diff options
| author | Robert Bragg <robert@sixbynine.org> | 2017-05-11 16:43:30 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2017-05-13 11:03:17 +0100 |
| commit | 4117ebc74cb3ca25966488b8da6157a299f02e92 (patch) | |
| tree | fed4f5ba39af96f55cbe8b15dccc44e6ec9ce42a /drivers/gpu/drm/i915/i915_perf.c | |
| parent | 52c57c263f14f90ebf43705d1c9cc4d53229fd7c (diff) | |
drm/i915/perf: better pipeline aged/aging tail updates
This updates the tail pointer race workaround handling to updating the
'aged' pointer before looking to start aging a new one. There's the
possibility that there is already new data available and so we can
immediately start aging a new pointer without having to first wait for a
later hrtimer callback (and then another to age).
Signed-off-by: Robert Bragg <robert@sixbynine.org>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170511154345.962-8-lionel.g.landwerlin@intel.com
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_perf.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_perf.c | 41 |
1 files changed, 23 insertions, 18 deletions
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index 957b959ea67d..4d31b70df452 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -391,6 +391,29 @@ static bool gen7_oa_buffer_check_unlocked(struct drm_i915_private *dev_priv) now = ktime_get_mono_fast_ns(); + /* Update the aged tail + * + * Flip the tail pointer available for read()s once the aging tail is + * old enough to trust that the corresponding data will be visible to + * the CPU... + * + * Do this before updating the aging pointer in case we may be able to + * immediately start aging a new pointer too (if new data has become + * available) without needing to wait for a later hrtimer callback. + */ + if (aging_tail != INVALID_TAIL_PTR && + ((now - dev_priv->perf.oa.oa_buffer.aging_timestamp) > + OA_TAIL_MARGIN_NSEC)) { + aged_idx ^= 1; + dev_priv->perf.oa.oa_buffer.aged_tail_idx = aged_idx; + + aged_tail = aging_tail; + + /* Mark that we need a new pointer to start aging... */ + dev_priv->perf.oa.oa_buffer.tails[!aged_idx].offset = INVALID_TAIL_PTR; + aging_tail = INVALID_TAIL_PTR; + } + /* Update the aging tail * * We throttle aging tail updates until we have a new tail that @@ -420,24 +443,6 @@ static bool gen7_oa_buffer_check_unlocked(struct drm_i915_private *dev_priv) } } - /* Update the aged tail - * - * Flip the tail pointer available for read()s once the aging tail is - * old enough to trust that the corresponding data will be visible to - * the CPU... - */ - if (aging_tail != INVALID_TAIL_PTR && - ((now - dev_priv->perf.oa.oa_buffer.aging_timestamp) > - OA_TAIL_MARGIN_NSEC)) { - aged_idx ^= 1; - dev_priv->perf.oa.oa_buffer.aged_tail_idx = aged_idx; - - aged_tail = aging_tail; - - /* Mark that we need a new pointer to start aging... */ - dev_priv->perf.oa.oa_buffer.tails[!aged_idx].offset = INVALID_TAIL_PTR; - } - spin_unlock_irqrestore(&dev_priv->perf.oa.oa_buffer.ptr_lock, flags); return aged_tail == INVALID_TAIL_PTR ? |