| Message ID | 1404147071-2911-2-git-send-email-rodrigo.vivi@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jun 30, 2014 at 09:51:10AM -0700, Rodrigo Vivi wrote: > On Broadwell GT3 we have 2 Video Command Streamers (VCS), > but userspace has no control when using VCS1 or VCS2. So we cannot test, > validate or debug specific changes or workaround that might affect only > one or another ring. So this patch introduces a mechanism to avoid the > ping-pong selection and use one specific ring given at boot time. > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> I think going the debugfs route is the right thing to do if this should move forward. If the goal is only for test, then I'm not really in favor of moving it forward. > --- > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 34 ++++++++++++++++++------------ > drivers/gpu/drm/i915/i915_params.c | 6 ++++++ > 3 files changed, 27 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 8cea596..7b6614f 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -2069,6 +2069,7 @@ struct i915_params { > int panel_ignore_lid; > unsigned int powersave; > int semaphores; > + int dual_bsd_ring; > unsigned int lvds_downclock; > int lvds_channel_mode; > int panel_use_ssc; > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > index d815ef5..09f350e 100644 > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > @@ -1035,26 +1035,32 @@ static int gen8_dispatch_bsd_ring(struct drm_device *dev, > { > struct drm_i915_private *dev_priv = dev->dev_private; > struct drm_i915_file_private *file_priv = file->driver_priv; > + int ring_id; > + int dual = i915.dual_bsd_ring; > > /* Check whether the file_priv is using one ring */ > if (file_priv->bsd_ring) > return file_priv->bsd_ring->id; > - else { > - /* If no, use the ping-pong mechanism to select one ring */ > - int ring_id; > > - mutex_lock(&dev->struct_mutex); > - if (dev_priv->mm.bsd_ring_dispatch_index == 0) { > - ring_id = VCS; > - dev_priv->mm.bsd_ring_dispatch_index = 1; > - } else { > - ring_id = VCS2; > - dev_priv->mm.bsd_ring_dispatch_index = 0; > - } > - file_priv->bsd_ring = &dev_priv->ring[ring_id]; > - mutex_unlock(&dev->struct_mutex); > - return ring_id; > + /* If no, use the parameter defined or ping-pong mechanism > + * to select one ring */ > + mutex_lock(&dev->struct_mutex); > + > + if (dual == 1 || (dual != 2 && > + dev_priv->mm.bsd_ring_dispatch_index == 0)) { > + ring_id = VCS; > + dev_priv->mm.bsd_ring_dispatch_index = 1; > + } else { > + ring_id = VCS2; > + dev_priv->mm.bsd_ring_dispatch_index = 0; > } > + > + file_priv->bsd_ring = &dev_priv->ring[ring_id]; > + mutex_unlock(&dev->struct_mutex); > + > + WARN(dual, "Forcibly trying to use only one bsd ring. Using: %s\n", > + file_priv->bsd_ring->name); Don't warn if this is valid module parameter people can use. > + return ring_id; > } > > static struct drm_i915_gem_object * > diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c > index 8145729..d4871c8 100644 > --- a/drivers/gpu/drm/i915/i915_params.c > +++ b/drivers/gpu/drm/i915/i915_params.c > @@ -29,6 +29,7 @@ struct i915_params i915 __read_mostly = { > .panel_ignore_lid = 1, > .powersave = 1, > .semaphores = -1, > + .dual_bsd_ring = 0, > .lvds_downclock = 0, > .lvds_channel_mode = 0, > .panel_use_ssc = -1, > @@ -70,6 +71,11 @@ MODULE_PARM_DESC(semaphores, > "Use semaphores for inter-ring sync " > "(default: -1 (use per-chip defaults))"); > > +module_param_named(dual_bsd_ring, i915.dual_bsd_ring, int, 0600); > +MODULE_PARM_DESC(dual_bsd_ring, > + "Specify bds rings for VCS when there are multiple VCSs available." > + "(0=All available bsd rings [default], 1=only VCS1, 2=only VCS2)"); > + It looks like life would be a lot easier if you did 0 = VCS 1 = VCS2 2 = BOTH > module_param_named(enable_rc6, i915.enable_rc6, int, 0400); > MODULE_PARM_DESC(enable_rc6, > "Enable power-saving render C-state 6. " Can't spot anything wrong, but again, I don't think the patch is worth merging unless we can find a good use case.
