From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.riseup.net ([198.252.153.129]:46581 "EHLO mx1.riseup.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750942AbdAaFSF (ORCPT ); Tue, 31 Jan 2017 00:18:05 -0500 From: Francisco Jerez To: Greg KH Cc: stable@vger.kernel.org, eero.t.tamminen@intel.com, jani.nikula@intel.com, matthew.william.auld@gmail.com, mika.kuoppala@intel.com, beignet@lists.freedesktop.org Subject: Re: [PATCH] drm/i915: Remove WaDisableLSQCROPERFforOCL KBL workaround. In-Reply-To: <20170131051153.GB3954@kroah.com> References: <1485782369118204@kroah.com> <20170130202445.6674-1-currojerez@riseup.net> <20170131051125.GA3954@kroah.com> <20170131051153.GB3954@kroah.com> Date: Mon, 30 Jan 2017 21:11:43 -0800 Message-ID: <8760kvq0ds.fsf@riseup.net> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="==-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: stable-owner@vger.kernel.org List-ID: --==-=-= Content-Type: multipart/mixed; boundary="=-=-=" --=-=-= Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Greg KH writes: > On Tue, Jan 31, 2017 at 06:11:25AM +0100, Greg KH wrote: >> On Mon, Jan 30, 2017 at 12:24:45PM -0800, Francisco Jerez wrote: >> > The WaDisableLSQCROPERFforOCL workaround has the side effect of >> > disabling an L3SQ optimization that has huge performance implications >> > and is unlikely to be necessary for the correct functioning of usual >> > graphic workloads. Userspace is free to re-enable the workaround on >> > demand, and is generally in a better position to determine whether the >> > workaround is necessary than the DRM is (e.g. only during the >> > execution of compute kernels that rely on both L3 fences and HDC R/W >> > requests). >> >=20 >> > The same workaround seems to apply to BDW (at least to production >> > stepping G1) and SKL as well (the internal workaround database claims >> > that it does for all steppings, while the BSpec workaround table only >> > mentions pre-production steppings), but the DRM doesn't do anything >> > beyond whitelisting the L3SQCREG4 register so userspace can enable it >> > when it sees fit. Do the same on KBL platforms. >> >=20 >> > Improves performance of the GFXBench4 gl_manhattan31 benchmark by 60%, >> > and gl_4 (AKA car chase) by 14% on a KBL GT2 running Mesa master -- >> > This is followed by a regression of 35% and 10% respectively for the >> > same benchmarks and platform caused by my recent patch series >> > switching userspace to use the dataport constant cache instead of the >> > sampler to implement uniform pull constant loads, which caused us to >> > hit more heavily the L3 cache (and on platforms other than KBL had the >> > opposite effect of improving performance of the same two benchmarks). >> > The overall effect on KBL of this change combined with the recent >> > userspace change is respectively 4.6% and 2.6%. SynMark2 OglShMapPcf >> > was affected by the constant cache changes (though it improved as it >> > did on other platforms rather than regressing), but is not >> > significantly affected by this patch (with statistical significance of >> > 5% and sample size 20). >> >=20 >> > v2: Drop some more code to avoid unused variable warning. >> >=20 >> > Fixes: 738fa1b3123f ("drm/i915/kbl: Add WaDisableLSQCROPERFforOCL") >> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=3D99256 >> > Signed-off-by: Francisco Jerez >> > Cc: Matthew Auld >> > Cc: Eero Tamminen >> > Cc: Jani Nikula >> > Cc: Mika Kuoppala >> > Cc: beignet@lists.freedesktop.org >> > Cc: # v4.7+ >> > Reviewed-by: Mika Kuoppala >> > [Removed double Fixes tag] >> > Signed-off-by: Mika Kuoppala >> > Link: http://patchwork.freedesktop.org/patch/msgid/1484217894-20505-1-= git-send-email-mika.kuoppala@intel.com >> > (cherry picked from commit 8726f2faa371514fba2f594d799db95203dfeee0) >> > Signed-off-by: Jani Nikula >> > [ Francisco Jerez: Rebase on v4.9 branch. ] >> > Signed-off-by: Francisco Jerez >> > --- >> > drivers/gpu/drm/i915/intel_lrc.c | 3 +-- >> > drivers/gpu/drm/i915/intel_ringbuffer.c | 8 -------- >> > 2 files changed, 1 insertion(+), 10 deletions(-) >>=20 >> What is the commit id of this patch in Linus's tree? > > Ah, nevermind, it's 4fc020d864647ea3ae8cb8f17d63e48e87ebd0bf, right? > Oops, yes, that's right. Thanks! > thanks, > > greg k-h --=-=-=-- --==-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iF4EAREIAAYFAliQHI8ACgkQg5k4nX1Sv1suZQEAntIz5KXFmO0Kyai22qWPYSTe Xo5VO49Ym7JQhy9YoswA/33dF5noDpTLdL0tvjziRdbeuWdKdxpb84cWhIxEBdQP =QntP -----END PGP SIGNATURE----- --==-=-=--