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 6BFA8C433EF for ; Thu, 10 Feb 2022 19:17:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A688B6B0071; Thu, 10 Feb 2022 14:17:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A16BE6B0075; Thu, 10 Feb 2022 14:17:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8DDE86B0078; Thu, 10 Feb 2022 14:17:31 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id 7A3576B0071 for ; Thu, 10 Feb 2022 14:17:31 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 465D8159A for ; Thu, 10 Feb 2022 19:17:31 +0000 (UTC) X-FDA: 79127829102.03.128C48B Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) by imf14.hostedemail.com (Postfix) with ESMTP id CA97D10000A for ; Thu, 10 Feb 2022 19:17:30 +0000 (UTC) Received: by mail-pl1-f182.google.com with SMTP id x3so2697474pll.3 for ; Thu, 10 Feb 2022 11:17:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:mime-version :content-disposition; bh=VFvt2qkldnELMoC2bjs+OiTFLeMglGyEe/KOlRSrFPg=; b=Mt+K4f4Z5tTvcvLCiB7B1+ELRU1eV8ITrrGZIjrOIuaHkLs9oAE2PvsxEdY/HiZOdn rPkQYqw52SdvrFY7RF6M+QPzZzdkwrr7tyecxQDCZAjUX3fQFIDcNWYuKCXMTvtK4pJ0 hbS3xwEIEaR13b1DQ2jk4a6roKxL88umON9aLTQULqq6sG1zM8hu/BCbDBWttAsX0oB7 OEQK7mw0Pry/3NRpBakM8GG3on4ec1U3rpDcsudsZQz2JrXUyK0Eus9lV6st1CZDzv9R xz4nGiG5vAy8IeMkMyxd+9xe4kg/D86EtsbOsLiWF1jDVczztwOkcEznvGhjkH/oyqm4 tgyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :mime-version:content-disposition; bh=VFvt2qkldnELMoC2bjs+OiTFLeMglGyEe/KOlRSrFPg=; b=n5imr8eQZeVH+kX+znJFbUPgXLaq7s+xEQLZfnMG9amg5UA9MJpk8RzgLdcDDlqdwu xGxOIpT5TQhlLQ8JyGez0NrzH0lenVAPC28qH04R45uT8qaX6bj/8P6vHzmlih34EBzp Qz/di6U2foH3Cxryk4k1+CsA44ZBsSm78HyaSx7GmQTxpY2iEjAyIEds81/WCfh6JkYT oyKlsNjGgeZnqQxeYEXuYU3YMY+Bzx7DS+Ofi73UToOkLLdUbjNo3duWqj26FkJ6CvG7 g4yUONt4UlyaeD1dIuzWKwo5UcFKKOhq3PmtjMonMeTZHXUcFVL+4Dpe3mpRBVDH1Oha zaBQ== X-Gm-Message-State: AOAM531MB2TZmA8XLCXwbHNCO+jHMsNelv+v8xtX70iZyRaSvP3K9BCZ looqS+lPJR+ebIsY8fzv/24= X-Google-Smtp-Source: ABdhPJxudCrdOavU2G4udreBtQwdp50xSkFsvlI1XpG+5jHk3B1Xc+OUuY+Q761FtI4njg9rfpvB5A== X-Received: by 2002:a17:90b:2251:: with SMTP id hk17mr4345884pjb.210.1644520649489; Thu, 10 Feb 2022 11:17:29 -0800 (PST) Received: from google.com ([2620:15c:211:201:4c8c:3496:9911:5b66]) by smtp.gmail.com with ESMTPSA id t9sm2891556pjg.44.2022.02.10.11.17.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Feb 2022 11:17:28 -0800 (PST) Date: Thu, 10 Feb 2022 11:17:27 -0800 From: Minchan Kim To: John Hubbard Cc: linux-mm , LKML Subject: pin_user_pages supports NULL pages arguments? Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Queue-Id: CA97D10000A Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=Mt+K4f4Z; spf=pass (imf14.hostedemail.com: domain of minchan.kim@gmail.com designates 209.85.214.182 as permitted sender) smtp.mailfrom=minchan.kim@gmail.com; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=kernel.org (policy=none) X-Stat-Signature: ztx4njhcs1389a9yikmrrz6jj7k33pri X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1644520650-468566 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000027, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: * pin_user_pages() - pin user pages in memory for use by other devices < snip > * @pages: array that receives pointers to the pages pinned. * Should be at least nr_pages long. Or NULL, if caller * only intends to ensure the pages are faulted in. pin_user_pages(,, pages = NULL, ); gup_flags |= FOLL_PIN __get_user_pages_locked __get_user_pages .. VM_BUG_ON(!!pages != !!(gup_flags & (FOLL_GET | FOLL_PIN)));