On Mon, 2014-06-30 at 09:51 -0700, Rodrigo Vivi wrote: > On Broadwell GT3 we have 2 Video Command Streamers (VCS), > but userspace has no control when using VCS1 or VCS2. So we cannot test, > validate or debug specific changes or workaround that might affect only > one or another ring. So this patch introduces a mechanism to avoid the > ping-pong selection and use one specific ring given at boot time. Hi, rodrigo Could you use a mechanism to specify the ring at runtime ? If so, it is flexible for us to use VCS ? Thanks Haihao > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > --- > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 34 ++++++++++++++++++------------ > drivers/gpu/drm/i915/i915_params.c | 6 ++++++ > 3 files changed, 27 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 8cea596..7b6614f 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -2069,6 +2069,7 @@ struct i915_params { > int panel_ignore_lid; > unsigned int powersave; > int semaphores; > + int dual_bsd_ring; > unsigned int lvds_downclock; > int lvds_channel_mode; > int panel_use_ssc; > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > index d815ef5..09f350e 100644 > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > @@ -1035,26 +1035,32 @@ static int gen8_dispatch_bsd_ring(struct drm_device *dev, > { > struct drm_i915_private *dev_priv = dev->dev_private; > struct drm_i915_file_private *file_priv = file->driver_priv; > + int ring_id; > + int dual = i915.dual_bsd_ring; > > /* Check whether the file_priv is using one ring */ > if (file_priv->bsd_ring) > return file_priv->bsd_ring->id; > - else { > - /* If no, use the ping-pong mechanism to select one ring */ > - int ring_id; > > - mutex_lock(&dev->struct_mutex); > - if (dev_priv->mm.bsd_ring_dispatch_index == 0) { > - ring_id = VCS; > - dev_priv->mm.bsd_ring_dispatch_index = 1; > - } else { > - ring_id = VCS2; > - dev_priv->mm.bsd_ring_dispatch_index = 0; > - } > - file_priv->bsd_ring = &dev_priv->ring[ring_id]; > - mutex_unlock(&dev->struct_mutex); > - return ring_id; > + /* If no, use the parameter defined or ping-pong mechanism > + * to select one ring */ > + mutex_lock(&dev->struct_mutex); > + > + if (dual == 1 || (dual != 2 && > + dev_priv->mm.bsd_ring_dispatch_index == 0)) { > + ring_id = VCS; > + dev_priv->mm.bsd_ring_dispatch_index = 1; > + } else { > + ring_id = VCS2; > + dev_priv->mm.bsd_ring_dispatch_index = 0; > } > + > + file_priv->bsd_ring = &dev_priv->ring[ring_id]; > + mutex_unlock(&dev->struct_mutex); > + > + WARN(dual, "Forcibly trying to use only one bsd ring. Using: %s\n", > + file_priv->bsd_ring->name); > + return ring_id; > } > > static struct drm_i915_gem_object * > diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c > index 8145729..d4871c8 100644 > --- a/drivers/gpu/drm/i915/i915_params.c > +++ b/drivers/gpu/drm/i915/i915_params.c > @@ -29,6 +29,7 @@ struct i915_params i915 __read_mostly = { > .panel_ignore_lid = 1, > .powersave = 1, > .semaphores = -1, > + .dual_bsd_ring = 0, > .lvds_downclock = 0, > .lvds_channel_mode = 0, > .panel_use_ssc = -1, > @@ -70,6 +71,11 @@ MODULE_PARM_DESC(semaphores, > "Use semaphores for inter-ring sync " > "(default: -1 (use per-chip defaults))"); > > +module_param_named(dual_bsd_ring, i915.dual_bsd_ring, int, 0600); > +MODULE_PARM_DESC(dual_bsd_ring, > + "Specify bds rings for VCS when there are multiple VCSs available." > + "(0=All available bsd rings [default], 1=only VCS1, 2=only VCS2)"); > + > module_param_named(enable_rc6, i915.enable_rc6, int, 0400); > MODULE_PARM_DESC(enable_rc6, > "Enable power-saving render C-state 6. "
