On 7/28/21 6:56 AM, Dan Williams wrote:
> On Wed, Jul 14, 2021 at 12:36 PM Joao Martins <[email protected]>
> wrote:
>>
>> In support of using compound pages for devmap mappings, plumb the pgmap
>> down to the vmemmap_populate implementation. Note that while altmap is
>> retrievable from pgmap the memory hotplug code passes altmap without
>> pgmap[*], so both need to be independently plumbed.
>>
>> So in addition to @altmap, pass @pgmap to sparse section populate
>> functions namely:
>>
>> sparse_add_section
>> section_activate
>> populate_section_memmap
>> __populate_section_memmap
>>
>> Passing @pgmap allows __populate_section_memmap() to both fetch the
>> geometry in which memmap metadata is created for and also to let
>> sparse-vmemmap fetch pgmap ranges to co-relate to a given section and pick
>> whether to just reuse tail pages from past onlined sections.
>
> Looks good to me, just one quibble below:
>
> Reviewed-by: Dan Williams <[email protected]>
>
Thank you!
>>
>> [*] https://lore.kernel.org/linux-mm/[email protected]/
>>
>> Signed-off-by: Joao Martins <[email protected]>
>> ---
>> include/linux/memory_hotplug.h | 5 ++++-
>> include/linux/mm.h | 3 ++-
>> mm/memory_hotplug.c | 3 ++-
>> mm/sparse-vmemmap.c | 3 ++-
>> mm/sparse.c | 24 +++++++++++++++---------
>> 5 files changed, 25 insertions(+), 13 deletions(-)
>>
>> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
>> index a7fd2c3ccb77..9b1bca80224d 100644
>> --- a/include/linux/memory_hotplug.h
>> +++ b/include/linux/memory_hotplug.h
>> @@ -14,6 +14,7 @@ struct mem_section;
>> struct memory_block;
>> struct resource;
>> struct vmem_altmap;
>> +struct dev_pagemap;
>>
>> #ifdef CONFIG_MEMORY_HOTPLUG
>> struct page *pfn_to_online_page(unsigned long pfn);
>> @@ -60,6 +61,7 @@ typedef int __bitwise mhp_t;
>> struct mhp_params {
>> struct vmem_altmap *altmap;
>> pgprot_t pgprot;
>> + struct dev_pagemap *pgmap;
>> };
>>
>> bool mhp_range_allowed(u64 start, u64 size, bool need_mapping);
>> @@ -333,7 +335,8 @@ extern void remove_pfn_range_from_zone(struct zone *zone,
>> 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);
>> + unsigned long nr_pages, struct vmem_altmap *altmap,
>> + struct dev_pagemap *pgmap);
>> extern void sparse_remove_section(struct mem_section *ms,
>> unsigned long pfn, unsigned long nr_pages,
>> unsigned long map_offset, struct vmem_altmap *altmap);
>> diff --git a/include/linux/mm.h b/include/linux/mm.h
>> index 7ca22e6e694a..f244a9219ce4 100644
>> --- a/include/linux/mm.h
>> +++ b/include/linux/mm.h
>> @@ -3083,7 +3083,8 @@ int vmemmap_remap_alloc(unsigned long start, unsigned
>> long end,
>>
>> void *sparse_buffer_alloc(unsigned long size);
>> struct page * __populate_section_memmap(unsigned long pfn,
>> - unsigned long nr_pages, int nid, struct vmem_altmap *altmap);
>> + unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
>> + struct dev_pagemap *pgmap);
>> pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
>> p4d_t *vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node);
>> pud_t *vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node);
>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>> index 8cb75b26ea4f..c728a8ff38ad 100644
>> --- a/mm/memory_hotplug.c
>> +++ b/mm/memory_hotplug.c
>> @@ -268,7 +268,8 @@ int __ref __add_pages(int nid, unsigned long pfn,
>> unsigned long nr_pages,
>> /* Select all remaining pages up to the next section
>> boundary */
>> cur_nr_pages = min(end_pfn - pfn,
>> SECTION_ALIGN_UP(pfn + 1) - pfn);
>> - err = sparse_add_section(nid, pfn, cur_nr_pages, altmap);
>> + err = sparse_add_section(nid, pfn, cur_nr_pages, altmap,
>> + params->pgmap);
>> if (err)
>> break;
>> cond_resched();
>> diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
>> index bdce883f9286..80d3ba30d345 100644
>> --- a/mm/sparse-vmemmap.c
>> +++ b/mm/sparse-vmemmap.c
>> @@ -603,7 +603,8 @@ int __meminit vmemmap_populate_basepages(unsigned long
>> start, unsigned long end,
>> }
>>
>> struct page * __meminit __populate_section_memmap(unsigned long pfn,
>> - unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
>> + unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
>> + struct dev_pagemap *pgmap)
>> {
>> unsigned long start = (unsigned long) pfn_to_page(pfn);
>> unsigned long end = start + nr_pages * sizeof(struct page);
