On 2023/07/31 17:18, lijiang wrote:
> Thank you for the comments, Kazu.
>
> On Mon, Jul 31, 2023 at 10:08 AM HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@xxxxxxx>
> wrote:
>
>> On 2023/07/28 20:15, Lianbo Jiang wrote:
>>> Currently, the "foreach DE ps -m" command may display "DE" as well as
>>> "ZO" state tasks as below:
>>>
>>> crash> foreach DE ps -m
>>> ...
>>> [0 00:00:00.040] [ZO] PID: 11458 TASK: ffff91c75680d280 CPU: 7
>> COMMAND: "ora_w01o_p01mci"
>>> [0 00:00:00.044] [ZO] PID: 49118 TASK: ffff91c7bf3e8000 CPU: 19
>> COMMAND: "oracle_49118_p0"
>>> [0 00:00:00.050] [ZO] PID: 28748 TASK: ffff91a7cbde3180 CPU: 2
>> COMMAND: "ora_imr0_p01sci"
>>> [0 00:00:00.050] [DE] PID: 28405 TASK: ffff91a7c8eb0000 CPU: 27
>> COMMAND: "ora_vktm_p01sci"
>>> [0 00:00:00.051] [ZO] PID: 31716 TASK: ffff91a7f7192100 CPU: 6
>> COMMAND: "ora_p001_p01sci"
>>> ...
>>
>> Could you elaborate on why this happens?
>>
>>
> When the "DE" identifier is specified in the foreach command, it needs to
> skip the non-"DE" tasks. Currently, crash doesn't deal with this case, only
> handles some cases, such as "_RUNNING_", "_UNINTERRUPTIBLE_", "_NOLOAD_",
> etc. So most tasks will be displayed directly.
>
> I'm concerned about the difference of the conditions between printing
>> the "DE" state in task_state_string() and printing a "DE" task in the
>> foreach function in your patch:
>>
>> char *
>> task_state_string(ulong task, char *buf, int verbose)
>> {
>> ...
>> if ((state & _DEAD_) && !set) {
>> sprintf(buf, "DE");
>> valid++;
>> set++;
>> }
>>
>> On the other hand, the following means that "state == _DEAD_" is the
>> "DE" state, not "state & _DEAD". So I'm wondering if "foreach DE"
>> command might drop some "DE" tasks with your patch?
>>
>>
> The condition "state & _DEAD" can not filter out the tasks with a state
> value of 0x50(0x10 + 0x40). It indicates that the "ZO" state tasks will be
> always displayed, when the "DE" identifier is specified.
>
> I just did the debug on it, let me share an example:
>
> crash> foreach DE ps -m
> ...
> foreach: state: 0x60, task_state: 0x50
> [0 00:00:00.040] [ZO] PID: 11458 TASK: ffff91c75680d280 CPU: 7
> COMMAND: "ora_w01o_p01mci"
> foreach: state: 0x60, task_state: 0x50
> [0 00:00:00.044] [ZO] PID: 49118 TASK: ffff91c7bf3e8000 CPU: 19
> COMMAND: "oracle_49118_p0"
> foreach: state: 0x60, task_state: 0x50
> [0 00:00:00.050] [ZO] PID: 28748 TASK: ffff91a7cbde3180 CPU: 2
> COMMAND: "ora_imr0_p01sci"
> foreach: state: 0x60, task_state: 0x60
> [0 00:00:00.050] [DE] PID: 28405 TASK: ffff91a7c8eb0000 CPU: 27
> COMMAND: "ora_vktm_p01sci"
> foreach: state: 0x60, task_state: 0x50
> [0 00:00:00.051] [ZO] PID: 31716 TASK: ffff91a7f7192100 CPU: 6
> COMMAND: "ora_p001_p01sci"
> ...
>
> The DEAD state value is 0x60(0x20 + 0x40), the actual task state value is
> 0x50(0x10 + 0x40), and the ZOMBIE state value is 0x10, regardless of the
> "task_state(task) & _DEAD_" or "task_state(task) & _ZOMBIE_", the result is
> always true. So the condition "state & _DEAD" can not handle this case.
OK, thanks for the explanation.
So the following condition cannot filter out the "ZO" tasks that have
EXIT_ZOMBIE(0x10) and TASK_DEAD(0x40) with _DEAD_(0x60).
} else if (!(task_state(tc->task) & fd->state))
continue;
What I was concerned about is that
> + if (task_state(tc->task) != _DEAD_)
> + continue;
this condition may skip "DE" tasks that have only either EXIT_DEAD(0x20)
or TASK_DEAD(0x40). If there can't be such tasks at any timing, then no
problem though.
Anyway, if you adopt that idea, my concern will be solved.
Thanks,
Kazu
>
> And also the actual task has a "DE" state value of 0x60.
> ...
> foreach: state: 0x60, task_state: 0x60
> [0 00:00:00.050] [DE] PID: 28405 TASK: ffff91a7c8eb0000 CPU: 27
> COMMAND: "ora_vktm_p01sci"
> ...
>
> crash> help -t
> ...
> RUNNING: 0 (0x0)
> INTERRUPTIBLE: 1 (0x1)
> UNINTERRUPTIBLE: 2 (0x2)
> STOPPED: 4 (0x4)
> TRACING_STOPPED: 8 (0x8)
> ZOMBIE: 16 (0x10)
> DEAD: 32 and 64 (0x20 and 0x40)
> WAKEKILL: 128 (0x80)
> WAKING: 256 (0x100)
> PARKED: 512 (0x200)
> crash>
>
> Thanks.
> Lianbo
--
Crash-utility mailing list
Crash-utility@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/crash-utility
Contribution Guidelines: https://github.com/crash-utility/crash/wiki