On Mon, 2014-06-30 at 10:51 -0600, Rodrigo Vivi wrote: > On Broadwell GT3 we have 2 Video Command Streamers (VCS), > but userspace has no control when using VCS1 or VCS2. So we cannot test, > validate or debug specific changes or workaround that might affect only > one or another ring. So this patch introduces a mechanism to avoid the > ping-pong selection and use one specific ring given at boot time. If it is mainly used for the test/validation, can we add one override flag so that the user-space app can explicitly declare which BSD ring is used to dispatch the corresponding BSD commands? In such case it will force to dispatch the corresponding commands on the ring passed by user-application. At the same time this patch is not helpful under the following scenario. For example: One application hopes to use the BSD Ring 0 while another application hopes to use the BSD ring 1. > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > --- > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 34 ++++++++++++++++++------------ > drivers/gpu/drm/i915/i915_params.c | 6 ++++++ > 3 files changed, 27 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 8cea596..7b6614f 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -2069,6 +2069,7 @@ struct i915_params { > int panel_ignore_lid; > unsigned int powersave; > int semaphores; > + int dual_bsd_ring; > unsigned int lvds_downclock; > int lvds_channel_mode; > int panel_use_ssc; > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > index d815ef5..09f350e 100644 > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > @@ -1035,26 +1035,32 @@ static int gen8_dispatch_bsd_ring(struct drm_device *dev, > { > struct drm_i915_private *dev_priv = dev->dev_private; > struct drm_i915_file_private *file_priv = file->driver_priv; > + int ring_id; > + int dual = i915.dual_bsd_ring; > > /* Check whether the file_priv is using one ring */ > if (file_priv->bsd_ring) > return file_priv->bsd_ring->id; > - else { > - /* If no, use the ping-pong mechanism to select one ring */ > - int ring_id; > > - mutex_lock(&dev->struct_mutex); > - if (dev_priv->mm.bsd_ring_dispatch_index == 0) { > - ring_id = VCS; > - dev_priv->mm.bsd_ring_dispatch_index = 1; > - } else { > - ring_id = VCS2; > - dev_priv->mm.bsd_ring_dispatch_index = 0; > - } > - file_priv->bsd_ring = &dev_priv->ring[ring_id]; > - mutex_unlock(&dev->struct_mutex); > - return ring_id; > + /* If no, use the parameter defined or ping-pong mechanism > + * to select one ring */ > + mutex_lock(&dev->struct_mutex); > + > + if (dual == 1 || (dual != 2 && > + dev_priv->mm.bsd_ring_dispatch_index == 0)) { > + ring_id = VCS; > + dev_priv->mm.bsd_ring_dispatch_index = 1; > + } else { > + ring_id = VCS2; > + dev_priv->mm.bsd_ring_dispatch_index = 0; > } > + > + file_priv->bsd_ring = &dev_priv->ring[ring_id]; > + mutex_unlock(&dev->struct_mutex); > + > + WARN(dual, "Forcibly trying to use only one bsd ring. Using: %s\n", > + file_priv->bsd_ring->name); > + return ring_id; > } > > static struct drm_i915_gem_object * > diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c > index 8145729..d4871c8 100644 > --- a/drivers/gpu/drm/i915/i915_params.c > +++ b/drivers/gpu/drm/i915/i915_params.c > @@ -29,6 +29,7 @@ struct i915_params i915 __read_mostly = { > .panel_ignore_lid = 1, > .powersave = 1, > .semaphores = -1, > + .dual_bsd_ring = 0, > .lvds_downclock = 0, > .lvds_channel_mode = 0, > .panel_use_ssc = -1, > @@ -70,6 +71,11 @@ MODULE_PARM_DESC(semaphores, > "Use semaphores for inter-ring sync " > "(default: -1 (use per-chip defaults))"); > > +module_param_named(dual_bsd_ring, i915.dual_bsd_ring, int, 0600); > +MODULE_PARM_DESC(dual_bsd_ring, > + "Specify bds rings for VCS when there are multiple VCSs available." > + "(0=All available bsd rings [default], 1=only VCS1, 2=only VCS2)"); > + > module_param_named(enable_rc6, i915.enable_rc6, int, 0400); > MODULE_PARM_DESC(enable_rc6, > "Enable power-saving render C-state 6. "
