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Date: Wed, 14 Oct 2015 20:51:53 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>, Rik van Riel <riel@redhat.com>,
        Christoph Lameter <cl@linux.com>, Tejun Heo <tj@kernel.org>,
        Rusty Russell <rusty@rustcorp.com.au>, linux-kernel@vger.kernel.org
Subject: [PATCH 0/1] Revert "kmod: handle UMH_WAIT_PROC from system unbound
	workqueue"
Message-ID: <20151014185153.GA8117@redhat.com>
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Hello,

I noticed by accident the kworker zombies on my testing machine.
Can't reproduce (although I think it won't be hard to make a
test-case), but I think the reason is clear, see the changelog.

We could fix this by using kthread_create() if !UMH_WAIT_PROC,
but imo it would be better to revert this change at least for
now. If we really want to avoid the extra kernel_thread(), we
can make another patch which also avoids sys_wait4() and the
games with SIGCHLD; we can rely on wait_chldexit.

Oleg.