Hi,
I am using custom 460ex board with kernel version 2.6.30.
I noticed that page_alloc() is returning a page whose memory
is already allocated by lmb_alloc() while unflattening the device
tree. As per my knowledge the memory allocated by lmb_alloc()
should be reserved till the end, right?
Some more explanation of what I observed:
unflatten_device_tree() allocates memory, which will be used
for "struct node" objects in the device tree. I obtained base
address of allocated memory in "unsigned long base_mem"
Now I executed the following code after the kernel booted properly.
---------------------------------------------------------------
extern unsigned long mem; // lmb_alloc() memory
struct page *test_page = virt_to_page(mem);
struct page *new_page = NULL;
while(1)
{
new_page = NULL;
new_page = alloc_page(GFP_KERNEL);
if(!new_page)
{
printk("Allocation failed\n");
while(1);
}
if(test_page == new_page)
{
printk("Memory already allocated by lmb_alloc\n");
while(1);
}
}
---------------------------------------------------------------
After many page allocations, I always hit the condition (test_page == new_page).
Am I doing anything wrong here?
Has anybody faced this kind of problem before?
I also noticed that lmb_dump_all() shows 2 regions overlapping (last two):
LMB configuration:
rmo_size = 0x30000000
memory.size = 0x30000000
memory.cnt = 0x1
memory[0x0] 0x0000000000000000 - 0x000000002fffffff, 0x30000000 bytes
reserved.cnt = 0x6
reserved[0x0] 0x0000000000000000 - 0x00000000006bffff, 0x6c0000 bytes
reserved[0x1] 0x0000000000ffa000 - 0x0000000000ffcfff, 0x3000 bytes
reserved[0x2] 0x000000002fdd0000 - 0x000000002fddffff, 0x10000 bytes
reserved[0x3] 0x000000002fde4000 - 0x000000002fde9fff, 0x6000 bytes
reserved[0x4] 0x000000002fdeb060 - 0x000000002ffff768, 0x214709 bytes
reserved[0x5] 0x000000002fdee000 - 0x000000002ffff769, 0x21176a bytes
Thanks,
Prashant
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
