From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f197.google.com (mail-wj0-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 0B0BB6B0069 for ; Mon, 12 Dec 2016 16:02:13 -0500 (EST) Received: by mail-wj0-f197.google.com with SMTP id hb5so29255198wjc.2 for ; Mon, 12 Dec 2016 13:02:12 -0800 (PST) Received: from mail-wm0-x242.google.com (mail-wm0-x242.google.com. [2a00:1450:400c:c09::242]) by mx.google.com with ESMTPS id s10si46360597wjo.159.2016.12.12.13.02.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 12 Dec 2016 13:02:11 -0800 (PST) Received: by mail-wm0-x242.google.com with SMTP id g23so13879387wme.1 for ; Mon, 12 Dec 2016 13:02:11 -0800 (PST) Date: Tue, 13 Dec 2016 00:02:09 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCH 2/2] mm/thp/pagecache/collapse: Free the pte page table on collapse for thp page cache. Message-ID: <20161212210209.GC10202@node.shutemov.name> References: <20161212163428.6780-1-aneesh.kumar@linux.vnet.ibm.com> <20161212163428.6780-2-aneesh.kumar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161212163428.6780-2-aneesh.kumar@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Aneesh Kumar K.V" Cc: akpm@linux-foundation.org, "Kirill A . Shutemov" , mpe@ellerman.id.au, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Mon, Dec 12, 2016 at 10:04:28PM +0530, Aneesh Kumar K.V wrote: > With THP page cache, when trying to build a huge page from regular pte pages, > we just clear the pmd entry. We will take another fault and at that point we > will find the huge page in the radix tree, thereby using the huge page to > complete the page fault > > The second fault path will allocate the needed pgtable_t page for archs like > ppc64. So no need to deposit the same in collapse path. Depositing them in > the collapse path resulting in a pgtable_t memory leak also giving errors like > "[ 2362.021762] BUG: non-zero nr_ptes on freeing mm: 3" > > Fixes:"mm: THP page cache support for ppc64" > > Signed-off-by: Aneesh Kumar K.V Acked-by: Kirill A. Shutemov -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org