From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua0-f198.google.com (mail-ua0-f198.google.com [209.85.217.198]) by kanga.kvack.org (Postfix) with ESMTP id 71A90280259 for ; Tue, 27 Sep 2016 15:24:02 -0400 (EDT) Received: by mail-ua0-f198.google.com with SMTP id l16so1834673uaa.3 for ; Tue, 27 Sep 2016 12:24:02 -0700 (PDT) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id j186si1019466vkh.56.2016.09.27.12.24.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Sep 2016 12:24:01 -0700 (PDT) Subject: Re: [PATCH v2] mm: remove unnecessary condition in remove_inode_hugepages References: <1474985786-5052-1-git-send-email-zhongjiang@huawei.com> From: Mike Kravetz Message-ID: <63e015fd-3920-9753-fb58-c11d95d61d8b@oracle.com> Date: Tue, 27 Sep 2016 12:23:17 -0700 MIME-Version: 1.0 In-Reply-To: <1474985786-5052-1-git-send-email-zhongjiang@huawei.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: zhongjiang , mhocko@kernel.org, akpm@linux-foundation.org Cc: linux-mm@kvack.org, n-horiguchi@ah.jp.nec.com On 09/27/2016 07:16 AM, zhongjiang wrote: > From: zhong jiang > > when the huge page is added to the page cahce (huge_add_to_page_cache), > the page private flag will be cleared. since this code > (remove_inode_hugepages) will only be called for pages in the > page cahce, PagePrivate(page) will always be false. > > The patch remove the code without any functional change. > > Signed-off-by: zhong jiang > --- > fs/hugetlbfs/inode.c | 11 +++++------ > include/linux/hugetlb.h | 2 +- > mm/hugetlb.c | 4 ++-- > 3 files changed, 8 insertions(+), 9 deletions(-) > > diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c > index 4ea71eb..40d0afe 100644 > --- a/fs/hugetlbfs/inode.c > +++ b/fs/hugetlbfs/inode.c > @@ -458,18 +458,17 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart, > * cache (remove_huge_page) BEFORE removing the > * region/reserve map (hugetlb_unreserve_pages). In > * rare out of memory conditions, removal of the > - * region/reserve map could fail. Before free'ing > - * the page, note PagePrivate which is used in case > - * of error. > + * region/reserve map could fail. Correspondingly, > + * the subpool and global reserve usage count can need > + * to be adjusted. > */ > - rsv_on_error = !PagePrivate(page); > + VM_BUG_ON(PagePrivate(page)); > remove_huge_page(page); > freed++; > if (!truncate_op) { > if (unlikely(hugetlb_unreserve_pages(inode, > next, next + 1, 1))) > - hugetlb_fix_reserve_counts(inode, > - rsv_on_error); > + hugetlb_fix_reserve_counts(inode); > } > > unlock_page(page); > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > index c26d463..d2e0fc5 100644 > --- a/include/linux/hugetlb.h > +++ b/include/linux/hugetlb.h > @@ -90,7 +90,7 @@ int dequeue_hwpoisoned_huge_page(struct page *page); > bool isolate_huge_page(struct page *page, struct list_head *list); > void putback_active_hugepage(struct page *page); > void free_huge_page(struct page *page); > -void hugetlb_fix_reserve_counts(struct inode *inode, bool restore_reserve); > +void hugetlb_fix_reserve_counts(struct inode *inode); > extern struct mutex *hugetlb_fault_mutex_table; > u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm, > struct vm_area_struct *vma, > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 87e11d8..28a079a 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -567,13 +567,13 @@ retry: > * appear as a "reserved" entry instead of simply dangling with incorrect > * counts. > */ > -void hugetlb_fix_reserve_counts(struct inode *inode, bool restore_reserve) > +void hugetlb_fix_reserve_counts(struct inode *inode) > { > struct hugepage_subpool *spool = subpool_inode(inode); > long rsv_adjust; > > rsv_adjust = hugepage_subpool_get_pages(spool, 1); > - if (restore_reserve && rsv_adjust) { > + if (rsv_adjust) { > struct hstate *h = hstate_inode(inode); > > hugetlb_acct_memory(h, 1); > Reviewed-by: Mike Kravetz Tested-by: Mike Kravetz -- Mike Kravetz -- 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