From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lennart Poettering Subject: Re: [PATCH] prctl.2: PR_{SET,GET}_CHILD_SUBREAPER Date: Fri, 11 Jan 2013 17:00:47 +0100 Message-ID: <20130111160047.GA30380@tango.0pointer.de> References: <1344233940-2680-4-git-send-email-shawnlandden@gmail.com> <50240ad3.6ae4440a.5977.ffffc0ce@mx.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Michael Kerrisk (man-pages)" Cc: shawnlandden-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Kay Sievers , Oleg Nesterov List-Id: linux-man@vger.kernel.org On Thu, 10.01.13 23:51, Michael Kerrisk (man-pages) (mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org) wrote: Hey, sorry for never doing the doc work! Here are my comments: > > +.BR PR_SET_CHILD_SUBREAPER " (since Linux 3.3)" > > +Sets a process, such as a service manager, such that orphan (double-forking) > > +child processes re-parent to this process instead of > > +.BR init (8). I don't like this reference to "double-forking" here. After all, this also applies to triple-forking, quadruple-forking and even quintuple-forking... ;-) Expressing this is difficult, but here's my try: "Enables that the process becomes a 'subreaper' for all its (immediate or indirect) offspring processes. Any process whose immediate parent dies and whose ancestry includes a process where this flag is set will be reparented to the closest process with this flag set, instead of PID 1. A 'subreaper' hence receives SIGHCLD signals for any orphaned offspring processes, that otherwise would be received by the init process." > > +The service manager > > +is able to receive > > +.B SIGCHLD > > +signals and is able to investigate the process until > > +it calls > > +.BR wait (2). Drop this. > > +All children of this process will inherit a flag if they should > > +look for a child_subreaper process at exit. Set This bit should go, it's an inplementation detail, als Kay already pointed out. > > +.I arg2 > > +to 1 or 0 to enable or disable, respectively. > > +.TP > > +.BR PR_GET_CHILD_SUBREAPER " (since Linux 3.3)" > > +Returns whether calling process is a child subreaper (see > > +.BR PR_SET_CHILD_SUBREAPER ), > > +in the location pointed to by > > +.IR "(int\ *) arg2" . > > +.TP > > .BR PR_SET_SECUREBITS " (since Linux 2.6.26)" > > Set the "securebits" flags of the calling thread to the value supplied in > > .IR arg2 . > > Otherwise sounds good. Lennart -- Lennart Poettering - Red Hat, Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html