It seems the flexibility on rings is more wanted and needed than I imagined. Please ignore this patch here... I liked both execution flag or debugfs, but exec flag would cover this case of different applications using different command streamers. With flags Would it be something like: Execution without flag = ping-pong Flag BSD1 use only VCS1 Flag BSD2 use only VCS2 Haihao, what do you think? With debugfs would be something like i195_dual_bsd_ring file with 3 options: all bsd1 bsd2 Thanks, Rodrigo. -----Original Message----- From: Zhao, Yakui Sent: Monday, June 30, 2014 6:37 PM To: Vivi, Rodrigo Cc: intel-gfx@lists.freedesktop.org Subject: Re: [Intel-gfx] [PATCH 2/3] drm/i915: Introduce dual_bsd_ring parameter. On Mon, 2014-06-30 at 10:51 -0600, Rodrigo Vivi wrote: > On Broadwell GT3 we have 2 Video Command Streamers (VCS), but > userspace has no control when using VCS1 or VCS2. So we cannot test, > validate or debug specific changes or workaround that might affect > only one or another ring. So this patch introduces a mechanism to > avoid the ping-pong selection and use one specific ring given at boot time. If it is mainly used for the test/validation, can we add one override flag so that the user-space app can explicitly declare which BSD ring is used to dispatch the corresponding BSD commands? In such case it will force to dispatch the corresponding commands on the ring passed by user-application. At the same time this patch is not helpful under the following scenario. For example: One application hopes to use the BSD Ring 0 while another application hopes to use the BSD ring 1. > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > --- > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 34 ++++++++++++++++++------------ > drivers/gpu/drm/i915/i915_params.c | 6 ++++++ > 3 files changed, 27 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h > b/drivers/gpu/drm/i915/i915_drv.h index 8cea596..7b6614f 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -2069,6 +2069,7 @@ struct i915_params { > int panel_ignore_lid; > unsigned int powersave; > int semaphores; > + int dual_bsd_ring; > unsigned int lvds_downclock; > int lvds_channel_mode; > int panel_use_ssc; > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > index d815ef5..09f350e 100644 > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > @@ -1035,26 +1035,32 @@ static int gen8_dispatch_bsd_ring(struct > drm_device *dev, { > struct drm_i915_private *dev_priv = dev->dev_private; > struct drm_i915_file_private *file_priv = file->driver_priv; > + int ring_id; > + int dual = i915.dual_bsd_ring; > > /* Check whether the file_priv is using one ring */ > if (file_priv->bsd_ring) > return file_priv->bsd_ring->id; > - else { > - /* If no, use the ping-pong mechanism to select one ring */ > - int ring_id; > > - mutex_lock(&dev->struct_mutex); > - if (dev_priv->mm.bsd_ring_dispatch_index == 0) { > - ring_id = VCS; > - dev_priv->mm.bsd_ring_dispatch_index = 1; > - } else { > - ring_id = VCS2; > - dev_priv->mm.bsd_ring_dispatch_index = 0; > - } > - file_priv->bsd_ring = &dev_priv->ring[ring_id]; > - mutex_unlock(&dev->struct_mutex); > - return ring_id; > + /* If no, use the parameter defined or ping-pong mechanism > + * to select one ring */ > + mutex_lock(&dev->struct_mutex); > + > + if (dual == 1 || (dual != 2 && > + dev_priv->mm.bsd_ring_dispatch_index == 0)) { > + ring_id = VCS; > + dev_priv->mm.bsd_ring_dispatch_index = 1; > + } else { > + ring_id = VCS2; > + dev_priv->mm.bsd_ring_dispatch_index = 0; > } > + > + file_priv->bsd_ring = &dev_priv->ring[ring_id]; > + mutex_unlock(&dev->struct_mutex); > + > + WARN(dual, "Forcibly trying to use only one bsd ring. Using: %s\n", > + file_priv->bsd_ring->name); > + return ring_id; > } > > static struct drm_i915_gem_object * > diff --git a/drivers/gpu/drm/i915/i915_params.c > b/drivers/gpu/drm/i915/i915_params.c > index 8145729..d4871c8 100644 > --- a/drivers/gpu/drm/i915/i915_params.c > +++ b/drivers/gpu/drm/i915/i915_params.c > @@ -29,6 +29,7 @@ struct i915_params i915 __read_mostly = { > .panel_ignore_lid = 1, > .powersave = 1, > .semaphores = -1, > + .dual_bsd_ring = 0, > .lvds_downclock = 0, > .lvds_channel_mode = 0, > .panel_use_ssc = -1, > @@ -70,6 +71,11 @@ MODULE_PARM_DESC(semaphores, > "Use semaphores for inter-ring sync " > "(default: -1 (use per-chip defaults))"); > > +module_param_named(dual_bsd_ring, i915.dual_bsd_ring, int, 0600); > +MODULE_PARM_DESC(dual_bsd_ring, > + "Specify bds rings for VCS when there are multiple VCSs available." > + "(0=All available bsd rings [default], 1=only VCS1, 2=only VCS2)"); > + > module_param_named(enable_rc6, i915.enable_rc6, int, 0400); > MODULE_PARM_DESC(enable_rc6, > "Enable power-saving render C-state 6. "
On Tue, 2014-07-01 at 09:26 -0600, Vivi, Rodrigo wrote: > It seems the flexibility on rings is more wanted and needed than I imagined. > Please ignore this patch here... > > I liked both execution flag or debugfs, but exec flag would cover this case of different applications using different command streamers. > > With flags Would it be something like: > Execution without flag = ping-pong > Flag BSD1 use only VCS1 > Flag BSD2 use only VCS2 > IMO the execution flag looks reasonable. It can cover the flexibility of different applications. In such case it can determine which ring is used to dispatch command at runtime. > Haihao, what do you think? > > With debugfs would be something like i195_dual_bsd_ring file with 3 options: all bsd1 bsd2 > > Thanks, > Rodrigo. > > -----Original Message----- > From: Zhao, Yakui > Sent: Monday, June 30, 2014 6:37 PM > To: Vivi, Rodrigo > Cc: intel-gfx@lists.freedesktop.org > Subject: Re: [Intel-gfx] [PATCH 2/3] drm/i915: Introduce dual_bsd_ring parameter. > > On Mon, 2014-06-30 at 10:51 -0600, Rodrigo Vivi wrote: > > On Broadwell GT3 we have 2 Video Command Streamers (VCS), but > > userspace has no control when using VCS1 or VCS2. So we cannot test, > > validate or debug specific changes or workaround that might affect > > only one or another ring. So this patch introduces a mechanism to > > avoid the ping-pong selection and use one specific ring given at boot time. > > If it is mainly used for the test/validation, can we add one override flag so that the user-space app can explicitly declare which BSD ring is used to dispatch the corresponding BSD commands? In such case it will force to dispatch the corresponding commands on the ring passed by user-application. > > At the same time this patch is not helpful under the following scenario. For example: One application hopes to use the BSD Ring 0 while another application hopes to use the BSD ring 1. > > > > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > > --- > > drivers/gpu/drm/i915/i915_drv.h | 1 + > > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 34 ++++++++++++++++++------------ > > drivers/gpu/drm/i915/i915_params.c | 6 ++++++ > > 3 files changed, 27 insertions(+), 14 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h > > b/drivers/gpu/drm/i915/i915_drv.h index 8cea596..7b6614f 100644 > > --- a/drivers/gpu/drm/i915/i915_drv.h > > +++ b/drivers/gpu/drm/i915/i915_drv.h > > @@ -2069,6 +2069,7 @@ struct i915_params { > > int panel_ignore_lid; > > unsigned int powersave; > > int semaphores; > > + int dual_bsd_ring; > > unsigned int lvds_downclock; > > int lvds_channel_mode; > > int panel_use_ssc; > > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > index d815ef5..09f350e 100644 > > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > @@ -1035,26 +1035,32 @@ static int gen8_dispatch_bsd_ring(struct > > drm_device *dev, { > > struct drm_i915_private *dev_priv = dev->dev_private; > > struct