Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754652AbbHXPEr (ORCPT ); Mon, 24 Aug 2015 11:04:47 -0400 Received: from mx2.suse.de ([195.135.220.15]:58565 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753727AbbHXPEq (ORCPT ); Mon, 24 Aug 2015 11:04:46 -0400 Subject: Re: [PATCHv3 2/5] zsmalloc: use page->private instead of page->first_page To: "Kirill A. Shutemov" , Andrew Morton , Hugh Dickins References: <1439976106-137226-1-git-send-email-kirill.shutemov@linux.intel.com> <1439976106-137226-3-git-send-email-kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli , Dave Hansen , Johannes Weiner , Michal Hocko , David Rientjes , linux-kernel@vger.kernel.org, linux-mm@kvack.org From: Vlastimil Babka Message-ID: <55DB328B.2010205@suse.cz> Date: Mon, 24 Aug 2015 17:04:43 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <1439976106-137226-3-git-send-email-kirill.shutemov@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3065 Lines: 78 On 08/19/2015 11:21 AM, Kirill A. Shutemov wrote: > We are going to rework how compound_head() work. It will not use > page->first_page as we have it now. > > The only other user of page->fisrt_page beyond compound pages is ^ typo > zsmalloc. > > Let's use page->private instead of page->first_page here. It occupies > the same storage space. > > Signed-off-by: Kirill A. Shutemov Acked-by: Vlastimil Babka > --- > mm/zsmalloc.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c > index 0a7f81aa2249..a85754e69879 100644 > --- a/mm/zsmalloc.c > +++ b/mm/zsmalloc.c > @@ -16,7 +16,7 @@ > * struct page(s) to form a zspage. > * > * Usage of struct page fields: > - * page->first_page: points to the first component (0-order) page > + * page->private: points to the first component (0-order) page > * page->index (union with page->freelist): offset of the first object > * starting in this page. For the first page, this is > * always 0, so we use this field (aka freelist) to point > @@ -26,8 +26,7 @@ > * > * For _first_ page only: > * > - * page->private (union with page->first_page): refers to the > - * component page after the first page > + * page->private: refers to the component page after the first page > * If the page is first_page for huge object, it stores handle. > * Look at size_class->huge. > * page->freelist: points to the first free object in zspage. > @@ -770,7 +769,7 @@ static struct page *get_first_page(struct page *page) > if (is_first_page(page)) > return page; > else > - return page->first_page; > + return (struct page *)page_private(page); > } > > static struct page *get_next_page(struct page *page) > @@ -955,7 +954,7 @@ static struct page *alloc_zspage(struct size_class *class, gfp_t flags) > * Allocate individual pages and link them together as: > * 1. first page->private = first sub-page > * 2. all sub-pages are linked together using page->lru > - * 3. each sub-page is linked to the first page using page->first_page > + * 3. each sub-page is linked to the first page using page->private > * > * For each size class, First/Head pages are linked together using > * page->lru. Also, we set PG_private to identify the first page > @@ -980,7 +979,7 @@ static struct page *alloc_zspage(struct size_class *class, gfp_t flags) > if (i == 1) > set_page_private(first_page, (unsigned long)page); > if (i >= 1) > - page->first_page = first_page; > + set_page_private(first_page, (unsigned long)first_page); > if (i >= 2) > list_add(&page->lru, &prev_page->lru); > if (i == class->pages_per_zspage - 1) /* last page */ > -- 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/