From: Michal Hocko <mhocko@kernel.org>
To: David Hildenbrand <david@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linuxppc-dev@lists.ozlabs.org,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Andrew Morton <akpm@linux-foundation.org>,
Oscar Salvador <osalvador@suse.de>, Baoquan He <bhe@redhat.com>,
Wei Yang <richard.weiyang@gmail.com>
Subject: Re: [PATCH v1 2/2] mm/memory_hotplug: remove is_mem_section_removable()
Date: Tue, 7 Apr 2020 16:00:44 +0200 [thread overview]
Message-ID: <20200407140044.GR18914@dhcp22.suse.cz> (raw)
In-Reply-To: <20200407135416.24093-3-david@redhat.com>
On Tue 07-04-20 15:54:16, David Hildenbrand wrote:
> Fortunately, all users of is_mem_section_removable() are gone. Get rid of
> it, including some now unnecessary functions.
>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: Baoquan He <bhe@redhat.com>
> Cc: Wei Yang <richard.weiyang@gmail.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
> ---
> include/linux/memory_hotplug.h | 7 ----
> mm/memory_hotplug.c | 75 ----------------------------------
\o/
Thanks!
> 2 files changed, 82 deletions(-)
>
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index 93d9ada74ddd..7dca9cd6076b 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -314,19 +314,12 @@ static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
>
> #ifdef CONFIG_MEMORY_HOTREMOVE
>
> -extern bool is_mem_section_removable(unsigned long pfn, unsigned long nr_pages);
> extern void try_offline_node(int nid);
> extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
> extern int remove_memory(int nid, u64 start, u64 size);
> extern void __remove_memory(int nid, u64 start, u64 size);
>
> #else
> -static inline bool is_mem_section_removable(unsigned long pfn,
> - unsigned long nr_pages)
> -{
> - return false;
> -}
> -
> static inline void try_offline_node(int nid) {}
>
> static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 47cf6036eb31..4d338d546d52 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1112,81 +1112,6 @@ int add_memory(int nid, u64 start, u64 size)
> EXPORT_SYMBOL_GPL(add_memory);
>
> #ifdef CONFIG_MEMORY_HOTREMOVE
> -/*
> - * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy
> - * set and the size of the free page is given by page_order(). Using this,
> - * the function determines if the pageblock contains only free pages.
> - * Due to buddy contraints, a free page at least the size of a pageblock will
> - * be located at the start of the pageblock
> - */
> -static inline int pageblock_free(struct page *page)
> -{
> - return PageBuddy(page) && page_order(page) >= pageblock_order;
> -}
> -
> -/* Return the pfn of the start of the next active pageblock after a given pfn */
> -static unsigned long next_active_pageblock(unsigned long pfn)
> -{
> - struct page *page = pfn_to_page(pfn);
> -
> - /* Ensure the starting page is pageblock-aligned */
> - BUG_ON(pfn & (pageblock_nr_pages - 1));
> -
> - /* If the entire pageblock is free, move to the end of free page */
> - if (pageblock_free(page)) {
> - int order;
> - /* be careful. we don't have locks, page_order can be changed.*/
> - order = page_order(page);
> - if ((order < MAX_ORDER) && (order >= pageblock_order))
> - return pfn + (1 << order);
> - }
> -
> - return pfn + pageblock_nr_pages;
> -}
> -
> -static bool is_pageblock_removable_nolock(unsigned long pfn)
> -{
> - struct page *page = pfn_to_page(pfn);
> - struct zone *zone;
> -
> - /*
> - * We have to be careful here because we are iterating over memory
> - * sections which are not zone aware so we might end up outside of
> - * the zone but still within the section.
> - * We have to take care about the node as well. If the node is offline
> - * its NODE_DATA will be NULL - see page_zone.
> - */
> - if (!node_online(page_to_nid(page)))
> - return false;
> -
> - zone = page_zone(page);
> - pfn = page_to_pfn(page);
> - if (!zone_spans_pfn(zone, pfn))
> - return false;
> -
> - return !has_unmovable_pages(zone, page, MIGRATE_MOVABLE,
> - MEMORY_OFFLINE);
> -}
> -
> -/* Checks if this range of memory is likely to be hot-removable. */
> -bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages)
> -{
> - unsigned long end_pfn, pfn;
> -
> - end_pfn = min(start_pfn + nr_pages,
> - zone_end_pfn(page_zone(pfn_to_page(start_pfn))));
> -
> - /* Check the starting page of each pageblock within the range */
> - for (pfn = start_pfn; pfn < end_pfn; pfn = next_active_pageblock(pfn)) {
> - if (!is_pageblock_removable_nolock(pfn))
> - return false;
> - cond_resched();
> - }
> -
> - /* All pageblocks in the memory block are likely to be hot-removable */
> - return true;
> -}
> -
> /*
> * Confirm all pages in a range [start, end) belong to the same zone (skipping
> * memory holes). When true, return the zone.
> --
> 2.25.1
>
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2020-04-07 14:00 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-07 13:54 [PATCH v1 0/2] mm/memory_hotplug: remove is_mem_section_removable() David Hildenbrand
2020-04-07 13:54 ` [PATCH v1 1/2] powerpc/pseries/hotplug-memory: stop checking is_mem_section_removable() David Hildenbrand
2020-04-07 13:58 ` Michal Hocko
2020-04-08 2:46 ` Baoquan He
2020-04-09 2:59 ` piliu
2020-04-09 7:26 ` David Hildenbrand
2020-04-09 8:56 ` David Hildenbrand
2020-04-09 14:01 ` piliu
2020-04-09 7:26 ` Michael Ellerman
2020-04-09 7:32 ` David Hildenbrand
2020-04-09 7:59 ` Michal Hocko
2020-04-09 8:12 ` David Hildenbrand
2020-04-09 8:49 ` Michal Hocko
2020-04-07 13:54 ` [PATCH v1 2/2] mm/memory_hotplug: remove is_mem_section_removable() David Hildenbrand
2020-04-07 14:00 ` Michal Hocko [this message]
2020-04-07 21:30 ` Wei Yang
2020-04-08 2:48 ` Baoquan He
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