drm_i915_file_private *file_priv = file->driver_priv; > > + int ring_id; > > + int dual = i915.dual_bsd_ring; > > > > /* Check whether the file_priv is using one ring */ > > if (file_priv->bsd_ring) > > return file_priv->bsd_ring->id; > > - else { > > - /* If no, use the ping-pong mechanism to select one ring */ > > - int ring_id; > > > > - mutex_lock(&dev->struct_mutex); > > - if (dev_priv->mm.bsd_ring_dispatch_index == 0) { > > - ring_id = VCS; > > - dev_priv->mm.bsd_ring_dispatch_index = 1; > > - } else { > > - ring_id = VCS2; > > - dev_priv->mm.bsd_ring_dispatch_index = 0; > > - } > > - file_priv->bsd_ring = &dev_priv->ring[ring_id]; > > - mutex_unlock(&dev->struct_mutex); > > - return ring_id; > > + /* If no, use the parameter defined or ping-pong mechanism > > + * to select one ring */ > > + mutex_lock(&dev->struct_mutex); > > + > > + if (dual == 1 || (dual != 2 && > > + dev_priv->mm.bsd_ring_dispatch_index == 0)) { > > + ring_id = VCS; > > + dev_priv->mm.bsd_ring_dispatch_index = 1; > > + } else { > > + ring_id = VCS2; > > + dev_priv->mm.bsd_ring_dispatch_index = 0; > > } > > + > > + file_priv->bsd_ring = &dev_priv->ring[ring_id]; > > + mutex_unlock(&dev->struct_mutex); > > + > > + WARN(dual, "Forcibly trying to use only one bsd ring. Using: %s\n", > > + file_priv->bsd_ring->name); > > + return ring_id; > > } > > > > static struct drm_i915_gem_object * > > diff --git a/drivers/gpu/drm/i915/i915_params.c > > b/drivers/gpu/drm/i915/i915_params.c > > index 8145729..d4871c8 100644 > > --- a/drivers/gpu/drm/i915/i915_params.c > > +++ b/drivers/gpu/drm/i915/i915_params.c > > @@ -29,6 +29,7 @@ struct i915_params i915 __read_mostly = { > > .panel_ignore_lid = 1, > > .powersave = 1, > > .semaphores = -1, > > + .dual_bsd_ring = 0, > > .lvds_downclock = 0, > > .lvds_channel_mode = 0, > > .panel_use_ssc = -1, > > @@ -70,6 +71,11 @@ MODULE_PARM_DESC(semaphores, > > "Use semaphores for inter-ring sync " > > "(default: -1 (use per-chip defaults))"); > > > > +module_param_named(dual_bsd_ring, i915.dual_bsd_ring, int, 0600); > > +MODULE_PARM_DESC(dual_bsd_ring, > > + "Specify bds rings for VCS when there are multiple VCSs available." > > + "(0=All available bsd rings [default], 1=only VCS1, 2=only VCS2)"); > > + > > module_param_named(enable_rc6, i915.enable_rc6, int, 0400); > > MODULE_PARM_DESC(enable_rc6, > > "Enable power-saving render C-state 6. " > >
On Wed, 2014-07-02 at 07:52 +0800, Zhao, Yakui wrote: > On Tue, 2014-07-01 at 09:26 -0600, Vivi, Rodrigo wrote: > > It seems the flexibility on rings is more wanted and needed than I imagined. > > Please ignore this patch here... > > > > I liked both execution flag or debugfs, but exec flag would cover this case of different applications using different command streamers. > > > > With flags Would it be something like: > > Execution without flag = ping-pong > > Flag BSD1 use only VCS1 > > Flag BSD2 use only VCS2 > > > > IMO the execution flag looks reasonable. It can cover the flexibility of > different applications. In such case it can determine which ring is used > to dispatch command at runtime. > I prefer the execution flag too. Thanks Haihao > > Haihao, what do you think? > > > > With debugfs would be something like i195_dual_bsd_ring file with 3 options: all bsd1 bsd2 > > > > Thanks, > > Rodrigo. > > > > -----Original Message----- > > From: Zhao, Yakui > > Sent: Monday, June 30, 2014 6:37 PM > > To: Vivi, Rodrigo > > Cc: intel-gfx@lists.freedesktop.org > > Subject: Re: [Intel-gfx] [PATCH 2/3] drm/i915: Introduce dual_bsd_ring parameter. > > > > On Mon, 2014-06-30 at 10:51 -0600, Rodrigo Vivi wrote: > > > On Broadwell GT3 we have 2 Video Command Streamers (VCS), but > > > userspace has no control when using VCS1 or VCS2. So we cannot test, > > > validate or debug specific changes