Messages in this thread | | | Date | Thu, 15 Oct 2015 15:37:39 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 1/1] Revert "kmod: handle UMH_WAIT_PROC from system unbound workqueue" |
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On Wed, Oct 14, 2015 at 08:52:09PM +0200, Oleg Nesterov wrote: > This reverts commit bb304a5c6fc63d8506cd9741a3a5f35b73605625. > > Because this patch leads to kthread zombies. > > call_usermodehelper_exec_sync() does fork() + wait() with "unignored" > SIGCHLD. What we have missed is that this worker thread can have other > children previously forked by call_usermodehelper_exec_work() without > UMH_WAIT_PROC. If such a child exits in between it becomes a zombie > and nobody can reap it (unless/until this worker thread exits too).
I missed that indeed. But then when we create the async thread with UMH_NO_WAIT, who reaps it? It's created by the workqueue which never exits.
And on others cases, who buries the sync thread?
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