Re: [PATCH 1/2] makedumpfile: Delete useless codes

["\"Zhou, Wenjian/周文剑\"" <zhouwj-fnst@cn.fujitsu.com>]

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.

> 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@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

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