[PATCH] crash_core: export vmemmap when CONFIG_SPARSEMEM_VMEMMAP is enabled

[Shijie Huang]

在 2023/11/27 10:51, Baoquan He 写道:
> Hi,
>
> On 11/27/23 at 10:07am, Huang Shijie wrote:
>> In memory_model.h, if CONFIG_SPARSEMEM_VMEMMAP is configed,
>> kernel will use vmemmap to do the __pfn_to_page/page_to_pfn,
>> and kernel will not use the "classic sparse" to do the
>> __pfn_to_page/page_to_pfn.
>>
>> So export the vmemmap when CONFIG_SPARSEMEM_VMEMMAP is configed.
>> This makes the user applications (crash, etc) get faster
>> pfn_to_page/page_to_pfn operations too.
> Are there Crash or makedupfile patches posted yet to make use of this?

I have patches for Crash to use the 'vmemmap', but after this patch is 
merged, I will send it out.

(I think Kazu will not merge a crash patch which depends on a kernel 
patch which is not merged.)


Thanks

Huang Shijie


>> Signed-off-by: Huang Shijie <shijie at os.amperecomputing.com>
>> ---
>>   kernel/crash_core.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
>> index efe87d501c8c..9653c4177191 100644
>> --- a/kernel/crash_core.c
>> +++ b/kernel/crash_core.c
>> @@ -765,6 +765,9 @@ static int __init crash_save_vmcoreinfo_init(void)
>>   	VMCOREINFO_SYMBOL(mem_map);
>>   	VMCOREINFO_SYMBOL(contig_page_data);
>>   #endif
>> +#ifdef CONFIG_SPARSEMEM_VMEMMAP
>> +	VMCOREINFO_SYMBOL_ARRAY(vmemmap);
>> +#endif
>>   #ifdef CONFIG_SPARSEMEM
>>   	VMCOREINFO_SYMBOL_ARRAY(mem_section);
>>   	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
>> -- 
>> 2.40.1
>>