Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754847Ab3CONzc (ORCPT ); Fri, 15 Mar 2013 09:55:32 -0400 Received: from mail-ob0-f171.google.com ([209.85.214.171]:49387 "EHLO mail-ob0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754493Ab3CONz2 (ORCPT ); Fri, 15 Mar 2013 09:55:28 -0400 MIME-Version: 1.0 In-Reply-To: <20130315135026.32B58E0085@blue.fi.intel.com> References: <1363283435-7666-1-git-send-email-kirill.shutemov@linux.intel.com> <1363283435-7666-9-git-send-email-kirill.shutemov@linux.intel.com> <20130315132333.B8205E0085@blue.fi.intel.com> <20130315135026.32B58E0085@blue.fi.intel.com> Date: Fri, 15 Mar 2013 21:55:25 +0800 Message-ID: Subject: Re: [PATCHv2, RFC 08/30] thp, mm: rewrite add_to_page_cache_locked() to support huge pages From: Hillf Danton To: "Kirill A. Shutemov" Cc: Andrea Arcangeli , Andrew Morton , Al Viro , Hugh Dickins , Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1609 Lines: 45 On Fri, Mar 15, 2013 at 9:50 PM, Kirill A. Shutemov wrote: > Hillf Danton wrote: >> On Fri, Mar 15, 2013 at 9:23 PM, Kirill A. Shutemov >> wrote: >> > Hillf Danton wrote: >> >> On Fri, Mar 15, 2013 at 1:50 AM, Kirill A. Shutemov >> >> wrote: >> >> > + page_cache_get(page); >> >> > + spin_lock_irq(&mapping->tree_lock); >> >> > + page->mapping = mapping; >> >> > + page->index = offset; >> >> > + error = radix_tree_insert(&mapping->page_tree, offset, page); >> >> > + if (unlikely(error)) >> >> > + goto err; >> >> > + if (PageTransHuge(page)) { >> >> > + int i; >> >> > + for (i = 1; i < HPAGE_CACHE_NR; i++) { >> >> struct page *tail = page + i; to easy reader >> >> >> >> > + page_cache_get(page + i); >> >> s/page_cache_get/get_page_foll/ ? >> > >> > Why? >> > >> see follow_trans_huge_pmd() please. > > Sorry, I fail to see how follow_trans_huge_pmd() is relevant here. > Could you elaborate? > Lets see the code page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT; //page is tail now VM_BUG_ON(!PageCompound(page)); if (flags & FOLL_GET) get_page_foll(page); //raise page count with the foll function thus I raised question. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/