From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx180.postini.com [74.125.245.180]) by kanga.kvack.org (Postfix) with SMTP id F05EF6B006E for ; Tue, 23 Oct 2012 02:54:59 -0400 (EDT) Received: by mail-ia0-f169.google.com with SMTP id h37so3400448iak.14 for ; Mon, 22 Oct 2012 23:54:59 -0700 (PDT) Message-ID: <50863F3D.4070708@gmail.com> Date: Tue, 23 Oct 2012 14:54:53 +0800 From: Ni zhan Chen MIME-Version: 1.0 Subject: Re: [PATCH v2] thp: clean up __collapse_huge_page_isolate References: <1350975002-5927-1-git-send-email-lliubbo@gmail.com> In-Reply-To: <1350975002-5927-1-git-send-email-lliubbo@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Bob Liu Cc: akpm@linux-foundation.org, aarcange@redhat.com, hughd@google.com, rientjes@google.com, xiaoguangrong@linux.vnet.ibm.com, kirill.shutemov@linux.intel.com, linux-mm@kvack.org On 10/23/2012 02:50 PM, Bob Liu wrote: > There are duplicated place using release_pte_pages(). > And release_all_pte_pages() can also be removed. > > v2: mv label out of condition. it seems that the first version has already merged in linux-mm > > Signed-off-by: Bob Liu > --- > mm/huge_memory.c | 38 +++++++++++--------------------------- > 1 file changed, 11 insertions(+), 27 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index a863af2..96a2ccc 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1700,64 +1700,49 @@ static void release_pte_pages(pte_t *pte, pte_t *_pte) > } > } > > -static void release_all_pte_pages(pte_t *pte) > -{ > - release_pte_pages(pte, pte + HPAGE_PMD_NR); > -} > - > static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > unsigned long address, > pte_t *pte) > { > struct page *page; > pte_t *_pte; > - int referenced = 0, isolated = 0, none = 0; > + int referenced = 0, none = 0; > for (_pte = pte; _pte < pte+HPAGE_PMD_NR; > _pte++, address += PAGE_SIZE) { > pte_t pteval = *_pte; > if (pte_none(pteval)) { > if (++none <= khugepaged_max_ptes_none) > continue; > - else { > - release_pte_pages(pte, _pte); > + else > goto out; > - } > } > - if (!pte_present(pteval) || !pte_write(pteval)) { > - release_pte_pages(pte, _pte); > + if (!pte_present(pteval) || !pte_write(pteval)) > goto out; > - } > page = vm_normal_page(vma, address, pteval); > - if (unlikely(!page)) { > - release_pte_pages(pte, _pte); > + if (unlikely(!page)) > goto out; > - } > + > VM_BUG_ON(PageCompound(page)); > BUG_ON(!PageAnon(page)); > VM_BUG_ON(!PageSwapBacked(page)); > > /* cannot use mapcount: can't collapse if there's a gup pin */ > - if (page_count(page) != 1) { > - release_pte_pages(pte, _pte); > + if (page_count(page) != 1) > goto out; > - } > /* > * We can do it before isolate_lru_page because the > * page can't be freed from under us. NOTE: PG_lock > * is needed to serialize against split_huge_page > * when invoked from the VM. > */ > - if (!trylock_page(page)) { > - release_pte_pages(pte, _pte); > + if (!trylock_page(page)) > goto out; > - } > /* > * Isolate the page to avoid collapsing an hugepage > * currently in use by the VM. > */ > if (isolate_lru_page(page)) { > unlock_page(page); > - release_pte_pages(pte, _pte); > goto out; > } > /* 0 stands for page_is_file_cache(page) == false */ > @@ -1770,12 +1755,11 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > mmu_notifier_test_young(vma->vm_mm, address)) > referenced = 1; > } > - if (unlikely(!referenced)) > - release_all_pte_pages(pte); > - else > - isolated = 1; > + if (likely(referenced)) > + return 1; > out: > - return isolated; > + release_pte_pages(pte, _pte); > + return 0; > } > > static void __collapse_huge_page_copy(pte_t *pte, struct page *page, -- 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