[PATCH v6 05/10] mm/memory_hotplug: Shrink zones when offlining memory
Oscar Salvador
osalvador at suse.de
Wed Dec 4 02:10:30 AEDT 2019
On Sun, Oct 06, 2019 at 10:56:41AM +0200, David Hildenbrand wrote:
> Fixes: d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug")
> Signed-off-by: David Hildenbrand <david at redhat.com>
I did not see anything wrong with the taken approach, and makes sense to me.
The only thing that puzzles me is we seem to not balance spanned_pages
for ZONE_DEVICE anymore.
memremap_pages() increments them via move_pfn_range_to_zone, but we skip
ZONE_DEVICE in remove_pfn_range_from_zone.
That is not really related to this patch, so I might be missing something,
but it caught my eye while reviewing this.
Anyway, for this one:
Reviewed-by: Oscar Salvador <osalvador at suse.de>
off-topic: I __think__ we really need to trim the CC list.
> ---
> arch/arm64/mm/mmu.c | 4 +---
> arch/ia64/mm/init.c | 4 +---
> arch/powerpc/mm/mem.c | 3 +--
> arch/s390/mm/init.c | 4 +---
> arch/sh/mm/init.c | 4 +---
> arch/x86/mm/init_32.c | 4 +---
> arch/x86/mm/init_64.c | 4 +---
> include/linux/memory_hotplug.h | 7 +++++--
> mm/memory_hotplug.c | 31 ++++++++++++++++---------------
> mm/memremap.c | 2 +-
> 10 files changed, 29 insertions(+), 38 deletions(-)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index 60c929f3683b..d10247fab0fd 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1069,7 +1069,6 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> /*
> * FIXME: Cleanup page tables (also in arch_add_memory() in case
> @@ -1078,7 +1077,6 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> * unplug. ARCH_ENABLE_MEMORY_HOTREMOVE must not be
> * unlocked yet.
> */
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(start_pfn, nr_pages, altmap);
> }
> #endif
> diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
> index bf9df2625bc8..a6dd80a2c939 100644
> --- a/arch/ia64/mm/init.c
> +++ b/arch/ia64/mm/init.c
> @@ -689,9 +689,7 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(start_pfn, nr_pages, altmap);
> }
> #endif
> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
> index be941d382c8d..97e5922cb52e 100644
> --- a/arch/powerpc/mm/mem.c
> +++ b/arch/powerpc/mm/mem.c
> @@ -130,10 +130,9 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap);
> int ret;
>
> - __remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
> + __remove_pages(start_pfn, nr_pages, altmap);
>
> /* Remove htab bolted mappings for this section of memory */
> start = (unsigned long)__va(start);
> diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> index a124f19f7b3c..c1d96e588152 100644
> --- a/arch/s390/mm/init.c
> +++ b/arch/s390/mm/init.c
> @@ -291,10 +291,8 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(start_pfn, nr_pages, altmap);
> vmem_remove_mapping(start, size);
> }
> #endif /* CONFIG_MEMORY_HOTPLUG */
> diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
> index dfdbaa50946e..d1b1ff2be17a 100644
> --- a/arch/sh/mm/init.c
> +++ b/arch/sh/mm/init.c
> @@ -434,9 +434,7 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = PFN_DOWN(start);
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(start_pfn, nr_pages, altmap);
> }
> #endif /* CONFIG_MEMORY_HOTPLUG */
> diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
> index 930edeb41ec3..0a74407ef92e 100644
> --- a/arch/x86/mm/init_32.c
> +++ b/arch/x86/mm/init_32.c
> @@ -865,10 +865,8 @@ void arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct zone *zone;
>
> - zone = page_zone(pfn_to_page(start_pfn));
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(start_pfn, nr_pages, altmap);
> }
> #endif
>
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index a6b5c653727b..b8541d77452c 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -1212,10 +1212,8 @@ void __ref arch_remove_memory(int nid, u64 start, u64 size,
> {
> unsigned long start_pfn = start >> PAGE_SHIFT;
> unsigned long nr_pages = size >> PAGE_SHIFT;
> - struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap);
> - struct zone *zone = page_zone(page);
>
> - __remove_pages(zone, start_pfn, nr_pages, altmap);
> + __remove_pages(start_pfn, nr_pages, altmap);
> kernel_physical_mapping_remove(start, start + size);
> }
> #endif /* CONFIG_MEMORY_HOTPLUG */
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index bc477e98a310..517b70943732 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -126,8 +126,8 @@ static inline bool movable_node_is_enabled(void)
>
> extern void arch_remove_memory(int nid, u64 start, u64 size,
> struct vmem_altmap *altmap);
> -extern void __remove_pages(struct zone *zone, unsigned long start_pfn,
> - unsigned long nr_pages, struct vmem_altmap *altmap);
> +extern void __remove_pages(unsigned long start_pfn, unsigned long nr_pages,
> + struct vmem_altmap *altmap);
