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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 63AD6C43331 for ; Thu, 2 Apr 2020 04:05:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 263AF20747 for ; Thu, 2 Apr 2020 04:05:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="fPU1zuva" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 263AF20747 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CA61A8E0031; Thu, 2 Apr 2020 00:05:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C7CB88E000D; Thu, 2 Apr 2020 00:05:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B93308E0031; Thu, 2 Apr 2020 00:05:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0009.hostedemail.com [216.40.44.9]) by kanga.kvack.org (Postfix) with ESMTP id A02428E000D for ; Thu, 2 Apr 2020 00:05:55 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 62E63181AC9CC for ; Thu, 2 Apr 2020 04:05:55 +0000 (UTC) X-FDA: 76661576670.02.toys14_33aaa5f266c3b X-HE-Tag: toys14_33aaa5f266c3b X-Filterd-Recvd-Size: 5277 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Thu, 2 Apr 2020 04:05:54 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 61C262078B; Thu, 2 Apr 2020 04:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585800354; bh=bbgNPvPOjN8HYHS/m2qSCEZX4AaDrVoGCNmOXKr4/0s=; h=Date:From:To:Subject:In-Reply-To:From; b=fPU1zuvaxaD39MwML3NNKj5XJEpVRlwInTmcWiFatRvcth/wlXCZoueGQRzyyonpv 2XJQz0yQdoNYdqAkfJAdxnGw6coo5oxRAbeRrQ33fS9lHICnGUBfDjYjPRUoeUoxtp CkUFO7sOgfe7kA/sCWdGpC0BNW6T3WYEecvrPqZE= Date: Wed, 01 Apr 2020 21:05:52 -0700 From: Andrew Morton To: akpm@linux-foundation.org, corbet@lwn.net, dan.j.williams@intel.com, david@fromorbit.com, hch@infradead.org, ira.weiny@intel.com, jack@suse.cz, jgg@ziepe.ca, jglisse@redhat.com, jhubbard@nvidia.com, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, mhocko@suse.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, shuah@kernel.org, torvalds@linux-foundation.org, vbabka@suse.cz, viro@zeniv.linux.org.uk, willy@infradead.org Subject: [patch 049/155] mm: dump_page(): additional diagnostics for huge pinned pages Message-ID: <20200402040552.NUvzaqWOm%akpm@linux-foundation.org> In-Reply-To: <20200401210155.09e3b9742e1c6e732f5a7250@linux-foundation.org> User-Agent: s-nail v14.8.16 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable 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: =46rom: John Hubbard Subject: mm: dump_page(): additional diagnostics for huge pinned pages As part of pin_user_pages() and related API calls, pages are "dma-pinned". For the case of compound pages of order > 1, the per-page accounting of dma pins is accomplished via the 3rd struct page in the compound page. In order to support debugging of any pin_user_pages()- related problems, enhance dump_page() so as to report the pin count in that case. Documentation/core-api/pin_user_pages.rst is also updated accordingly. Link: http://lkml.kernel.org/r/20200211001536.1027652-13-jhubbard@nvidia.com Signed-off-by: John Hubbard Acked-by: Kirill A. Shutemov Cc: Jan Kara Cc: Matthew Wilcox Cc: Ira Weiny Cc: J=C3=A9r=C3=B4me Glisse Cc: Al Viro Cc: Christoph Hellwig Cc: Dan Williams Cc: Dave Chinner Cc: Jason Gunthorpe Cc: Jonathan Corbet Cc: Michal Hocko Cc: Mike Kravetz Cc: Shuah Khan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- Documentation/core-api/pin_user_pages.rst | 7 ++++++ mm/debug.c | 21 +++++++++++++++----- 2 files changed, 23 insertions(+), 5 deletions(-) --- a/Documentation/core-api/pin_user_pages.rst~mm-dump_page-additional-dia= gnostics-for-huge-pinned-pages +++ a/Documentation/core-api/pin_user_pages.rst @@ -238,6 +238,13 @@ long-term [R]DMA pins in place, or durin (...unless it was already out of balance due to a long-term RDMA pin being= in place.) =20 +Other diagnostics +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D + +dump_page() has been enhanced slightly, to handle these new counting field= s, and +to better report on compound pages in general. Specifically, for compound = pages +with order > 1, the exact (hpage_pinned_refcount) pincount is reported. + References =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 --- a/mm/debug.c~mm-dump_page-additional-diagnostics-for-huge-pinned-pages +++ a/mm/debug.c @@ -85,11 +85,22 @@ void __dump_page(struct page *page, cons mapcount =3D PageSlab(head) ? 0 : page_mapcount(page); =20 if (compound) - pr_warn("page:%px refcount:%d mapcount:%d mapping:%p " - "index:%#lx head:%px order:%u compound_mapcount:%d\n", - page, page_ref_count(head), mapcount, - mapping, page_to_pgoff(page), head, - compound_order(head), compound_mapcount(page)); + if (hpage_pincount_available(page)) { + pr_warn("page:%px refcount:%d mapcount:%d mapping:%p " + "index:%#lx head:%px order:%u " + "compound_mapcount:%d compound_pincount:%d\n", + page, page_ref_count(head), mapcount, + mapping, page_to_pgoff(page), head, + compound_order(head), compound_mapcount(page), + compound_pincount(page)); + } else { + pr_warn("page:%px refcount:%d mapcount:%d mapping:%p " + "index:%#lx head:%px order:%u " + "compound_mapcount:%d\n", + page, page_ref_count(head), mapcount, + mapping, page_to_pgoff(page), head, + compound_order(head), compound_mapcount(page)); + } else pr_warn("page:%px refcount:%d mapcount:%d mapping:%p index:%#lx\n", page, page_ref_count(page), mapcount, _