From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f177.google.com (mail-wi0-f177.google.com [209.85.212.177]) by kanga.kvack.org (Postfix) with ESMTP id 9B4C06B0032 for ; Wed, 1 Apr 2015 12:36:33 -0400 (EDT) Received: by widdi4 with SMTP id di4so51377246wid.0 for ; Wed, 01 Apr 2015 09:36:33 -0700 (PDT) Received: from mail-wg0-x232.google.com (mail-wg0-x232.google.com. [2a00:1450:400c:c00::232]) by mx.google.com with ESMTPS id c17si4902965wib.12.2015.04.01.09.36.31 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 Apr 2015 09:36:32 -0700 (PDT) Received: by wgbdm7 with SMTP id dm7so59560550wgb.1 for ; Wed, 01 Apr 2015 09:36:31 -0700 (PDT) Date: Wed, 1 Apr 2015 18:36:24 +0200 From: Michal Hocko Subject: Re: [PATCH v3 3/3] mm: hugetlb: cleanup using PageHugeActive flag Message-ID: <20150401163624.GC12808@dhcp22.suse.cz> References: <1427791840-11247-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1427791840-11247-4-git-send-email-n-horiguchi@ah.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1427791840-11247-4-git-send-email-n-horiguchi@ah.jp.nec.com> Sender: owner-linux-mm@kvack.org List-ID: To: Naoya Horiguchi Cc: Andrew Morton , Hugh Dickins , Mel Gorman , Johannes Weiner , David Rientjes , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Naoya Horiguchi On Tue 31-03-15 08:50:46, Naoya Horiguchi wrote: > Now we have an easy access to hugepages' activeness, so existing helpers to > get the information can be cleaned up. > > Signed-off-by: Naoya Horiguchi Reviewed-by: Michal Hocko > --- > include/linux/hugetlb.h | 8 ++++++-- > mm/hugetlb.c | 42 +++++------------------------------------- > mm/memory_hotplug.c | 2 +- > 3 files changed, 12 insertions(+), 40 deletions(-) > > diff --git v4.0-rc6.orig/include/linux/hugetlb.h v4.0-rc6/include/linux/hugetlb.h > index 7b5785032049..8494abed02a5 100644 > --- v4.0-rc6.orig/include/linux/hugetlb.h > +++ v4.0-rc6/include/linux/hugetlb.h > @@ -42,6 +42,7 @@ struct hugepage_subpool *hugepage_new_subpool(long nr_blocks); > void hugepage_put_subpool(struct hugepage_subpool *spool); > > int PageHuge(struct page *page); > +int PageHugeActive(struct page *page); > > void reset_vma_resv_huge_pages(struct vm_area_struct *vma); > int hugetlb_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); > @@ -79,7 +80,6 @@ void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed); > 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); > -bool is_hugepage_active(struct page *page); > void free_huge_page(struct page *page); > > #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE > @@ -114,6 +114,11 @@ static inline int PageHuge(struct page *page) > return 0; > } > > +static inline int PageHugeActive(struct page *page) > +{ > + return 0; > +} > + > static inline void reset_vma_resv_huge_pages(struct vm_area_struct *vma) > { > } > @@ -152,7 +157,6 @@ static inline bool isolate_huge_page(struct page *page, struct list_head *list) > return false; > } > #define putback_active_hugepage(p) do {} while (0) > -#define is_hugepage_active(x) false > > static inline unsigned long hugetlb_change_protection(struct vm_area_struct *vma, > unsigned long address, unsigned long end, pgprot_t newprot) > diff --git v4.0-rc6.orig/mm/hugetlb.c v4.0-rc6/mm/hugetlb.c > index 05e0233d30d7..8e1c46affc59 100644 > --- v4.0-rc6.orig/mm/hugetlb.c > +++ v4.0-rc6/mm/hugetlb.c > @@ -3795,20 +3795,6 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address, > > #ifdef CONFIG_MEMORY_FAILURE > > -/* Should be called in hugetlb_lock */ > -static int is_hugepage_on_freelist(struct page *hpage) > -{ > - struct page *page; > - struct page *tmp; > - struct hstate *h = page_hstate(hpage); > - int nid = page_to_nid(hpage); > - > - list_for_each_entry_safe(page, tmp, &h->hugepage_freelists[nid], lru) > - if (page == hpage) > - return 1; > - return 0; > -} > - > /* > * This function is called from memory failure code. > * Assume the caller holds page lock of the head page. > @@ -3820,7 +3806,11 @@ int dequeue_hwpoisoned_huge_page(struct page *hpage) > int ret = -EBUSY; > > spin_lock(&hugetlb_lock); > - if (is_hugepage_on_freelist(hpage)) { > + /* > + * Just checking !PageHugeActive is not enough, because that could be > + * an isolated/hwpoisoned hugepage (which have >0 refcount). > + */ > + if (!PageHugeActive(hpage) && !page_count(hpage)) { > /* > * Hwpoisoned hugepage isn't linked to activelist or freelist, > * but dangling hpage->lru can trigger list-debug warnings > @@ -3864,25 +3854,3 @@ void putback_active_hugepage(struct page *page) > spin_unlock(&hugetlb_lock); > put_page(page); > } > - > -bool is_hugepage_active(struct page *page) > -{ > - VM_BUG_ON_PAGE(!PageHuge(page), page); > - /* > - * This function can be called for a tail page because the caller, > - * scan_movable_pages, scans through a given pfn-range which typically > - * covers one memory block. In systems using gigantic hugepage (1GB > - * for x86_64,) a hugepage is larger than a memory block, and we don't > - * support migrating such large hugepages for now, so return false > - * when called for tail pages. > - */ > - if (PageTail(page)) > - return false; > - /* > - * Refcount of a hwpoisoned hugepages is 1, but they are not active, > - * so we should return false for them. > - */ > - if (unlikely(PageHWPoison(page))) > - return false; > - return page_count(page) > 0; > -} > diff --git v4.0-rc6.orig/mm/memory_hotplug.c v4.0-rc6/mm/memory_hotplug.c > index 65842d688b7c..2d53388c0715 100644 > --- v4.0-rc6.orig/mm/memory_hotplug.c > +++ v4.0-rc6/mm/memory_hotplug.c > @@ -1376,7 +1376,7 @@ static unsigned long scan_movable_pages(unsigned long start, unsigned long end) > if (PageLRU(page)) > return pfn; > if (PageHuge(page)) { > - if (is_hugepage_active(page)) > + if (PageHugeActive(page)) > return pfn; > else > pfn = round_up(pfn + 1, > -- > 1.9.3 -- 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