>
> /* reasonably generic interface to expand the physical pages */
> extern int __add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
> @@ -346,6 +346,9 @@ extern int add_memory(int nid, u64 start, u64 size);
> extern int add_memory_resource(int nid, struct resource *resource);
> extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
> unsigned long nr_pages, struct vmem_altmap *altmap);
> +extern void remove_pfn_range_from_zone(struct zone *zone,
> + unsigned long start_pfn,
> + unsigned long nr_pages);
> extern bool is_memblock_offlined(struct memory_block *mem);
> extern int sparse_add_section(int nid, unsigned long pfn,
> unsigned long nr_pages, struct vmem_altmap *altmap);
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index f96608d24f6a..5b003ffa5dc9 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -457,8 +457,9 @@ static void update_pgdat_span(struct pglist_data *pgdat)
> pgdat->node_spanned_pages = node_end_pfn - node_start_pfn;
> }
>
> -static void __remove_zone(struct zone *zone, unsigned long start_pfn,
> - unsigned long nr_pages)
> +void __ref remove_pfn_range_from_zone(struct zone *zone,
> + unsigned long start_pfn,
> + unsigned long nr_pages)
> {
> struct pglist_data *pgdat = zone->zone_pgdat;
> unsigned long flags;
> @@ -473,28 +474,30 @@ static void __remove_zone(struct zone *zone, unsigned long start_pfn,
> return;
> #endif
>
> + clear_zone_contiguous(zone);
> +
> pgdat_resize_lock(zone->zone_pgdat, &flags);
> shrink_zone_span(zone, start_pfn, start_pfn + nr_pages);
> update_pgdat_span(pgdat);
> pgdat_resize_unlock(zone->zone_pgdat, &flags);
> +
> + set_zone_contiguous(zone);
> }
>
> -static void __remove_section(struct zone *zone, unsigned long pfn,
> - unsigned long nr_pages, unsigned long map_offset,
> - struct vmem_altmap *altmap)
> +static void __remove_section(unsigned long pfn, unsigned long nr_pages,
> + unsigned long map_offset,
> + struct vmem_altmap *altmap)
> {
> struct mem_section *ms = __nr_to_section(pfn_to_section_nr(pfn));
>
> if (WARN_ON_ONCE(!valid_section(ms)))
> return;
>
> - __remove_zone(zone, pfn, nr_pages);
> sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap);
> }
>
> /**
> - * __remove_pages() - remove sections of pages from a zone
> - * @zone: zone from which pages need to be removed
> + * __remove_pages() - remove sections of pages
> * @pfn: starting pageframe (must be aligned to start of a section)
> * @nr_pages: number of pages to remove (must be multiple of section size)
> * @altmap: alternative device page map or %NULL if default memmap is used
> @@ -504,16 +507,14 @@ static void __remove_section(struct zone *zone, unsigned long pfn,
> * sure that pages are marked reserved and zones are adjust properly by
> * calling offline_pages().
> */
> -void __remove_pages(struct zone *zone, unsigned long pfn,
> - unsigned long nr_pages, struct vmem_altmap *altmap)
> +void __remove_pages(unsigned long pfn, unsigned long nr_pages,
> + struct vmem_altmap *altmap)
> {
> unsigned long map_offset = 0;
> unsigned long nr, start_sec, end_sec;
>
> map_offset = vmem_altmap_offset(altmap);
>
> - clear_zone_contiguous(zone);
> -
> if (check_pfn_span(pfn, nr_pages, "remove"))
> return;
>
> @@ -525,13 +526,11 @@ void __remove_pages(struct zone *zone, unsigned long pfn,
> cond_resched();
> pfns = min(nr_pages, PAGES_PER_SECTION
> - (pfn & ~PAGE_SECTION_MASK));
> - __remove_section(zone, pfn, pfns, map_offset, altmap);
> + __remove_section(pfn, pfns, map_offset, altmap);
> pfn += pfns;
> nr_pages -= pfns;
> map_offset = 0;
> }
> -
> - set_zone_contiguous(zone);
> }
>
> int set_online_page_callback(online_page_callback_t callback)
> @@ -859,6 +858,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
> (unsigned long long) pfn << PAGE_SHIFT,
> (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1);
> memory_notify(MEM_CANCEL_ONLINE, &arg);
> + remove_pfn_range_from_zone(zone, pfn, nr_pages);
> mem_hotplug_done();
> return ret;
> }
> @@ -1605,6 +1605,7 @@ static int __ref __offline_pages(unsigned long start_pfn,
> writeback_set_ratelimit();
>
> memory_notify(MEM_OFFLINE, &arg);
> + remove_pfn_range_from_zone(zone, start_pfn, nr_pages);
> mem_hotplug_done();
> return 0;
>
> diff --git a/mm/memremap.c b/mm/memremap.c
> index 8c2fb44c3b4d..70263e6f093e 100644
> --- a/mm/memremap.c
> +++ b/mm/memremap.c
> @@ -140,7 +140,7 @@ void memunmap_pages(struct dev_pagemap *pgmap)
>
> mem_hotplug_begin();
> if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
> - __remove_pages(page_zone(first_page), PHYS_PFN(res->start),
> + __remove_pages(PHYS_PFN(res->start),
> PHYS_PFN(resource_size(res)), NULL);
> } else {
> arch_remove_memory(nid, res->start, resource_size(res),
> --
> 2.21.0
>
--
Oscar Salvador
SUSE L3
More information about the Linuxppc-dev
mailing list