diff mbox

[v2,02/23] mm/memblock: debug: don't free reserved array if !ARCH_DISCARD_MEMBLOCK

Message ID 1386037658-3161-3-git-send-email-santosh.shilimkar@ti.com (mailing list archive)
State New, archived
Headers show

Commit Message

Santosh Shilimkar Dec. 3, 2013, 2:27 a.m. UTC 
From: Grygorii Strashko <grygorii.strashko@ti.com>

Now the Nobootmem allocator will always try to free memory allocated for
reserved memory regions (free_low_memory_core_early()) without taking
into to account current memblock debugging configuration
(CONFIG_ARCH_DISCARD_MEMBLOCK and CONFIG_DEBUG_FS state).
As result if:
 - CONFIG_DEBUG_FS defined
 - CONFIG_ARCH_DISCARD_MEMBLOCK not defined;
-  reserved memory regions array have been resized during boot

then:
- memory allocated for reserved memory regions array will be freed to
buddy allocator;
- debug_fs entry "sys/kernel/debug/memblock/reserved" will show garbage
instead of state of memory reservations. like:
   0: 0x98393bc0..0x9a393bbf
   1: 0xff120000..0xff11ffff
   2: 0x00000000..0xffffffff

Hence, do not free memory allocated for reserved memory regions if
defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK).

Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
---
 mm/memblock.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Tejun Heo Dec. 3, 2013, 10:52 p.m. UTC | #1 
On Mon, Dec 02, 2013 at 09:27:17PM -0500, Santosh Shilimkar wrote:
...
> Cc: Yinghai Lu <yinghai@kernel.org>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

Reviewed-by: Tejun Heo <tj@kernel.org>

> +	/*
> +	 * Don't allow Nobootmem allocator to free reserved memory regions

Extreme nitpick: why the capitalization of "Nobootmem"?

Thanks.
Santosh Shilimkar Dec. 4, 2013, 2:58 p.m. UTC | #2 
On Tuesday 03 December 2013 05:52 PM, Tejun Heo wrote:
> On Mon, Dec 02, 2013 at 09:27:17PM -0500, Santosh Shilimkar wrote:
> ...
>> Cc: Yinghai Lu <yinghai@kernel.org>
>> Cc: Tejun Heo <tj@kernel.org>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
> 
> Reviewed-by: Tejun Heo <tj@kernel.org>
> 
>> +	/*
>> +	 * Don't allow Nobootmem allocator to free reserved memory regions
> 
> Extreme nitpick: why the capitalization of "Nobootmem"?
> 
Will fix that
diff mbox

Patch

diff --git a/mm/memblock.c b/mm/memblock.c
index aab5669..53da534 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -265,6 +265,19 @@  phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info(
 	if (memblock.reserved.regions == memblock_reserved_init_regions)
 		return 0;
 
+	/*
+	 * Don't allow Nobootmem allocator to free reserved memory regions
+	 * array if
+	 *  - CONFIG_DEBUG_FS is enabled;
+	 *  - CONFIG_ARCH_DISCARD_MEMBLOCK is not enabled;
+	 *  - reserved memory regions array have been resized during boot.
+	 * Otherwise debug_fs entry "sys/kernel/debug/memblock/reserved"
+	 * will show garbage instead of state of memory reservations.
+	 */
+	if (IS_ENABLED(CONFIG_DEBUG_FS) &&
+	    !IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK))
+		return 0;
+
 	*addr = __pa(memblock.reserved.regions);
 
 	return PAGE_ALIGN(sizeof(struct memblock_region) *