From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932494Ab0KLPjs (ORCPT ); Fri, 12 Nov 2010 10:39:48 -0500 Received: from ms01.sssup.it ([193.205.80.99]:36831 "EHLO sssup.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932209Ab0KLPjr (ORCPT ); Fri, 12 Nov 2010 10:39:47 -0500 Subject: Re: [RFC][PATCH 17/22] sched: add signaling overrunning -deadline tasks. From: Raistlin To: Peter Zijlstra Cc: Ingo Molnar , Thomas Gleixner , Steven Rostedt , Chris Friesen , oleg@redhat.com, Frederic Weisbecker , Darren Hart , Johan Eker , "p.faure" , linux-kernel , Claudio Scordino , michael trimarchi , Fabio Checconi , Tommaso Cucinotta , Juri Lelli , Nicola Manica , Luca Abeni , Dhaval Giani , Harald Gustafsson , paulmck In-Reply-To: <1289512701.2084.197.camel@laptop> References: <1288333128.8661.137.camel@Palantir> <1288334428.8661.158.camel@Palantir> <1289512701.2084.197.camel@laptop> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-zr/D79Q8OLhxN4K599Of" Date: Fri, 12 Nov 2010 16:39:32 +0100 Message-ID: <1289576372.6525.512.camel@Palantir> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-zr/D79Q8OLhxN4K599Of Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2010-11-11 at 22:58 +0100, Peter Zijlstra wrote: > On Fri, 2010-10-29 at 08:40 +0200, Raistlin wrote: > > +static inline void __dl_signal(struct task_struct *tsk, int which) > > +{ > > + struct siginfo info; > > + long long amount =3D which =3D=3D SF_SIG_DMISS ? tsk->dl.stats.= last_dmiss : > > + tsk->dl.stats.last_rorun; > > + > > + info.si_signo =3D SIGXCPU; > > + info.si_errno =3D which; > > + info.si_code =3D SI_KERNEL; > > + info.si_pid =3D 0; > > + info.si_uid =3D 0; > > + info.si_value.sival_int =3D (int)amount; > > + > > + /* Correctly take the locks on task's sighand */ > > + __group_send_sig_info(SIGXCPU, &info, tsk); > > + /* Log what happened to dmesg */ > > + printk(KERN_INFO "SCHED_DEADLINE: 0x%4x by %Ld [ns] in %d (%s)\= n", > > + which, amount, task_pid_nr(tsk), tsk->comm); > > +}=20 >=20 > This being a G-EDF like scheduler with a u<=3D1 schedulability test, we'r= e > firmly in soft-rt territory which means the above will be very easy to > trigger.. Maybe not spam dmesg? > Ok, right. Maybe, if I add the SF_HARD_RT flag (and force the hard tasks to run on a single CPU they must specify) I can keep the notification for those tasks only. What do you think? Thanks, Dario --=20 <> (Raistlin Majere) ---------------------------------------------------------------------- Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa (Italy) http://blog.linux.it/raistlin / raistlin@ekiga.net / dario.faggioli@jabber.org --=-zr/D79Q8OLhxN4K599Of Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEABECAAYFAkzdX7QACgkQk4XaBE3IOsStSgCcCUyoK92sibqFHwUCdIgTrieR CnMAni5o9vsC6ipwpEKGBOR8IwCcfhX8 =J8Eu -----END PGP SIGNATURE----- --=-zr/D79Q8OLhxN4K599Of--