or workaround that might affect > > > only one or another ring. So this patch introduces a mechanism to > > > avoid the ping-pong selection and use one specific ring given at boot time. > > > > If it is mainly used for the test/validation, can we add one override flag so that the user-space app can explicitly declare which BSD ring is used to dispatch the corresponding BSD commands? In such case it will force to dispatch the corresponding commands on the ring passed by user-application. > > > > At the same time this patch is not helpful under the following scenario. For example: One application hopes to use the BSD Ring 0 while another application hopes to use the BSD ring 1. > > > > > > > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > > > --- > > > drivers/gpu/drm/i915/i915_drv.h | 1 + > > > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 34 ++++++++++++++++++------------ > > > drivers/gpu/drm/i915/i915_params.c | 6 ++++++ > > > 3 files changed, 27 insertions(+), 14 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/i915/i915_drv.h > > > b/drivers/gpu/drm/i915/i915_drv.h index 8cea596..7b6614f 100644 > > > --- a/drivers/gpu/drm/i915/i915_drv.h > > > +++ b/drivers/gpu/drm/i915/i915_drv.h > > > @@ -2069,6 +2069,7 @@ struct i915_params { > > > int panel_ignore_lid; > > > unsigned int powersave; > > > int semaphores; > > > + int dual_bsd_ring; > > > unsigned int lvds_downclock; > > > int lvds_channel_mode; > > > int panel_use_ssc; > > > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > > b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > > index d815ef5..09f350e 100644 > > > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > > > @@ -1035,26 +1035,32 @@ static int gen8_dispatch_bsd_ring(struct > > > drm_device *dev, { > > > struct drm_i915_private *dev_priv = dev->dev_private; > > > struct drm_i915_file_private *file_priv = file->driver_priv; > > > + int ring_id; > > > + int dual = i915.dual_bsd_ring; > > > > > > /* Check whether the file_priv is using one ring */ > > > if (file_priv->bsd_ring) > > > return file_priv->bsd_ring->id; > > > - else { > > > - /* If no, use the ping-pong mechanism to select one ring */ > > > - int ring_id; > > > > > > - mutex_lock(&dev->struct_mutex); > > > - if (dev_priv->mm.bsd_ring_dispatch_index == 0) { > > > - ring_id = VCS; > > > - dev_priv->mm.bsd_ring_dispatch_index = 1; > > > - } else { > > > - ring_id = VCS2; > > > - dev_priv->mm.bsd_ring_dispatch_index = 0; > > > - } > > > - file_priv->bsd_ring = &dev_priv->ring[ring_id]; > > > - mutex_unlock(&dev->struct_mutex); > > > - return ring_id; > > > + /* If no, use the parameter defined or ping-pong mechanism > > > + * to select one ring */ > > > + mutex_lock(&dev->struct_mutex); > > > + > > > + if (dual == 1 || (dual != 2 && > > > + dev_priv->mm.bsd_ring_dispatch_index == 0)) { > > > + ring_id = VCS; > > > + dev_priv->mm.bsd_ring_dispatch_index = 1; > > > + } else { > > > + ring_id = VCS2; > > > + dev_priv->mm.bsd_ring_dispatch_index = 0; > > > } > > > + > > > + file_priv->bsd_ring = &dev_priv->ring[ring_id]; > > > + mutex_unlock(&dev->struct_mutex); > > > + > > > + WARN(dual, "Forcibly trying to use only one bsd ring. Using: %s\n", > > > + file_priv->bsd_ring->name); > > > + return ring_id; > > > } > > > > > > static struct drm_i915_gem_object * > > > diff --git a/drivers/gpu/drm/i915/i915_params.c > > > b/drivers/gpu/drm/i915/i915_params.c > > > index 8145729..d4871c8 100644 > > > --- a/drivers/gpu/drm/i915/i915_params.c > > > +++ b/drivers/gpu/drm/i915/i915_params.c > > > @@ -29,6 +29,7 @@ struct i915_params i915 __read_mostly = { > > > .panel_ignore_lid = 1, > > > .powersave = 1, > > > .semaphores = -1, > > > + .dual_bsd_ring = 0, > > > .lvds_downclock = 0, > > > .lvds_channel_mode = 0, > > > .panel_use_ssc = -1, > > > @@ -70,6 +71,11 @@ MODULE_PARM_DESC(semaphores, > > > "Use semaphores for inter-ring sync " > > > "(default: -1 (use per-chip defaults))"); > > > > > > +module_param_named(dual_bsd_ring, i915.dual_bsd_ring, int, 0600); > > > +MODULE_PARM_DESC(dual_bsd_ring, > > > + "Specify bds rings for VCS when there are multiple VCSs available." > > > + "(0=All available bsd rings [default], 1=only VCS1, 2=only VCS2)"); > > > + > > > module_param_named(enable_rc6, i915.enable_rc6, int, 0400); > > > MODULE_PARM_DESC(enable_rc6, > > > "Enable power-saving render C-state 6. " > > > > > >
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 8cea596..7b6614f 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2069,6 +2069,7 @@ struct i915_params { int panel_ignore_lid; unsigned int powersave; int semaphores; + int dual_bsd_ring; unsigned int lvds_downclock; int lvds_channel_mode; int panel_use_ssc; diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index d815ef5..09f350e 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -1035,26 +1035,32 @@ static int gen8_dispatch_bsd_ring(struct drm_device *dev, { struct drm_i915_private *dev_priv = dev->dev_private; struct drm_i915_file_private *file_priv = file->driver_priv; + int ring_id; + int dual = i915.dual_bsd_ring; /* Check whether the file_priv is using one ring */ if (file_priv->bsd_ring) return file_priv->bsd_ring->id; - else { - /* If no, use the ping-pong mechanism to select one ring */ - int ring_id; - mutex_lock(&dev->struct_mutex); - if (dev_priv->mm.bsd_ring_dispatch_index == 0) { - ring_id = VCS; - dev_priv->mm.bsd_ring_dispatch_index = 1; - } else { - ring_id = VCS2; - dev_priv->mm.bsd_ring_dispatch_index = 0; - } - file_priv->bsd_ring = &dev_priv->ring[ring_id]; - mutex_unlock(&dev->struct_mutex); - return ring_id; + /* If no, use the parameter defined or ping-pong mechanism + * to select one ring */ + mutex_lock(&dev->struct_mutex); + + if (dual == 1 || (dual != 2 && + dev_priv->mm.bsd_ring_dispatch_index == 0)) { + ring_id = VCS; + dev_priv->mm.bsd_ring_dispatch_index = 1; + } else { + ring_id = VCS2; + dev_priv->mm.bsd_ring_dispatch_index = 0; } + + file_priv->bsd_ring = &dev_priv->ring[ring_id]; + mutex_unlock(&dev->struct_mutex); + + WARN(dual, "Forcibly trying to use only one bsd ring. Using: %s\n", + file_priv->bsd_ring->name); + return ring_id; } static struct drm_i915_gem_object * diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 8145729..d4871c8 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -29,6 +29,7 @@ struct i915_params i915 __read_mostly = { .panel_ignore_lid = 1, .powersave = 1, .semaphores = -1, + .dual_bsd_ring = 0, .lvds_downclock = 0, .lvds_channel_mode = 0, .panel_use_ssc = -1, @@ -70,6 +71,11 @@ MODULE_PARM_DESC(semaphores, "Use semaphores for inter-ring sync " "(default: -1 (use per-chip defaults))"); +module_param_named(dual_bsd_ring, i915.dual_bsd_ring, int, 0600); +MODULE_PARM_DESC(dual_bsd_ring, + "Specify bds rings for VCS when there are multiple VCSs available." + "(0=All available bsd rings [default], 1=only VCS1, 2=only VCS2)"); + module_param_named(enable_rc6, i915.enable_rc6, int, 0400); MODULE_PARM_DESC(enable_rc6, "Enable power-saving render C-state 6. "
On Broadwell GT3 we have 2 Video Command Streamers (VCS), but userspace has no control when using VCS1 or VCS2. So we cannot test, validate or debug specific changes or workaround that might affect only one or another ring. So this patch introduces a mechanism to avoid the ping-pong selection and use one specific ring given at boot time. Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com> --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_gem_execbuffer.c | 34 ++++++++++++++++++------------ drivers/gpu/drm/i915/i915_params.c | 6 ++++++ 3 files changed, 27 insertions(+), 14 deletions(-)