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Date: Wed, 31 Jan 2024 15:12:04 +0100
From: Oleg Nesterov <oleg@redhat.com>
To: Christian Brauner <brauner@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
	Tycho Andersen <tycho@tycho.pizza>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 0/1] pidfd: implement PIDFD_THREAD flag for
 pidfd_open()
Message-ID: <20240131141204.GA24130@redhat.com>
References: <20240131132541.GA23632@redhat.com>
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User-Agent: Mutt/1.5.24 (2015-08-30)

Before I forget this...

After this patch we can easily add another feature, pidfd_poll()
can add, say, POLLHUP to poll_flags if the pid is "dead".

So the user can do

	poll(pidfd, { .revents = POLLHUP });

and it will block until release_task() is called and this pid is
no longer in use (pid_task() == NULL).

Do you think this can be useful?

Oleg.