Re: [PATCH 2.6.13.1] Patch for invisible threads
From: Sripathi Kodi
Date: Tue Sep 13 2005 - 08:12:49 EST
Andrew,
Andrew Morton wrote:
Sripathi Kodi <sripathik@xxxxxxxxxx> wrote:
Hi,
When the main thread of a multi-threaded program calls 'pthread_exit' before
other threads have exited, it results in the other threads becoming
'invisible' to commands like 'ps'.
This stuff is subtle. Let me cc some subtle people.
Signed-off-by: Sripathi Kodi <sripathik@xxxxxxxxxx>
--- linux-2.6.13.1/kernel/exit.c 2005-09-12 02:46:26.000000000 -0500
+++ /home/sripathi/17794/patch_2.6.13.1/exit.c 2005-09-12 02:46:15.000000000
-0500
@@ -463,9 +463,11 @@ static inline void __exit_fs(struct task
struct fs_struct * fs = tsk->fs;
if (fs) {
- task_lock(tsk);
- tsk->fs = NULL;
- task_unlock(tsk);
+ if (!thread_group_leader(tsk) || !atomic_read(&tsk->signal->live)) {
+ task_lock(tsk);
+ tsk->fs = NULL;
+ task_unlock(tsk);
+ }
__put_fs_struct(fs);
}
}
A comment in there would be nice.
Below is the patch with a comment.
Thanks and regards,
Sripathi.
Signed-off-by: Sripathi Kodi <sripathik@xxxxxxxxxx>
--- linux-2.6.13.1/kernel/exit.c 2005-09-13 15:39:48.738542872 -0500
+++ /home/sripathi/17794/patch_2.6.13.1/exit.c 2005-09-13 15:39:27.367791720
-0500
@@ -463,9 +463,13 @@ static inline void __exit_fs(struct task
struct fs_struct * fs = tsk->fs;
if (fs) {
- task_lock(tsk);
- tsk->fs = NULL;
- task_unlock(tsk);
+ /* If tsk is thread group leader and if group still has alive
+ * threads, those threads may use tsk->fs */
+ if (!thread_group_leader(tsk) || !atomic_read(&tsk->signal->live)) {
+ task_lock(tsk);
+ tsk->fs = NULL;
+ task_unlock(tsk);
+ }
__put_fs_struct(fs);
}
}
-
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