From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Subject: Re: [PATCH 2/5] pidfd: add pidfd_wait() Date: Thu, 25 Jul 2019 12:16:27 +0200 Message-ID: <20190725101626.GD4707@redhat.com> References: <20190724144651.28272-1-christian@brauner.io> <20190724144651.28272-3-christian@brauner.io> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190724144651.28272-3-christian@brauner.io> Sender: linux-kernel-owner@vger.kernel.org To: Christian Brauner Cc: linux-kernel@vger.kernel.org, arnd@arndb.de, ebiederm@xmission.com, keescook@chromium.org, joel@joelfernandes.org, tglx@linutronix.de, tj@kernel.org, dhowells@redhat.com, jannh@google.com, luto@kernel.org, akpm@linux-foundation.org, cyphar@cyphar.com, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, kernel-team@android.com, linux-api@vger.kernel.org List-Id: linux-api@vger.kernel.org On 07/24, Christian Brauner wrote: > > +SYSCALL_DEFINE6(pidfd_wait, int, pidfd, int __user *, stat_addr, > + siginfo_t __user *, info, struct rusage __user *, ru, > + unsigned int, states, unsigned int, flags) > +{ Oh, I too think that P_PIDFD makes more sense. and could you explain in the changelog why? I am not arguing and if nothing else this is consistent with other pidfd features, but if you are parent/debugger you can't hit the problem with pid-reuse, unless you races with your sub-threads. Oleg.