[PATCH 1/2] makedumpfile: Add description of pages lost by ENOSPACE in IMPLEMENTATION

Atsushi Kumagai ats-kumagai at wm.jp.nec.com
Wed Jul 1 19:19:14 PDT 2015

>On 06/29/2015 04:33 PM, Atsushi Kumagai wrote:
>> Hello Zhou,
>>> Currently, there is no obvious description in IMPLEMENTATION for
>>> distinguishing the lost pages resulted by ENOSPACE errors or others.
>>> So, it is added.
>>> Signed-off-by: Zhou Wenjian<zhouwj-fnst at cn.fujitsu.com>
>>> ---
>>> IMPLEMENTATION |    2 ++
>>> 1 files changed, 2 insertions(+), 0 deletions(-)
>>> index 72df5d5..70a3f7c 100644
>>> @@ -240,6 +240,8 @@
>>>      The page header and page data are written in pairs. When writing page data
>>>      (pfn N+1), if ENOSPACE error happens, the page headers after N won't be
>>>      written either.
>>> +    When reading page from incomplete core, only the page lost by ENOSPACE errors
>>> +    has 0 in its corresponding page descriptor's member offset.
>> I'm not sure this is correct.
>> Could you point me where is the code which sets 0 to the page_desc->offset
>> of the lost page ?
>There is no code to set it. Since the data lost is filled with zero when it is read,
>the page_desc->offset will also be zero.
>And zero page has its own offset not equal 0. So we can distinguish them with their
>member offset.

Ah, you mean the behavior of crash ?
I think it would be better to describe that in more detail in order,
otherwise this additional description sounds sudden to me.

Atsushi Kumagai

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