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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52897C76188 for ; Fri, 19 Jul 2019 04:00:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2CD15218A6 for ; Fri, 19 Jul 2019 04:00:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563508819; bh=NGAEa7nxCla6yeOxFjos63IrCBcidctWmzU3WpluPhM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rnZ6IH3B3Xp+GOTSgo1ArhHRQ7X2H+1XwdlL0bL0xQCmmbrbfaEwGvw2Dq6y7/nJF CeOnqKEJptg4M864OX21VKKj9DjNqpZEL8+MNa25QsIPjGUwA3oYUzcO8gmb+ERI3Q hIw+XxySrAzPMlyWwAa6TX7Gw8bOK5p0MOd3QzKc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728034AbfGSEAR (ORCPT ); Fri, 19 Jul 2019 00:00:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:60022 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727243AbfGSEAJ (ORCPT ); Fri, 19 Jul 2019 00:00:09 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 65DD821852; Fri, 19 Jul 2019 04:00:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563508809; bh=NGAEa7nxCla6yeOxFjos63IrCBcidctWmzU3WpluPhM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wXKrDihp/S1cVan7L4zfjmAgAIzXlz6fMWnxvGRTLBM8R1Dk3lWkTAvYLkcXDUbvS llI5C0scOH1cTUGYr8VC+JvcJHNLtbVmDeq/2JOUHnx/UwhuPELJgHtDPXdKpzRPpa 9cFOvOfWe+SrDKyVuEwpMHFmr7ukTzxcgb2ssKjs= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ira Weiny , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Michal Hocko , Dan Williams , John Hubbard , Jason Gunthorpe , Sasha Levin , linux-mm@kvack.org Subject: [PATCH AUTOSEL 5.2 102/171] mm/swap: fix release_pages() when releasing devmap pages Date: Thu, 18 Jul 2019 23:55:33 -0400 Message-Id: <20190719035643.14300-102-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190719035643.14300-1-sashal@kernel.org> References: <20190719035643.14300-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ira Weiny [ Upstream commit c5d6c45e90c49150670346967971e14576afd7f1 ] release_pages() is an optimized version of a loop around put_page(). Unfortunately for devmap pages the logic is not entirely correct in release_pages(). This is because device pages can be more than type MEMORY_DEVICE_PUBLIC. There are in fact 4 types, private, public, FS DAX, and PCI P2PDMA. Some of these have specific needs to "put" the page while others do not. This logic to handle any special needs is contained in put_devmap_managed_page(). Therefore all devmap pages should be processed by this function where we can contain the correct logic for a page put. Handle all device type pages within release_pages() by calling put_devmap_managed_page() on all devmap pages. If put_devmap_managed_page() returns true the page has been put and we continue with the next page. A false return of put_devmap_managed_page() means the page did not require special processing and should fall to "normal" processing. This was found via code inspection while determining if release_pages() and the new put_user_pages() could be interchangeable.[1] [1] https://lkml.kernel.org/r/20190523172852.GA27175@iweiny-DESK2.sc.intel.com Link: https://lkml.kernel.org/r/20190605214922.17684-1-ira.weiny@intel.com Cc: Jérôme Glisse Cc: Michal Hocko Reviewed-by: Dan Williams Reviewed-by: John Hubbard Signed-off-by: Ira Weiny Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- mm/swap.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/mm/swap.c b/mm/swap.c index 7ede3eddc12a..607c48229a1d 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -740,15 +740,20 @@ void release_pages(struct page **pages, int nr) if (is_huge_zero_page(page)) continue; - /* Device public page can not be huge page */ - if (is_device_public_page(page)) { + if (is_zone_device_page(page)) { if (locked_pgdat) { spin_unlock_irqrestore(&locked_pgdat->lru_lock, flags); locked_pgdat = NULL; } - put_devmap_managed_page(page); - continue; + /* + * ZONE_DEVICE pages that return 'false' from + * put_devmap_managed_page() do not require special + * processing, and instead, expect a call to + * put_page_testzero(). + */ + if (put_devmap_managed_page(page)) + continue; } page = compound_head(page); -- 2.20.1