From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754367AbZB1Iqr (ORCPT ); Sat, 28 Feb 2009 03:46:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752065AbZB1Iqj (ORCPT ); Sat, 28 Feb 2009 03:46:39 -0500 Received: from rv-out-0506.google.com ([209.85.198.235]:32432 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752018AbZB1Iqi (ORCPT ); Sat, 28 Feb 2009 03:46:38 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:reply-to:in-reply-to:references:date:message-id :subject:from:to:cc:content-type:content-transfer-encoding; b=Y2cbtsp7Tss4yj3YNpD8iA7yjSUj86SdINOcdCDLyc5b86y20ch9z3eg90Spgzekpu LaCA7ZxEMXD/9ELT5vvmQVfChFTOF8L/m8JzOSjO5In45wCzxJFAb/Cue/nh9sJSbGAr LIwd49g/KDUDl2kpENBfSARvylNoYmOzTdlOo= MIME-Version: 1.0 Reply-To: mtk.manpages@gmail.com In-Reply-To: <20090228024424.D237CFC3DA@magilla.sf.frob.com> References: <20090226133339.875832967@linutronix.de> <20090228024424.D237CFC3DA@magilla.sf.frob.com> Date: Sat, 28 Feb 2009 21:46:35 +1300 Message-ID: Subject: Re: [patch 0/3] add rt_tgsigqueueinfo syscall [RESEND] From: Michael Kerrisk To: Roland McGrath Cc: Thomas Gleixner , LKML , Oleg Nesterov , Ingo Molnar , Linux API , drepper@redhat.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/28/09, Roland McGrath wrote: >> With respect to the first point, it seems to me reasonably likely that >> there would be use cases where the receiving thread wants to know the >> thread ID of the sender -- especially when sender and receiver are in >> the same process. > > But expecting si_pid to play that role is bizarre. Oh -- I wasn't suggeting that si_pid do that task; I was instead wondering if we needed an additional si_threadid field (or some such). > It's never what any > POSIX-like program would do, both since POSIX says si_pid is a process ID, > and because there are no POSIX-like interfaces at all that use Linux TIDs > to refer to threads. (Nod.) > Wanting this only seems plausible within one process. We are in agreement. > In that case, sender > and recipient know they share memory. The normal thing to do (and what > POSIX applications will do) is to store that info somewhere pointed to by > the sigval. Good point. That would be another of dealing with point I wondered about, and probably better than my idea. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git man-pages online: http://www.kernel.org/doc/man-pages/online_pages.html Found a bug? http://www.kernel.org/doc/man-pages/reporting_bugs.html