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Tue, 6 Feb 2024 12:03:42 -0500 (EST) Date: Tue, 6 Feb 2024 10:03:41 -0700 From: Tycho Andersen To: Oleg Nesterov Cc: Christian Brauner , Andy Lutomirski , "Eric W. Biederman" , linux-kernel@vger.kernel.org Subject: Re: [PATCH] pidfd: change do_notify_pidfd() to use __wake_up(poll_to_key(EPOLLIN)) Message-ID: References: <20240205141348.GA16539@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240205141348.GA16539@redhat.com> On Mon, Feb 05, 2024 at 03:13:48PM +0100, Oleg Nesterov wrote: > rather than wake_up_all(). This way do_notify_pidfd() won't wakeup the > POLLHUP-only waiters which wait for pid_task() == NULL. > > TODO: > - as Christian pointed out, this asks for the new wake_up_all_poll() > helper, it can already have other users. > > - we can probably discriminate the PIDFD_THREAD and non-PIDFD_THREAD > waiters, but this needs more work. See > https://lore.kernel.org/all/20240205140848.GA15853@redhat.com/ > > Signed-off-by: Oleg Nesterov Reviewed-by: Tycho Andersen