[CRIU] About thread names after restore

[Pavel Emelyanov]

On 08/25/2015 02:02 PM, Artem Kuzmitskiy wrote:
> 
> 
> 2015-08-25 12:37 GMT+03:00 Pavel Emelyanov <xemul at parallels.com <mailto:xemul at parallels.com>>:
> 
>     On 08/25/2015 10:50 AM, Artem Kuzmitskiy wrote:
>     >
>     >
>     > 2015-08-21 20:57 GMT+03:00 Pavel Emelyanov <xemul at parallels.com <mailto:xemul at parallels.com> <mailto:xemul at parallels.com <mailto:xemul at parallels.com>>>:
>     >
>     >     On 08/18/2015 06:32 PM, Artem Kuzmitskiy wrote:
>     >     > Hi all,
>     >     >
>     >     > I'm not sure what it's important, but I found that thread names (if were
>     >     > assigned using prctl\pthread_setname) not restored. Is it bug or not?
>     >
>     >     Well, if criu doesn't support something, then it's definitely a bug, but
>     >     we don't call it such. Not-yet-implemented-feature.
>     >
>     > Ок.
>     >
>     >     > Steps for reproduce:
>     >     > 1. Start thread and assign name.
>     >     >     pthread_create(&thread, NULL, do_nothing, NULL);
>     >     >     pthread_setname_np(thread, "NOTHING_THREAD");
>     >     > 2. Check name using procfs
>     >     > $ cat /proc/12857/task/12858/stat
>     >     > 12858 (NOTHING_THREAD) .....
>     >     > 3. Dump process with this thread
>     >     > 4. Restore process
>     >     > 5. Check again
>     >     >  cat /proc/12857/task/12858/stat
>     >     > 12858 (socketpair) .....
>     >     >
>     >     > P.S. In pstree.img not include the thread names now, only tid.
>     >
>     >     Yup. Patch for this is warmly welcome.
>     >
>     > I feel that this is part of parasite code?
> 
>     For restore -- yes, threads are restored in parasite, so name restore should also go there.
> 
> On first look, these data may be inserted to pstree.img in threads section Am I right?
> 
> -----------
> # ../../../crit decode -i pstree.img
> {"magic": "PSTREE", "entries": [{"pgid": 12857, "threads": [12857, 12858], "ppid": 0, "pid": 12857, "sid": 12857}]}
> -----------

No, task's names sit in core.img: core_entry.tc.comm, so thread name should go to
the same image. Each thread has it's own core.img.

-- Pavel