lkml.org 
[lkml]   [2019]   [Aug]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] drivers/base/memory.c: Don't store end_section_nr in memory blocks
Date
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.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: David Hildenbrand <david@redhat.com>
---

v1 -> v2:
- Drop the macro for calculating the pfns per memory block

---
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(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 154d5d4a0779..cb80f2bdd7de 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -670,7 +670,6 @@ static int init_memory_block(struct memory_block **memory,
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);
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 840c95baa1d8..257449cf061f 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -756,13 +756,13 @@ static int __ref get_nid_for_pfn(unsigned long pfn)
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;

/*
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 02e633f3ede0..704215d7258a 100644
--- a/include/linux/memory.h
+++ b/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 */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 9a82e12bd0e7..db33a0ffcb1f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1650,7 +1650,7 @@ static int check_memblock_offlined_cb(struct memory_block *mem, void *arg)
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);

--
2.21.0
\
 
 \ /
  Last update: 2019-08-09 13:02    [W:0.029 / U:0.492 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site