Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752832AbaA3J7M (ORCPT ); Thu, 30 Jan 2014 04:59:12 -0500 Received: from cantor2.suse.de ([195.135.220.15]:37894 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751156AbaA3J7K (ORCPT ); Thu, 30 Jan 2014 04:59:10 -0500 Date: Thu, 30 Jan 2014 10:59:07 +0100 From: Michal Hocko To: Davidlohr Bueso Cc: Andrew Morton , Sasha Levin , "Kirill A. Shutemov" , Jonathan Gonzalez , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm, hugetlb: gimme back my page Message-ID: <20140130095907.GA13574@dhcp22.suse.cz> References: <1391063823.2931.3.camel@buesod1.americas.hpqcorp.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1391063823.2931.3.camel@buesod1.americas.hpqcorp.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 29-01-14 22:37:03, Davidlohr Bueso wrote: > From: Davidlohr Bueso > > While testing some changes, I noticed an issue triggered by the libhugetlbfs > test-suite. This is caused by commit 309381fe (mm: dump page when hitting a > VM_BUG_ON using VM_BUG_ON_PAGE), where an application can unexpectedly OOM due > to another program that using, or reserving, pool_size-1 pages later triggers > a VM_BUG_ON_PAGE and thus greedly leaves no memory to the rest of the hugetlb > aware tasks. For example, in libhugetlbfs 2.14: > > mmap-gettest 10 32783 (2M: 64): <---- hit VM_BUG_ON_PAGE > mmap-cow 32782 32783 (2M: 32): FAIL Failed to create shared mapping: Cannot allocate memory > mmap-cow 32782 32783 (2M: 64): FAIL Failed to create shared mapping: Cannot allocate memory > > While I have not looked into why 'mmap-gettest' keeps failing, it is of no > importance to this particular issue. This problem is similar to why we have > the hugetlb_instantiation_mutex, hugepages are quite finite. > > Revert the use of VM_BUG_ON_PAGE back to just VM_BUG_ON. I do not understand what VM_BUG_ON_PAGE has to do with the above failure. Could you be more specific. Hmm, now that I am looking into dump_page_badflags it shouldn't call mem_cgroup_print_bad_page for hugetlb pages because it doesn't make any sense. I will post a patch for that but that still doesn't explain the above changelog. > Signed-off-by: Davidlohr Bueso > --- > include/linux/hugetlb.h | 3 +-- > include/linux/hugetlb_cgroup.h | 5 ++--- > mm/hugetlb.c | 10 +++++----- > mm/hugetlb_cgroup.c | 2 +- > 4 files changed, 9 insertions(+), 11 deletions(-) > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > index 8c43cc4..d01cc97 100644 > --- a/include/linux/hugetlb.h > +++ b/include/linux/hugetlb.h > @@ -2,7 +2,6 @@ > #define _LINUX_HUGETLB_H > > #include > -#include > #include > #include > #include > @@ -355,7 +354,7 @@ static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma, > > static inline struct hstate *page_hstate(struct page *page) > { > - VM_BUG_ON_PAGE(!PageHuge(page), page); > + VM_BUG_ON(!PageHuge(page)); > return size_to_hstate(PAGE_SIZE << compound_order(page)); > } > > diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h > index 787bba3..ce8217f 100644 > --- a/include/linux/hugetlb_cgroup.h > +++ b/include/linux/hugetlb_cgroup.h > @@ -15,7 +15,6 @@ > #ifndef _LINUX_HUGETLB_CGROUP_H > #define _LINUX_HUGETLB_CGROUP_H > > -#include > #include > > struct hugetlb_cgroup; > @@ -29,7 +28,7 @@ struct hugetlb_cgroup; > > static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) > { > - VM_BUG_ON_PAGE(!PageHuge(page), page); > + VM_BUG_ON(!PageHuge(page)); > > if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER) > return NULL; > @@ -39,7 +38,7 @@ static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) > static inline > int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg) > { > - VM_BUG_ON_PAGE(!PageHuge(page), page); > + VM_BUG_ON(!PageHuge(page)); > > if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER) > return -1; > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index c01cb9f..04306b9 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -584,7 +584,7 @@ static void update_and_free_page(struct hstate *h, struct page *page) > 1 << PG_active | 1 << PG_reserved | > 1 << PG_private | 1 << PG_writeback); > } > - VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page); > + VM_BUG_ON(hugetlb_cgroup_from_page(page)); > set_compound_page_dtor(page, NULL); > set_page_refcounted(page); > arch_release_hugepage(page); > @@ -1089,7 +1089,7 @@ retry: > * no users -- drop the buddy allocator's reference. > */ > put_page_testzero(page); > - VM_BUG_ON_PAGE(page_count(page), page); > + VM_BUG_ON(page_count(page)); > enqueue_huge_page(h, page); > } > free: > @@ -3503,7 +3503,7 @@ int dequeue_hwpoisoned_huge_page(struct page *hpage) > > bool isolate_huge_page(struct page *page, struct list_head *list) > { > - VM_BUG_ON_PAGE(!PageHead(page), page); > + VM_BUG_ON(!PageHead(page)); > if (!get_page_unless_zero(page)) > return false; > spin_lock(&hugetlb_lock); > @@ -3514,7 +3514,7 @@ bool isolate_huge_page(struct page *page, struct list_head *list) > > void putback_active_hugepage(struct page *page) > { > - VM_BUG_ON_PAGE(!PageHead(page), page); > + VM_BUG_ON(!PageHead(page)); > spin_lock(&hugetlb_lock); > list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist); > spin_unlock(&hugetlb_lock); > @@ -3523,7 +3523,7 @@ void putback_active_hugepage(struct page *page) > > bool is_hugepage_active(struct page *page) > { > - VM_BUG_ON_PAGE(!PageHuge(page), page); > + VM_BUG_ON(!PageHuge(page)); > /* > * This function can be called for a tail page because the caller, > * scan_movable_pages, scans through a given pfn-range which typically > diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c > index cb00829..d747a84 100644 > --- a/mm/hugetlb_cgroup.c > +++ b/mm/hugetlb_cgroup.c > @@ -390,7 +390,7 @@ void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage) > if (hugetlb_cgroup_disabled()) > return; > > - VM_BUG_ON_PAGE(!PageHuge(oldhpage), oldhpage); > + VM_BUG_ON(!PageHuge(oldhpage)); > spin_lock(&hugetlb_lock); > h_cg = hugetlb_cgroup_from_page(oldhpage); > set_hugetlb_cgroup(oldhpage, NULL); > -- > 1.8.1.4 > > > > -- > 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 from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/