• Lionel Landwerlin's avatar
    drm/i915/perf: introduce global sseu pinning · 11ecbddd
    Lionel Landwerlin authored
    On Gen11 powergating half the execution units is a functional
    requirement when using the VME samplers. Not fullfilling this
    requirement can lead to hangs.
    
    This unfortunately plays fairly poorly with the NOA requirements. NOA
    requires a stable power configuration to maintain its configuration.
    
    As a result using OA (and NOA feeding into it) so far has required us
    to use a power configuration that can work for all contexts. The only
    power configuration fullfilling this is powergating half the execution
    units.
    
    This makes performance analysis for 3D workloads somewhat pointless.
    
    Failing to find a solution that would work for everybody, this change
    introduces a new i915-perf stream open parameter that punts the
    decision off to userspace. If this parameter is omitted, the existing
    Gen11 behavior remains (half EU array powergating).
    
    This change takes the initiative to move all perf related sseu
    configuration into i915_perf.c
    
    v2: Make parameter priviliged if different from default
    
    v3: Fix context modifying its sseu config while i915-perf is enabled
    
    v4: Always consider global sseu a privileged operation (Tvrtko)
        Override req_sseu point in intel_sseu_make_rpcs() (Tvrtko)
        Remove unrelated changes (Tvrtko)
    
    v5: Some typos (Tvrtko)
        Process sseu param in read_properties_unlocked() (Tvrtko)
    
    v6: Actually commit the bits from v5...
        Fixup some checkpath warnings
    
    v7: Only compare engine uabi field (Chris)
    Signed-off-by: default avatarLionel Landwerlin <lionel.g.landwerlin@intel.com>
    Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20200317132222.2638719-3-lionel.g.landwerlin@intel.com
    11ecbddd
i915_gem_context.c 62.3 KB