The patch titled
Subject: drivers/base/memory.c: don't store end_section_nr in memory blocks
has been added to the -mm tree. Its filename is
drivers-base-memoryc-dont-store-end_section_nr-in-memory-blocks.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/drivers-base-memoryc-dont-store-end_section_nr-in-memory-blocks.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/drivers-base-memoryc-dont-store-end_section_nr-in-memory-blocks.patch
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------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: drivers/base/memory.c: don't store end_section_nr in memory blocks
Each memory block spans the same amount of sections/pages/bytes. The size
is determined before the first memory block is created. No need to store
what we can easily calculate - and the calculations even look simpler now.
Michal brought up the idea of variable-sized memory blocks. However, if
we ever implement something like this, we will need an API compatibility
switch and reworks at various places (most code assumes a fixed memory
block size). So let's cleanup what we have right now.
While at it, fix the variable naming in register_mem_sect_under_node() -
we no longer talk about a single section.
Link: http://lkml.kernel.org/r/20190809110200.2746-1-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/base/memory.c | 1 -
drivers/base/node.c | 10 +++++-----
include/linux/memory.h | 1 -
mm/memory_hotplug.c | 2 +-
4 files changed, 6 insertions(+), 8 deletions(-)
--- a/drivers/base/memory.c~drivers-base-memoryc-dont-store-end_section_nr-in-memory-blocks
+++ a/drivers/base/memory.c
@@ -656,7 +656,6 @@ static int init_memory_block(struct memo
return -ENOMEM;
mem->start_section_nr = block_id * sections_per_block;
- mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
mem->state = state;
start_pfn = section_nr_to_pfn(mem->start_section_nr);
mem->phys_device = arch_get_memory_phys_device(start_pfn);
--- a/drivers/base/node.c~drivers-base-memoryc-dont-store-end_section_nr-in-memory-blocks
+++ a/drivers/base/node.c
@@ -756,13 +756,13 @@ static int __ref get_nid_for_pfn(unsigne
static int register_mem_sect_under_node(struct memory_block *mem_blk,
void *arg)
{
+ unsigned long memory_block_pfns = memory_block_size_bytes() / PAGE_SIZE;
+ unsigned long start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
+ unsigned long end_pfn = start_pfn + memory_block_pfns - 1;
int ret, nid = *(int *)arg;
- unsigned long pfn, sect_start_pfn, sect_end_pfn;
+ unsigned long pfn;
- sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
- sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr);
- sect_end_pfn += PAGES_PER_SECTION - 1;
- for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
+ for (pfn = start_pfn; pfn <= end_pfn; pfn++) {
int page_nid;
/*
--- a/include/linux/memory.h~drivers-base-memoryc-dont-store-end_section_nr-in-memory-blocks
+++ a/include/linux/memory.h
@@ -25,7 +25,6 @@
struct memory_block {
unsigned long start_section_nr;
- unsigned long end_section_nr;
unsigned long state; /* serialized by the dev->lock */
int section_count; /* serialized by mem_sysfs_mutex */
int online_type; /* for passing data to online routine */
--- a/mm/memory_hotplug.c~drivers-base-memoryc-dont-store-end_section_nr-in-memory-blocks
+++ a/mm/memory_hotplug.c
@@ -1648,7 +1648,7 @@ static int check_memblock_offlined_cb(st
phys_addr_t beginpa, endpa;
beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr));
- endpa = PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1;
+ endpa = beginpa + memory_block_size_bytes() - 1;
pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n",
&beginpa, &endpa);
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
mm-memory_hotplug-remove-move_pfn_range.patch
drivers-base-nodec-simplify-unregister_memory_block_under_nodes.patch
drivers-base-memoryc-fixup-documentation-of-removable-phys_index-block_size_bytes.patch
driver-base-memoryc-validate-memory-block-size-early.patch
resource-use-pfn_up-pfn_down-in-walk_system_ram_range.patch
mm-memory_hotplug-handle-unaligned-start-and-nr_pages-in-online_pages_blocks.patch
mm-memory_hotplug-simplify-online_pages_range.patch
mm-memory_hotplug-online_pages-cannot-be-0-in-online_pages.patch
drivers-base-memoryc-dont-store-end_section_nr-in-memory-blocks.patch
