[PATCH 1/2] makedumpfile: Delete useless codes

[Atsushi Kumagai]

>On 06/29/2015 04:34 PM, Atsushi Kumagai wrote:
>>> free_bitmap_buffer() in create_dump_bitmap() includes free_bitmap2_buffer().
>>> So delete free_bitmap2_buffer().
>>
>> I thought that calling free_bitmap_buffer() at the end of create_dump_bitmap()
>> is wrong, actually I fixed that in the devel branch like below:
>>
>>    int
>>    create_dump_bitmap(void)
>>    {
>>    ...
>>            /* Should keep the buffer in the 1-cycle case. */
>>            if (info->flag_cyclic)
>>                    free_bitmap_buffer();
>>
>>            return ret;
>>    }
>>
>> The reason why we free the 2nd bitmap buffer once here is to reduce the
>> memory consumption for the multi-cycle case in the kdump-compressed path,
>> otherwise the bitmap buffers should be kept during execution.
>>
>
>I knew that, but I have one question.
>Why it is needed in kdump-compressed but not in elf?
>I noticed that in kdump-compressed, 2nd bitmap would also be re-prepared.

The elf format doesn't include the 1st bitmap and is_dumpable() depends on
the 2nd bitmap, so there is no meaning to prepare the 1st bitmap buffer in elf.
OTOH, the kdump-compressed format include both 1st and 2nd bitmap, it's
necessary to prepare two buffers individually.


Thanks
Atsushi Kumagai

>> If the buffers are kept as expected, there is no need to re-prepare the
>> 2nd bitmap buffer as [PATCH 2/2].
>>
>> However, thanks to you, I notice that the current devel code still
>> free the 2nd bitmap buffer in the ELF path even though it's necessary.
>> So I'll fix it.
>>
>>
>> Thanks
>> Atsushi Kumagai
>>
>>> Signed-off-by: Zhou wenjian<zhouwj-fnst at cn.fujitsu.com>
>>> ---
>>> makedumpfile.c |    3 ---
>>> 1 files changed, 0 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/makedumpfile.c b/makedumpfile.c
>>> index cc71f20..7f2949c 100644
>>> --- a/makedumpfile.c
>>> +++ b/makedumpfile.c
>>> @@ -5933,9 +5933,6 @@ create_dump_bitmap(void)
>>>
>>> 		info->num_dumpable = get_num_dumpable_cyclic();
>>>
>>> -		if (!info->flag_elf_dumpfile)
>>> -			free_bitmap2_buffer();
>>> -
>>> 	} else {
>>> 		struct cycle cycle = {0};
>>> 		first_cycle(0, info->max_mapnr,&cycle);
>>> --
>>> 1.7.1
>>>
>>>
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>
>
>--
>Thanks
>Zhou Wenjian