>> diff --git a/mm/sparse.c b/mm/sparse.c
>> index 6326cdf36c4f..5310be6171f1 100644
>> --- a/mm/sparse.c
>> +++ b/mm/sparse.c
>> @@ -453,7 +453,8 @@ static unsigned long __init section_map_size(void)
>> }
>>
>> struct page __init *__populate_section_memmap(unsigned long pfn,
>> - unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
>> + unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
>> + struct dev_pagemap *pgmap)
>> {
>> unsigned long size = section_map_size();
>> struct page *map = sparse_buffer_alloc(size);
>> @@ -552,7 +553,7 @@ static void __init sparse_init_nid(int nid, unsigned
>> long pnum_begin,
>> break;
>>
>> map = __populate_section_memmap(pfn, PAGES_PER_SECTION,
>> - nid, NULL);
>> + nid, NULL, NULL);
>> if (!map) {
>> pr_err("%s: node[%d] memory map backing failed. Some
>> memory will not be available.",
>> __func__, nid);
>> @@ -657,9 +658,10 @@ void offline_mem_sections(unsigned long start_pfn,
>> unsigned long end_pfn)
>>
>> #ifdef CONFIG_SPARSEMEM_VMEMMAP
>> static struct page * __meminit populate_section_memmap(unsigned long pfn,
>> - unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
>> + unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
>> + struct dev_pagemap *pgmap)
>> {
>> - return __populate_section_memmap(pfn, nr_pages, nid, altmap);
>> + return __populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap);
>> }
>>
>> static void depopulate_section_memmap(unsigned long pfn, unsigned long
>> nr_pages,
>> @@ -728,7 +730,8 @@ static int fill_subsection_map(unsigned long pfn,
>> unsigned long nr_pages)
>> }
>> #else
>> struct page * __meminit populate_section_memmap(unsigned long pfn,
>> - unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
>> + unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
>> + struct dev_pagemap *pgmap)
>> {
>> return kvmalloc_node(array_size(sizeof(struct page),
>> PAGES_PER_SECTION), GFP_KERNEL, nid);
>> @@ -851,7 +854,8 @@ static void section_deactivate(unsigned long pfn,
>> unsigned long nr_pages,
>> }
>>
>> static struct page * __meminit section_activate(int nid, unsigned long pfn,
>> - unsigned long nr_pages, struct vmem_altmap *altmap)
>> + unsigned long nr_pages, struct vmem_altmap *altmap,
>> + struct dev_pagemap *pgmap)
>> {
>> struct mem_section *ms = __pfn_to_section(pfn);
>> struct mem_section_usage *usage = NULL;
>> @@ -883,7 +887,7 @@ static struct page * __meminit section_activate(int nid,
>> unsigned long pfn,
>> if (nr_pages < PAGES_PER_SECTION && early_section(ms))
>> return pfn_to_page(pfn);
>>
>> - memmap = populate_section_memmap(pfn, nr_pages, nid, altmap);
>> + memmap = populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap);
>> if (!memmap) {
>> section_deactivate(pfn, nr_pages, altmap);
>> return ERR_PTR(-ENOMEM);
>> @@ -898,6 +902,7 @@ static struct page * __meminit section_activate(int nid,
>> unsigned long pfn,
>> * @start_pfn: start pfn of the memory range
>> * @nr_pages: number of pfns to add in the section
>> * @altmap: device page map
>> + * @pgmap: device page map object that owns the section
>
> Since this patch is touching the kdoc, might as well fix it up
> properly for @altmap, and perhaps an alternate note for @pgmap:
>
> @altmap: alternate pfns to allocate the memmap backing store
> @pgmap: alternate compound page geometry for devmap mappings
>
Ah, indeed. I fixed it up and also added this to the commit message:
"While at it, fix the kdoc for @altmap for sparse_add_section()."
>
>> *
>> * This is only intended for hotplug.
>> *
>> @@ -911,7 +916,8 @@ static struct page * __meminit section_activate(int nid,
>> unsigned long pfn,
>> * * -ENOMEM - Out of memory.
>> */
>> int __meminit sparse_add_section(int nid, unsigned long start_pfn,
>> - unsigned long nr_pages, struct vmem_altmap *altmap)
>> + unsigned long nr_pages, struct vmem_altmap *altmap,
>> + struct dev_pagemap *pgmap)
>> {
>> unsigned long section_nr = pfn_to_section_nr(start_pfn);
>> struct mem_section *ms;
>> @@ -922,7 +928,7 @@ int __meminit sparse_add_section(int nid, unsigned long
>> start_pfn,
>> if (ret < 0)
>> return ret;
>>
>> - memmap = section_activate(nid, start_pfn, nr_pages, altmap);
>> + memmap = section_activate(nid, start_pfn, nr_pages, altmap, pgmap);
>> if (IS_ERR(memmap))
>> return PTR_ERR(memmap);
>>
>> --
>> 2.17.1
>>
