Re: [PATCH v2 5/5] page_alloc: Bootmem limit with movablecore_map

From: Tang Chen
Date: Mon Nov 26 2012 - 08:15:55 EST

On 11/26/2012 08:40 PM, wujianguo wrote:
Hi Tang,
I tested this patchset in x86_64, and I found that this patch didn't
work as expected.
For example, if node2's memory pfn range is [0x680000-0x980000),
I boot kernel with movablecore_map=4G@0x680000000, all memory in node2 will be
in ZONE_MOVABLE, but bootmem still can be allocated from [0x780000000-0x980000000),
that means bootmem *is allocated* from ZONE_MOVABLE. This because movablecore_map
only contains [0x680000000-0x780000000). I think we can fixup movablecore_map, how
about this:

Hi Wu,

That is really a problem. And, before numa memory got initialized,
memblock subsystem would be used to allocate memory. I didn't find any
approach that could fully address it when I making the patches. There
always be risk that memblock allocates memory on ZONE_MOVABLE. I think
we can only do our best to prevent it from happening.

Your patch is very helpful. And after a shot look at the code, it seems
that acpi_numa_memory_affinity_init() is an architecture dependent
function. Could we do this somewhere which is not depending on the
architecture ?

Thanks. :)


Signed-off-by: Jianguo Wu<wujianguo@xxxxxxxxxx>
Signed-off-by: Jiang Liu<jiang.liu@xxxxxxxxxx>
---
arch/x86/mm/srat.c | 15 +++++++++++++++
include/linux/mm.h | 3 +++
mm/page_alloc.c | 2 +-
3 files changed, 19 insertions(+), 1 deletions(-)

diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
index 4ddf497..f1aac08 100644
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -147,6 +147,8 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
{
u64 start, end;
int node, pxm;
+ int i;
+ unsigned long start_pfn, end_pfn;

if (srat_disabled())
return -1;
@@ -181,6 +183,19 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
printk(KERN_INFO "SRAT: Node %u PXM %u [mem %#010Lx-%#010Lx]\n",
node, pxm,
(unsigned long long) start, (unsigned long long) end - 1);
+
+ start_pfn = PFN_DOWN(start);
+ end_pfn = PFN_UP(end);
+ for (i = 0; i< movablecore_map.nr_map; i++) {
+ if (end_pfn<= movablecore_map.map[i].start)
+ break;
+
+ if (movablecore_map.map[i].end< end_pfn) {
+ insert_movablecore_map(movablecore_map.map[i].end,
+ end_pfn);
+ }
+ }
+
return 0;
}

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5a65251..7a23403 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1356,6 +1356,9 @@ extern int __meminit __early_pfn_to_nid(unsigned long pfn);
#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
#endif

+extern void insert_movablecore_map(unsigned long start_pfn,
+ unsigned long end_pfn);
+
extern void set_dma_reserve(unsigned long new_dma_reserve);
extern void memmap_init_zone(unsigned long, int, unsigned long,
unsigned long, enum memmap_context);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 544c829..e6b5090 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5089,7 +5089,7 @@ early_param("movablecore", cmdline_parse_movablecore);
* This function will also merge the overlapped ranges, and sort the array
* by start_pfn in monotonic increasing order.
*/
-static void __init insert_movablecore_map(unsigned long start_pfn,
+void __init insert_movablecore_map(unsigned long start_pfn,
unsigned long end_pfn)
{
int pos, overlap;
-- 1.7.6.1
.

Thanks,
Jianguo Wu

On 2012-11-23 18:44, Tang Chen wrote:
This patch make sure bootmem will not allocate memory from areas that
may be ZONE_MOVABLE. The map info is from movablecore_map boot option.

Signed-off-by: Tang Chen<tangchen@xxxxxxxxxxxxxx>
Signed-off-by: Lai Jiangshan<laijs@xxxxxxxxxxxxxx>
Reviewed-by: Wen Congyang<wency@xxxxxxxxxxxxxx>
Tested-by: Lin Feng<linfeng@xxxxxxxxxxxxxx>
---
include/linux/memblock.h | 1 +
mm/memblock.c | 15 ++++++++++++++-
2 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index d452ee1..6e25597 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -42,6 +42,7 @@ struct memblock {

extern struct memblock memblock;
extern int memblock_debug;
+extern struct movablecore_map movablecore_map;

#define memblock_dbg(fmt, ...) \
if (memblock_debug) printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
diff --git a/mm/memblock.c b/mm/memblock.c
index 6259055..33b3b4d 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -101,6 +101,7 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
{
phys_addr_t this_start, this_end, cand;
u64 i;
+ int curr = movablecore_map.nr_map - 1;

/* pump up @end */
if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
@@ -114,13 +115,25 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
this_start = clamp(this_start, start, end);
this_end = clamp(this_end, start, end);

- if (this_end< size)
+restart:
+ if (this_end<= this_start || this_end< size)
continue;

+ for (; curr>= 0; curr--) {
+ if (movablecore_map.map[curr].start< this_end)
+ break;
+ }
+
cand = round_down(this_end - size, align);
+ if (curr>= 0&& cand< movablecore_map.map[curr].end) {
+ this_end = movablecore_map.map[curr].start;
+ goto restart;
+ }
+
if (cand>= this_start)
return cand;
}
+
return 0;
}





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