----- Original Message -----
>
>
> ----- Original Message -----
> > Hi Dave,
> >
> > I recently looked into a linux 4.0 dump where the "ps" command prints "??"
> > for the state field of several tasks:
> >
> > crash> ps
> > 741 660 1 7b408000 ?? 0.0 2152 2592 chcpu
> > 748 2 24 20c284f00 IN 0.0 0 0
> > [migration/24]
> > 752 2 22 20b1ccf00 ?? 0.0 0 0
> > [migration/25]
> >
> > Looking at the "task_struct->state" I get the following:
> >
> > crash> task_struct 7b408000 | grep state
> > state = 0x100,
> > crash> task_struct 20b1ccf00 | grep state
> > state = 0x200
> >
> > Looking into include/linux/sched.h states are defined as follows:
> >
> > #define TASK_RUNNING 0
> > ...
> > #define TASK_WAKING 256
> > #define TASK_PARKED 512
> >
> > When I issue "help -t" I get the following:
> >
> > RUNNING: 0 (0x0)
> > INTERRUPTIBLE: 1 (0x1)
> > UNINTERRUPTIBLE: 2 (0x2)
> > STOPPED: 4 (0x4)
> > TRACING_STOPPED: 8 (0x8)
> > ZOMBIE: 32 (0x20)
> > DEAD: 16 and 32 (0x10 and 0x20)
> > WAKEKILL: 64 (0x40)
> > WAKING: 128 (0x80) <- Should be 256?
> >
> > I have not digged deeper, but at least wanted to report this issue.
> > Perhaps you see the problem at once.
> >
> > Michael
> >
> >
>
> I see it now. The states are gathered from the kernel's task_state_array[].
> So on a 3.9-based kernel, for example, it's this:
>
> crash> p task_state_array
> task_state_array = $1 =
> {0xffffffff81a01959 "R (running)", 0xffffffff81a01965 "S (sleeping)",
> 0xffffffff81a01972 "D (disk sleep)", 0xffffffff81a01981 "T (stopped)",
> 0xffffffff81a0198d "t (tracing stop)", 0xffffffff81a0199e "Z (zombie)",
> 0xffffffff81a019a9 "X (dead)", 0xffffffff81a019b2 "x (dead)",
> 0xffffffff81a019bb "K (wakekill)", 0xffffffff81a019c8 "W (waking)",
> 0xffffffff81a019d3 "P (parked)"}
> crash>
>
> And for example, here's the 3.10 kernel's declaration:
>
> /*
> * The task state array is a strange "bitmap" of
> * reasons to sleep. Thus "running" is zero, and
> * you can test for combinations of others with
> * simple bit tests.
> */
> static const char * const task_state_array[] = {
> "R (running)", /* 0 */
> "S (sleeping)", /* 1 */
> "D (disk sleep)", /* 2 */
> "T (stopped)", /* 4 */
> "t (tracing stop)", /* 8 */
> "Z (zombie)", /* 16 */
> "X (dead)", /* 32 */
> "x (dead)", /* 64 */
> "K (wakekill)", /* 128 */
> "W (waking)", /* 256 */
> "P (parked)", /* 512 */
> };
>
> where on a 4.0.5 kernel, the wakekill, waking and parked fields no longer
> exist in the array:
>
> crash> p task_state_array
> task_state_array = $1 =
> {0xffffffff81a73b42 "R (running)", 0xffffffff81a73b4e "S (sleeping)",
> 0xffffffff81a73b5b "D (disk sleep)", 0xffffffff81a73b6a "T (stopped)",
> 0xffffffff81a73b76 "t (tracing stop)", 0xffffffff81a73b87 "X (dead)",
> 0xffffffff81a73b90 "Z (zombie)"}
> crash>
>
> This is the upstream kernel declaration:
>
> static const char * const task_state_array[] = {
> "R (running)", /* 0 */
> "S (sleeping)", /* 1 */
> "D (disk sleep)", /* 2 */
> "T (stopped)", /* 4 */
> "t (tracing stop)", /* 8 */
> "X (dead)", /* 16 */
> "Z (zombie)", /* 32 */
> };
>
> Not sure where the wakekill, waking, and parked went yet though...
>
> Dave
Looks like I should probably change the scheme to gather the state information
from the stat_nam[] string instead:
#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWP"
static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
Thanks for the heads-up.
Dave
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