From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1034064AbcIWB5l (ORCPT ); Thu, 22 Sep 2016 21:57:41 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:57460 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965135AbcIWB5k (ORCPT ); Thu, 22 Sep 2016 21:57:40 -0400 Message-ID: <57E48B30.2000303@huawei.com> Date: Fri, 23 Sep 2016 09:53:52 +0800 From: zhong jiang User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Mike Kravetz , Michal Hocko , David Rientjes , Vlastimil Babka , "Hugh Dickins" CC: Linux Memory Management List , LKML Subject: [RFC] remove unnecessary condition in remove_inode_hugepages Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.68] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020203.57E48B3F.00A3,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 85e4e7b75070b26fc63764715fc3b9fb Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At present, we need to call hugetlb_fix_reserve_count when hugetlb_unrserve_pages fails, and PagePrivate will decide hugetlb reserves counts. we obtain the page from page cache. and use page both lock_page and mutex_lock. alloc_huge_page add page to page chace always hold lock page, then bail out clearpageprivate before unlock page. but I' m not sure it is right or I miss the points. diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 4ea71eb..010723b 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -462,14 +462,12 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart, * the page, note PagePrivate which is used in case * of error. */ - rsv_on_error = !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);