Quoting Chris Wilson (2019-07-08 14:39:35) > Quoting Tvrtko Ursulin (2019-07-08 13:24:39) > > > > On 08/07/2019 13:16, Chris Wilson wrote: > > > Quoting Tvrtko Ursulin (2019-07-08 13:10:34) > > >> > > >> On 08/07/2019 12:19, Chris Wilson wrote: > > >>> Avoid a global idle barrier by reconfiguring each context by rewriting > > >>> them with MI_STORE_DWORD from the kernel context. > > >>> > > >>> v2: We only need to determine the desired register values once, they are > > >>> the same for all contexts. > > >>> > > >>> Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > >>> Cc: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx> > > >>> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > > >>> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx> > > >>> --- > > >>> drivers/gpu/drm/i915/gem/i915_gem_context.c | 2 + > > >>> drivers/gpu/drm/i915/gt/intel_lrc.c | 7 +- > > >>> drivers/gpu/drm/i915/i915_perf.c | 248 +++++++++++++++----- > > >>> 3 files changed, 195 insertions(+), 62 deletions(-) > > >>> > > >>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c > > >>> index e367dce2a696..1f0d10bb88c1 100644 > > >>> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c > > >>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c > > >>> @@ -624,7 +624,9 @@ i915_gem_context_create_kernel(struct drm_i915_private *i915, int prio) > > >>> ctx->sched.priority = I915_USER_PRIORITY(prio); > > >>> ctx->ring_size = PAGE_SIZE; > > >>> > > >>> + /* Isolate the kernel context from prying eyes and sticky fingers */ > > >>> GEM_BUG_ON(!i915_gem_context_is_kernel(ctx)); > > >>> + list_del_init(&ctx->link); > > >> > > >> Why exactly? > > > > > > Otherwise we recursively try to modify the context. > > > > From gen8_configure_all_contexts, twice, or really recursively? If > > former isn't that solvable by simply skipping kernel contexts in the > > first loop? > > > > >> Any repercussions for i915_sysfs/i915_l3_write? debugfs I gather you > > >> won't care about? > > > > > > No, because what matters for those is user contexts. > > > > There isn't some time cost associated with l3_remap calls when switching > > contexts? > > No, it's even weirder than that as it is not a context register (at > least on hsw where we support it). I guess, we should just unlazy and emit > a request from the sysfs. Actually, I am wrong here. The L3 remapping registers do appear to be saved in the context image. At least that is what my testing indicates. I can still argue that they don't apply to the kernel context. But my plan to remove the walk over GEM contexts and the lazy update fails. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
