Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59004 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750851AbdAaFLt (ORCPT ); Tue, 31 Jan 2017 00:11:49 -0500 Date: Tue, 31 Jan 2017 06:11:53 +0100 From: Greg KH To: Francisco Jerez 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. Message-ID: <20170131051153.GB3954@kroah.com> References: <1485782369118204@kroah.com> <20170130202445.6674-1-currojerez@riseup.net> <20170131051125.GA3954@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170131051125.GA3954@kroah.com> Sender: stable-owner@vger.kernel.org List-ID: 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). > > > > 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. > > > > 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). > > > > v2: Drop some more code to avoid unused variable warning. > > > > Fixes: 738fa1b3123f ("drm/i915/kbl: Add WaDisableLSQCROPERFforOCL") > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99256 > > 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(-) > > What is the commit id of this patch in Linus's tree? Ah, nevermind, it's 4fc020d864647ea3ae8cb8f17d63e48e87ebd0bf, right? thanks, greg k-h