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 08BDCC38145 for ; Tue, 6 Sep 2022 06:48:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6BA4E80254; Tue, 6 Sep 2022 02:48:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6437380224; Tue, 6 Sep 2022 02:48:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4E38D80254; Tue, 6 Sep 2022 02:48:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 3C9B480224 for ; Tue, 6 Sep 2022 02:48:04 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id E8378141429 for ; Tue, 6 Sep 2022 06:48:03 +0000 (UTC) X-FDA: 79880730846.08.DC0E2E2 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf27.hostedemail.com (Postfix) with ESMTP id 8670E400A9 for ; Tue, 6 Sep 2022 06:48:03 +0000 (UTC) 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=oFuTZk4zKE5mAVI0W5HcV1QEwth0M1OUe/8JfOFc7i4=; b=qu2isCifsZ2DAo2Q5ZJ8unnHj8 lYJqoyJRc11lTwpPaUNVLA+1+Y87Tvpx76OepMVZu+0gIu/+vIuNEeff37Z4KS8KT//T7tAbGaLko XyDJaWYJhzxKG8CK4N4THMRd/2w88PEn3nJp0mia12EUesXoFRN4lHfipW1PMHBt6cJA88nJzgmQv XpF7iA46K9x9Mp0blxVRAOYNNICAbtjNtF+rYr+zfhmIpxZDK4CKNHRp6VKJpXp5gwGZFE0pc2KY9 WGnsJmMDwaaAi+FpCAyEsH5JCqI8U2PJBGjMc4jwhsPw+cHPHYzJolat+Lpf3slGwBhEmDxRmrJ58 M9K8XWLQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVSND-00AXVf-Qh; Tue, 06 Sep 2022 06:47:51 +0000 Date: Mon, 5 Sep 2022 23:47:51 -0700 From: Christoph Hellwig To: John Hubbard Cc: Andrew Morton , Jens Axboe , Alexander Viro , Miklos Szeredi , Christoph Hellwig , "Darrick J . Wong" , Trond Myklebust , Anna Schumaker , Jan Kara , David Hildenbrand , 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 v2 4/7] iov_iter: new iov_iter_pin_pages*() routines Message-ID: References: <20220831041843.973026-1-jhubbard@nvidia.com> <20220831041843.973026-5-jhubbard@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220831041843.973026-5-jhubbard@nvidia.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=qu2isCif; spf=none (imf27.hostedemail.com: domain of BATV+3c9dadc9e27e1b9c7a6f+6953+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+3c9dadc9e27e1b9c7a6f+6953+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662446883; a=rsa-sha256; cv=none; b=kjGiKjBS0SfVI3DzoHyfcL95fZ8hsyauOZACK7+1PodS3pEeC4mNTLEnFubxGOY4C85wch uzJxdcHDnqZTe9pn44pUmoJPBsbhIIJul6scSh5N+Osxo3gYPJTy3P1TUmcQnLxy6KldjJ nSXJl8xdtgIu7/xsrJS0kpTSrxMqe9E= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662446883; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=oFuTZk4zKE5mAVI0W5HcV1QEwth0M1OUe/8JfOFc7i4=; b=ssk8HkU0AlZ1xk703Zkc82Gwt7nr8vM4fO/nxeVANmjJiKF/kBmMaQHfytl+edk7wa3zcM nwyatk8gRba37Iz7NsyGQFyG2J3QR2BFBiaydO64xEYmoB2pVgVcRSifFvvhjdmvefCmGL +cLC6RPKPLp3/5lq7pX/9UKZzVn/Ry0= X-Rspamd-Server: rspam02 X-Rspam-User: Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=qu2isCif; spf=none (imf27.hostedemail.com: domain of BATV+3c9dadc9e27e1b9c7a6f+6953+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+3c9dadc9e27e1b9c7a6f+6953+infradead.org+hch@bombadil.srs.infradead.org; dmarc=none X-Stat-Signature: xikdsjihiheatbmddcbe7crruuregc55 X-Rspamd-Queue-Id: 8670E400A9 X-HE-Tag: 1662446883-847349 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: I'd it one step back. For BVECS we never need a get or pin. The block layer already does this, an the other callers should as well. For KVEC the same is true. For PIPE and xarray as you pointed out we can probably just do the pin, it is not like these are performance paths. So, I'd suggest to: - factor out the user backed and bvec cases from __iov_iter_get_pages_alloc into helper just to keep __iov_iter_get_pages_alloc readable. - for the pin case don't use the existing bvec helper at all, but copy the logic for the block layer for not pinning.