From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id 433296B0278 for ; Fri, 23 Sep 2016 04:18:20 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id w84so9706991wmg.1 for ; Fri, 23 Sep 2016 01:18:20 -0700 (PDT) Received: from mail-wm0-f68.google.com (mail-wm0-f68.google.com. [74.125.82.68]) by mx.google.com with ESMTPS id t11si623721wmf.23.2016.09.23.01.18.19 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 23 Sep 2016 01:18:19 -0700 (PDT) Received: by mail-wm0-f68.google.com with SMTP id l132so1481493wmf.1 for ; Fri, 23 Sep 2016 01:18:19 -0700 (PDT) Date: Fri, 23 Sep 2016 10:18:17 +0200 From: Michal Hocko Subject: Re: [RFC] remove unnecessary condition in remove_inode_hugepages Message-ID: <20160923081817.GC4478@dhcp22.suse.cz> References: <57E48B30.2000303@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <57E48B30.2000303@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: zhong jiang Cc: Mike Kravetz , David Rientjes , Vlastimil Babka , Hugh Dickins , Linux Memory Management List , LKML , Naoya Horiguchi [CC Naoya] On Fri 23-09-16 09:53:52, zhong jiang wrote: > > 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); > > > -- > 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 -- Michal Hocko SUSE Labs -- 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