From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx103.postini.com [74.125.245.103]) by kanga.kvack.org (Postfix) with SMTP id 5A57A6B004D for ; Wed, 21 Mar 2012 17:00:21 -0400 (EDT) Date: Wed, 21 Mar 2012 14:00:19 -0700 From: Andrew Morton Subject: Re: [PATCH] mm: hugetlb: bail out unmapping after serving reference page Message-Id: <20120321140019.9ca39a31.akpm@linux-foundation.org> In-Reply-To: <20120223121238.b597e7e4.akpm@linux-foundation.org> References: <20120222130659.d75b6f69.akpm@linux-foundation.org> <20120223121238.b597e7e4.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hillf Danton , Linux-MM , LKML , Michal Hocko , KAMEZAWA Hiroyuki , Hugh Dickins On Thu, 23 Feb 2012 12:12:38 -0800 Andrew Morton wrote: > On Thu, 23 Feb 2012 21:05:41 +0800 > Hillf Danton wrote: > > > and a follow-up cleanup also attached. > > Please, never put more than one patches in an email - it is rather a > pain to manually unpick everything. > > > When unmapping given VM range, a couple of code duplicate, such as pte_page() > > and huge_pte_none(), so a cleanup needed to compact them together. > > > > Signed-off-by: Hillf Danton > > --- > > > > --- a/mm/hugetlb.c Thu Feb 23 20:13:06 2012 > > +++ b/mm/hugetlb.c Thu Feb 23 20:30:16 2012 > > @@ -2245,16 +2245,23 @@ void __unmap_hugepage_range(struct vm_ar > > if (huge_pmd_unshare(mm, &address, ptep)) > > continue; > > > > + pte = huge_ptep_get(ptep); > > + if (huge_pte_none(pte)) > > + continue; > > + > > + /* > > + * HWPoisoned hugepage is already unmapped and dropped reference > > + */ > > + if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) > > + continue; > > + > > + page = pte_page(pte); > > /* > > * If a reference page is supplied, it is because a specific > > * page is being unmapped, not a range. Ensure the page we > > * are about to unmap is the actual page of interest. > > */ > > if (ref_page) { > > - pte = huge_ptep_get(ptep); > > - if (huge_pte_none(pte)) > > - continue; > > - page = pte_page(pte); > > if (page != ref_page) > > continue; > > > > @@ -2267,16 +2274,6 @@ void __unmap_hugepage_range(struct vm_ar > > } > > > > pte = huge_ptep_get_and_clear(mm, address, ptep); > > - if (huge_pte_none(pte)) > > - continue; > > - > > - /* > > - * HWPoisoned hugepage is already unmapped and dropped reference > > - */ > > - if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) > > - continue; > > - > > - page = pte_page(pte); > > if (pte_dirty(pte)) > > set_page_dirty(page); > > list_add(&page->lru, &page_list); > > This changes behaviour when ref_page refers to a hwpoisoned page. Respond, please? -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org