于 2013年03月04日 23:24, Dave Anderson 写道:
>
>
> ----- Original Message -----
>> 于 2013年03月02日 05:20, Dave Anderson 写道:
>>>
>>>
>>> ----- Original Message -----
>>>> kmem -m is used for displaying information of all ksm pages or
>>>> some ksm pages for specified ksm stable tree node addresses
>>>> The information includes:
>>>> - physical address of ksm page,
>>>> - pid of tasks using this ksm page,
>>>> - counts of ksm page references for each task
>>>>
>>>> for example:
>>>> crash> kmem -m ffff8803573964c0
>>>> PID: 15864 16781
>>>> 793005000: 8713 5584
>>>>
>>>> ffff8803573964c0 is the address of ksm stable tree node.
>>>> task 15864 has 8713 virtual pages mapping the page with address 793005000.
>>>> task 16781 has 5584 virtual pages mapping the page with address 793005000.
>>>>
>>>> P.S.
>>>> This patch is based on the patch from
>>>> Qiao(qiaonuohan@xxxxxxxxxxxxxx)
>>>> 0001-make-rbtree-manipulation-functions-global.patch
>>>> Because this patch also uses rb_tree operations.
>>>
>>> I'll get to this patch after I get Qiao's patch straightened out and
>>> checked in.
>>>
>>> But a couple quick questions...
>>>
>>> What does "kmem -m" alone look like? Your help page example only
>>> shows the command passing a "ksm stable tree node address".
>>
>> 'kmem -m' will display all the ksm pages.
>
> I meant could you show an example of "kmem -m"...
>
>>
>>> How would a user know what one of those addresses would be?
>>
>> From the structure "rmap_item" ? it has a member "head" that points
>> to a ksm stable tree node.
>
> So does "kmem -m" show a list of those addresses?
oops...I misunderstood your question. The display is like:
crash> kmem -m
PID: 3622 3512
867605000: 187 7671
PID: 3622 3512
465837000: 1 1
PID: 3622 3512
465803000: 1 1
PID: 3512
4643d0000: 2
PID: 3512
81bddc000: 2
PID: 3512
841c36000: 2
PID: 3512
4653e5000: 2
PID: 3512
842bc1000: 3
PID: 3512
455b4b000: 11
PID: 3512
453842000: 3
......
All ksm pages are displayed. For every ksm page, for example
a ksm page with physical address 867605000, has two tasks
reference it: 3622 and 3512. 3622 has 187 virtual mappings
into the ksm page and 3512 has 7671 virtual mappings into
the ksm page.
PID: 3622 3512
867605000: 187 7671
>
>>>
>>> And for "kmem -m <address>", what if there are dozens of PIDs that
>>> are mapping the same physical address? Regardless of the size of
>>> the display window, eventually it would get messy if it extends to
>>> more than one line. I try to avoid having commands extend beyond
>>> 80 columns if at all possible.
>>>
>>
>> Hmm. If there are quite many PIDs, can the output be like below?
>>
>> PID: 15864 16781 16782 16783
>> 793005000: 8713 5584 23 23
>> 12222 13333 14444 15555
>> 232 232 334 456
>> ...
>
> Well, that's not much clearer -- it's difficult to tell whether the
> numbers are PIDs or counts.
Do you have any suggestions...
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