From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56104) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bfvwZ-0007wq-3V for qemu-devel@nongnu.org; Fri, 02 Sep 2016 17:24:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bfvwV-0003u8-2M for qemu-devel@nongnu.org; Fri, 02 Sep 2016 17:24:11 -0400 Received: from mail-qk0-x243.google.com ([2607:f8b0:400d:c09::243]:36467) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bfvwU-0003u2-Ts for qemu-devel@nongnu.org; Fri, 02 Sep 2016 17:24:06 -0400 Received: by mail-qk0-x243.google.com with SMTP id v123so8600914qkh.3 for ; Fri, 02 Sep 2016 14:24:06 -0700 (PDT) Date: Fri, 2 Sep 2016 17:24:04 -0400 From: Stefan Hajnoczi Message-ID: <20160902212404.GH21771@stefanha-x1.localdomain> References: <1470756748-18933-1-git-send-email-berrange@redhat.com> <1470756748-18933-61-git-send-email-berrange@redhat.com> <87shucr8vo.fsf@fimbulvetr.bsc.es> <20160810145125.GP13393@redhat.com> <87eg5wppsj.fsf@fimbulvetr.bsc.es> <20160811081317.GA27458@redhat.com> <87ziojlio5.fsf@fimbulvetr.bsc.es> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="VbfcI4OLZ4XW0yH2" Content-Disposition: inline In-Reply-To: <87ziojlio5.fsf@fimbulvetr.bsc.es> Subject: Re: [Qemu-devel] [PATCH for-2.8 v1 60/60] trace: update docs to reflect new code generation approach List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" , qemu-devel@nongnu.org, Stefan Hajnoczi --VbfcI4OLZ4XW0yH2 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 11, 2016 at 12:11:06PM +0200, Llu=EDs Vilanova wrote: > Daniel P Berrange writes: >=20 > > On Wed, Aug 10, 2016 at 06:11:24PM +0200, Llu=EDs Vilanova wrote: > >> Daniel P Berrange writes: > >>=20 > >> > On Wed, Aug 10, 2016 at 04:33:47PM +0200, Llu=EDs Vilanova wrote: > >> >> Daniel P Berrange writes: > [...] > >> >> For example, first we concatenate /trace-events, /io/trace-events a= nd > >> >> /hw/usb/trace-events into /trace-events-all to produce: > >> >>=20 > >> >> @group core > >> >> @dir / > >> >> # contents of /trace-events > >> >> @group io > >> >> @dir /io > >> >> # contents of /io/trace-events > >> >> @group hw_usb > >> >> @dir /hw/usb > >> >> # contents of /hw/usb/trace-events > >> >>=20 > >> >> Then we can use /trace-events-all to generate all the per-directory= trace.h > >> >> files while ensuring a perfectly flat event identifier space (a sin= gle > >> >> generated-events.c is used). > >> >>=20 > >> >> This should minimize changes to tracing code and avoid further rest= rictions > >> >> (like the "top-level vcpu" one). > >>=20 > >> > That means when any individual trace file is changed, we re-generate= the > >> > world, which is exactly what this series is designed to avoid. > >>=20 > >> Nope. We re-generate /trace-events-all, but each individual file gener= ated > >> afterwards (taken from the "@dir" directive) will change only if its n= ew > >> contents do (the Makefile uses cmp to check if files need updating fro= m their > >> corresponding timestamp file). >=20 > > The contents will still need to change too if we have a global numbering > > space as your suggestion requires. The event groups are the only way to > > avoid that. >=20 > Aha, that's true. I didn't think of that, sorry. Nevertheless, I agree that @id_offset() should be eliminated to avoid collisions and manual effort when trace-events files are added. --VbfcI4OLZ4XW0yH2 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJXye30AAoJEJykq7OBq3PIae0H/0L0Mje3VSNbx98qG8u6Roz4 VhWsIdOGaTBs6kViFs7MRLcnGFNDw2xej2JjLUDRom/prcg7wAkgBc4DfZzFry0N C8E3Rvo5TsWU7lX7AqDOblXepKsvIZE88VMFR4ryA0MBWigM3UEAZhvD3/UCB8+n HTCMTdu8TDr3dfd3GryDBfcyjDIbnpIwFoxIhySypnYcUojJnfeM9Zjzjd8AT3qr gfFz77JhGTUw/BIkweJ3bKXuar+sH9dOw5PvBKq0l5pUO+tCpGJNvJZHBDwvAAHn w9JRw8v1LrlC/VC3lTDnHAVQB8Nl8uA3puaeK22Y/XGu+12VE76yJ1+8xfJexfU= =CLxB -----END PGP SIGNATURE----- --VbfcI4OLZ4XW0yH2--