3:18 a.m.
Thank you for the comments, Kazu.
On Mon, Jul 31, 2023 at 10:08 AM HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com>
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.
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
+ if (task_state(tc->task) != _DEAD_)
> + continue;
Thanks,
Kazu
>
> That is not expected behavior, the "foreach" command needs to handle
> such cases. Let's add a check to determine if the task state identifier
> is specified and the task state identifier is equal to the "DE", so that
> it can filter out the non-"DE" state tasks.
>
> With the patch:
> crash> foreach DE ps -m
> [0 00:00:00.050] [DE] PID: 28405 TASK: ffff91a7c8eb0000 CPU: 27
COMMAND: "ora_vktm_p01sci"
> crash>
>
> Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com>
> ---
> task.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/task.c b/task.c
> index b9076da35565..4f40c396b195 100644
> --- a/task.c
> +++ b/task.c
> @@ -7043,6 +7043,9 @@ foreach(struct foreach_data *fd)
> if (fd->state == _RUNNING_) {
> if (task_state(tc->task) != _RUNNING_)
> continue;
> + } else if (fd->state == _DEAD_) {
> + if (task_state(tc->task) != _DEAD_)
> + continue;
> } else if (fd->state & _UNINTERRUPTIBLE_) {
> if (!(task_state(tc->task) &
_UNINTERRUPTIBLE_))
> continue;