pass (imf28.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661645543; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Bpb+O5xBVwlyF4LW0dhUD8HaKYLuY4sKDEQDcybQZqg=; b=wd7lX140PDR8msAEb0sO/TggLtbxCyK5P/YYbZsMMrBKnakekIqhWziLtVWOhZChBZcw1a Wf9lzm5PLoIJV9jVLYKu5FHLyjv9VNW1AQDtlzy5vN6demj0WqiyEfHMw/OrW+aGvSbojV Fb4Gi3iDIgGX80WMhWlRsKatAuXgFno= X-Stat-Signature: 4wx9k1upk76dzxi4kjtmjjw5364gpkjk X-Rspamd-Queue-Id: 57C99C0023 X-Rspam-User: X-Rspamd-Server: rspam06 Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=TMpAOVjb; spf=pass (imf28.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-HE-Tag: 1661645543-970849 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, 27 Aug 2022 16:59:32 -0700 John Hubbard wrote: > Anyway, I'll change my patch locally for now, to this: > > static inline void dio_w_unpin_user_pages(struct page **pages, > unsigned long npages) > { > /* Careful, release_pages() uses a smaller integer type for npages: */ > if (WARN_ON_ONCE(npages > (unsigned long)INT_MAX)) > return; > > release_pages(pages, (int)npages); > } Well, it might be slower. release_pages() has a ton of fluff. As mentioned, the above might be faster if the pages tend to have page_count()==1??