From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sat, 19 Mar 2016 04:02:40 +0300 From: "Kirill A. Shutemov" To: "Aneesh Kumar K.V" Cc: "Kirill A. Shutemov" , Hugh Dickins , Andrea Arcangeli , Andrew Morton , Dave Hansen , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Jerome Marchand , Yang Shi , Sasha Levin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCHv4 08/25] thp: support file pages in zap_huge_pmd() Message-ID: <20160319010239.GB29883@node.shutemov.name> References: <1457737157-38573-1-git-send-email-kirill.shutemov@linux.intel.com> <1457737157-38573-9-git-send-email-kirill.shutemov@linux.intel.com> <87a8lvao4a.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87a8lvao4a.fsf@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: On Fri, Mar 18, 2016 at 07:23:41PM +0530, Aneesh Kumar K.V wrote: > "Kirill A. Shutemov" writes: > > > [ text/plain ] > > split_huge_pmd() for file mappings (and DAX too) is implemented by just > > clearing pmd entry as we can re-fill this area from page cache on pte > > level later. > > > > This means we don't need deposit page tables when file THP is mapped. > > Therefore we shouldn't try to withdraw a page table on zap_huge_pmd() > > file THP PMD. > > Archs like ppc64 use deposited page table to track the hardware page > table slot information. We probably may want to add hooks which arch can > use to achieve the same even with file THP Could you describe more on what kind of information you're talking about? -- 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