Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934909Ab3GSDSt (ORCPT ); Thu, 18 Jul 2013 23:18:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:21292 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759570Ab3GSDSs (ORCPT ); Thu, 18 Jul 2013 23:18:48 -0400 Date: Thu, 18 Jul 2013 23:18:19 -0400 From: Naoya Horiguchi To: Hillf Danton Cc: linux-mm@kvack.org, Andrew Morton , Mel Gorman , Hugh Dickins , KOSAKI Motohiro , Andi Kleen , Michal Hocko , Rik van Riel , "Aneesh Kumar K.V" , linux-kernel@vger.kernel.org, Naoya Horiguchi Message-ID: <1374203899-w7jwqowi-mutt-n-horiguchi@ah.jp.nec.com> In-Reply-To: References: <1374183272-10153-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1374183272-10153-2-git-send-email-n-horiguchi@ah.jp.nec.com> Subject: Re: [PATCH 1/8] migrate: make core migration code aware of hugepage Mime-Version: 1.0 Content-Type: text/plain; charset=iso-2022-jp Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Mutt-References: X-Mutt-Fcc: ~/Maildir/sent/ 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 Content-Length: 6231 Lines: 161 Hello Hillf, Thanks for your reviewing. On Fri, Jul 19, 2013 at 10:38:35AM +0800, Hillf Danton wrote: > Hey Naoya, > > On Fri, Jul 19, 2013 at 5:34 AM, Naoya Horiguchi > wrote: > > Before enabling each user of page migration to support hugepage, > > this patch enables the list of pages for migration to link not only > > LRU pages, but also hugepages. As a result, putback_movable_pages() > > and migrate_pages() can handle both of LRU pages and hugepages. > > > > ChangeLog v3: > > - revert introducing migrate_movable_pages > > - add isolate_huge_page > > > > ChangeLog v2: > > - move code removing VM_HUGETLB from vma_migratable check into a > > separate patch > > - hold hugetlb_lock in putback_active_hugepage > > - update comment near the definition of hugetlb_lock > > > > Signed-off-by: Naoya Horiguchi > > --- > > include/linux/hugetlb.h | 6 ++++++ > > mm/hugetlb.c | 32 +++++++++++++++++++++++++++++++- > > mm/migrate.c | 10 +++++++++- > > 3 files changed, 46 insertions(+), 2 deletions(-) > > > > diff --git v3.11-rc1.orig/include/linux/hugetlb.h v3.11-rc1/include/linux/hugetlb.h > > index c2b1801..0b7a9e7 100644 > > --- v3.11-rc1.orig/include/linux/hugetlb.h > > +++ v3.11-rc1/include/linux/hugetlb.h > > @@ -66,6 +66,9 @@ int hugetlb_reserve_pages(struct inode *inode, long from, long to, > > vm_flags_t vm_flags); > > 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 *l); > > +void putback_active_hugepage(struct page *page); > > +void putback_active_hugepages(struct list_head *l); > > void copy_huge_page(struct page *dst, struct page *src); > > > > #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE > > @@ -134,6 +137,9 @@ static inline int dequeue_hwpoisoned_huge_page(struct page *page) > > return 0; > > } > > > > +#define isolate_huge_page(p, l) false > > +#define putback_active_hugepage(p) > > Add do{}while(o), ok? OK. And I will get the same comment for patch 7/8. > > +#define putback_active_hugepages(l) > > static inline void copy_huge_page(struct page *dst, struct page *src) > > { > > } > > diff --git v3.11-rc1.orig/mm/hugetlb.c v3.11-rc1/mm/hugetlb.c > > index 83aff0a..4c48a70 100644 > > --- v3.11-rc1.orig/mm/hugetlb.c > > +++ v3.11-rc1/mm/hugetlb.c > > @@ -48,7 +48,8 @@ static unsigned long __initdata default_hstate_max_huge_pages; > > static unsigned long __initdata default_hstate_size; > > > > /* > > - * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages > > + * Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages, > > + * free_huge_pages, and surplus_huge_pages. > > */ > > DEFINE_SPINLOCK(hugetlb_lock); > > > > @@ -3431,3 +3432,32 @@ int dequeue_hwpoisoned_huge_page(struct page *hpage) > > return ret; > > } > > #endif > > + > > +bool isolate_huge_page(struct page *page, struct list_head *l) > > Can we replace the page parameter with p? Yes. Maybe it's strange to use the full name "page" for one parameter and an extremely shortened one "l" for another one. > > +{ > > + VM_BUG_ON(!PageHead(page)); > > + if (!get_page_unless_zero(page)) > > + return false; > > + spin_lock(&hugetlb_lock); > > + list_move_tail(&page->lru, l); > > + spin_unlock(&hugetlb_lock); > > + return true; > > +} > > + > > +void putback_active_hugepage(struct 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); > > + put_page(page); > > +} > > + > > +void putback_active_hugepages(struct list_head *l) > > +{ > > + struct page *page; > > + struct page *page2; > > + > > + list_for_each_entry_safe(page, page2, l, lru) > > + putback_active_hugepage(page); > > Can we acquire hugetlb_lock only once? I'm not sure which is the best. In general, fine-grained locking is preferred because other lock contenders wait less. Could you tell some specific reason to hold lock outside the loop? > > +} > > diff --git v3.11-rc1.orig/mm/migrate.c v3.11-rc1/mm/migrate.c > > index 6f0c244..b44a067 100644 > > --- v3.11-rc1.orig/mm/migrate.c > > +++ v3.11-rc1/mm/migrate.c > > @@ -100,6 +100,10 @@ void putback_movable_pages(struct list_head *l) > > struct page *page2; > > > > list_for_each_entry_safe(page, page2, l, lru) { > > + if (unlikely(PageHuge(page))) { > > + putback_active_hugepage(page); > > + continue; > > + } > > list_del(&page->lru); > > dec_zone_page_state(page, NR_ISOLATED_ANON + > > page_is_file_cache(page)); > > @@ -1025,7 +1029,11 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > > list_for_each_entry_safe(page, page2, from, lru) { > > cond_resched(); > > > > - rc = unmap_and_move(get_new_page, private, > > + if (PageHuge(page)) > > + rc = unmap_and_move_huge_page(get_new_page, > > + private, page, pass > 2, mode); > > + else > > + rc = unmap_and_move(get_new_page, private, > > page, pass > 2, mode); > > > Is this hunk unclean merge? Sorry, I don't catch the point. This patch is based on v3.11-rc1 and the present HEAD has no changes from that release. Or do you mean that other trees have some conflicts? (my brief checking on -mm/-next didn't find that...) Thanks, Naoya Horiguchi -- 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/