From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:41217) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gtmhD-0004do-Jk for qemu-devel@nongnu.org; Wed, 13 Feb 2019 00:02:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gtmZX-0002R7-53 for qemu-devel@nongnu.org; Tue, 12 Feb 2019 23:55:00 -0500 Date: Wed, 13 Feb 2019 15:54:27 +1100 From: David Gibson Message-ID: <20190213045427.GK1884@umbus.fritz.box> References: <20190128094625.4428-1-clg@kaod.org> <20190128094625.4428-8-clg@kaod.org> <20190212055900.GN1884@umbus.fritz.box> <56a5772ae88c5b5f65c969e2191a02d62cca5055.camel@kernel.crashing.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="n0t7pLec3q0yZKtb" Content-Disposition: inline In-Reply-To: <56a5772ae88c5b5f65c969e2191a02d62cca5055.camel@kernel.crashing.org> Subject: Re: [Qemu-devel] [PATCH 07/19] target/ppc: Make special ORs match x86 pause and don't generate on mttcg List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Benjamin Herrenschmidt Cc: =?iso-8859-1?Q?C=E9dric?= Le Goater , qemu-ppc@nongnu.org, qemu-devel@nongnu.org --n0t7pLec3q0yZKtb Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Feb 13, 2019 at 11:03:12AM +1100, Benjamin Herrenschmidt wrote: > On Tue, 2019-02-12 at 16:59 +1100, David Gibson wrote: > > On Mon, Jan 28, 2019 at 10:46:13AM +0100, C=E9dric Le Goater wrote: > > > From: Benjamin Herrenschmidt > > >=20 > > > There's no point in going out of translation on an SMT OR with > > > mttcg since the backend won't do anything useful such as pausing, > > > it's only useful on traditional TCG to give time to other > > > processors. > >=20 > > Is it actively harmful in the MTTCG case, or just pointless? >=20 > I think it can hurt performance, I don't remember for sure :) >=20 > > > Signed-off-by: Benjamin Herrenschmidt > > > Signed-off-by: C=E9dric Le Goater > > > --- > > > target/ppc/translate.c | 6 ++++-- > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > >=20 > > > diff --git a/target/ppc/translate.c b/target/ppc/translate.c > > > index e169c43643a1..7d40a1fbe6bd 100644 > > > --- a/target/ppc/translate.c > > > +++ b/target/ppc/translate.c > > > @@ -1580,7 +1580,7 @@ static void gen_pause(DisasContext *ctx) > > > tcg_temp_free_i32(t0); > > > =20 > > > /* Stop translation, this gives other CPUs a chance to run */ > > > - gen_exception_nip(ctx, EXCP_HLT, ctx->base.pc_next); > > > + gen_exception_nip(ctx, EXCP_INTERRUPT, ctx->base.pc_next); > >=20 > > I don't see how this change relates to the rest. >=20 > Yeah not sure anymore :-) Oh. That certainly doesn't make this easier to review. So, all these target/ppc patches are only indirectly related to XIVE pnv support. C=E9dric, can you split them out into their own series on the next spin. >=20 > > > } > > > #endif /* defined(TARGET_PPC64) */ > > > =20 > > > @@ -1662,7 +1662,9 @@ static void gen_or(DisasContext *ctx) > > > * than no-op, e.g., miso(rs=3D26), yield(27), mdoio(29), md= oom(30), > > > * and all currently undefined. > > > */ > > > - gen_pause(ctx); > > > + if (!mttcg_enabled) { > > > + gen_pause(ctx); > > > + } > > > #endif > > > #endif > > > } >=20 --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --n0t7pLec3q0yZKtb Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAlxjowMACgkQbDjKyiDZ s5LAxBAA5ziEApJAyFoPgveyXZvh4svGQjB2C1mMSthO9Q/WUL4LYsjbIJQZYLP0 +SJ6+Z2UJ7CNhuvohr/+4byNy8RHAs0bNk6BqhQ0QxRQBY4b5/olsMpxJolbt7JS bbZbbY/OWep2W8G8J9vaWhV8F7OUNL1Ph/QJJyUV92zJGCOWcMsq1kdlbS/Gf92i acZHPZd4Otel50yeFwsd9cTqtJB91GDungY7/0BBYMp8BiA10eEkQCDPG+RjxCNq XD9WTOEiOi925x9CbIw9ZtgoM3kmNLy7ERbAB/INR9hUufIgcN7Bsr8acbyYL8Ji DvB/vjn2zg5R9DkXE+vDElz2ILIcxJwqifMU3LFrtog8kZS00ZjleyA/oB/UjClR UXimjWyKfzfeh2DvPUKr5KRyq/GNEGn/s/k9u9Rrl3Q1VG+ileemvOIaupUK0c6Q jhudOFxpRpOvnye4ZdfIifF4H8vX/m9d2uxmYTrx1IC4A+1rwHAYRVObihTrocXr Ju0gsh4lWoXf24/i8XqHtQGoZGj1TUqmqsi0pKmhOoT0AdJeES6sxdBof2J7gyTj z0EX7HvyLfypTTnc10NsVuqZzXf665LnasYrFi0hPtsyiS+K9L7GKPMaQYfW7FkB VprNYYnjxY/vbSqHdgWP4j8OVUaUqTX2VLI0MbgJ5YwnhaEqf0M= =DXjX -----END PGP SIGNATURE----- --n0t7pLec3q0yZKtb--