>> I think the Michael's first idea below is better since it implements
>> is_real_addr() only for --mem-usage as a common function for all
>> architectures, it's explicit design.
>>
>> >@@ -854,7 +854,7 @@ int get_kcore_dump_loads(void)
>> >
>> > for (i = 0; i < num_pt_loads; ++i) {
>> > struct pt_load_segment *p = &pt_loads[i];
>> >- if (is_vmalloc_addr(p->virt_start))
>> >+ if (!is_real_addr(p->virt_start))
>> > continue;
>> > loads++;
>> > }
>>
>> However, this code will not work since the argument of is_real_addr()
>> must be physical address. Even unluckily, /proc/kcore's PT_LOAD looks
>> useless for VtoP converting because PhysAddr is always 0:
>>
>> Program Headers:
>> Type Offset VirtAddr PhysAddr
>> FileSiz MemSiz Flags Align
>> NOTE 0x00000000000002a8 0x0000000000000000 0x0000000000000000
>> 0x0000000000000a84 0x0000000000000000 0
>> LOAD 0x00007fffff601000 0xffffffffff600000 0x0000000000000000
>> 0x0000000000001000 0x0000000000001000 RWE 1000
>> LOAD 0x00007fff81001000 0xffffffff81000000 0x0000000000000000
>> 0x0000000000a1b000 0x0000000000a1b000 RWE 1000
>> LOAD 0x0000490000001000 0xffffc90000000000 0x0000000000000000
>> 0x00001fffffffffff 0x00001fffffffffff RWE 1000
>> LOAD 0x00007fffa0001000 0xffffffffa0000000 0x0000000000000000
>> 0x000000005f000000 0x000000005f000000 RWE 1000
>> ...
>>
>>
>> So the way using /proc/iomem seems inappropriate, we have to consider other
>> approaches (but I still don't have any good ideas...)
>
>Hello Atsushi,
>
>Hmmm ok, sure. For x86 using /proc/iomem does not work because there is no 1:1
>mapping for the kernel address space. The kernel/real memory is mapped somewhere
>at the end, right?
Exactly.
>For s390 we have a 1:1 mapping for the kernel physical memory that starts with
>zero. Therefore IMHO we could use /proc/iomem. For example, on my s390x system
>with 1GB memory and 256MB crashkernel:
>
>$ cat /proc/iomem
>00000000-2fffffff : System RAM
> 00000000-007ddd4b : Kernel code
> 007ddd4c-00bfcc5f : Kernel data
> 00e18000-01c28b1f : Kernel bss
>30000000-3fffffff : Crash kernel
>
>$ objdump -h /proc/kcore
>...
> Type Offset VirtAddr PhysAddr
> FileSiz MemSiz Flags Align
> NOTE 0x0000000000000158 0x0000000000000000 0x0000000000000000
> 0x00000000000027fc 0x0000000000000000 0
> LOAD 0x000003e080003000 0x000003e080000000 0x0000000000000000
> 0x0000001f00000000 0x0000001f00000000 RWE 1000
> LOAD 0x000003ff80003000 0x000003ff80000000 0x0000000000000000
> 0x0000000080000000 0x0000000080000000 RWE 1000
> LOAD 0x0000000000003000 0x0000000000000000 0x0000000000000000
> 0x0000000030000000 0x0000000030000000 RWE 1000
> LOAD 0x000003d100003000 0x000003d100000000 0x0000000000000000
> 0x0000000000c00000 0x0000000000c00000 RWE 1000
>
>So in that case every /proc/kcore load that is below 0x30000000 must
>be real memory.
>
>Michael
I understand why your patch works on s390x, so how about this way ?
1. Define "is_phys_addr()" for --mem-usage.
2. Implement is_phys_addr() using is_iomem_phys_addr() for s390x
while x86_64 uses is_vmalloc_addr_x86_64().
3. Use is_phys_addr() instead of is_vmalloc_addr() in get_kcore_dump_loads().
Thanks,
Atsushi Kumagai
