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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/gpu/drm/i915/gem/i915_gem_throttle.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/i915/gem/i915_gem_throttle.c')
-rw-r--r-- | drivers/gpu/drm/i915/gem/i915_gem_throttle.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_throttle.c b/drivers/gpu/drm/i915/gem/i915_gem_throttle.c new file mode 100644 index 0000000000..af85d0c281 --- /dev/null +++ b/drivers/gpu/drm/i915/gem/i915_gem_throttle.c @@ -0,0 +1,102 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2014-2016 Intel Corporation + */ + +#include <linux/jiffies.h> + +#include <drm/drm_file.h> + +#include "i915_drv.h" +#include "i915_file_private.h" +#include "i915_gem_context.h" +#include "i915_gem_ioctls.h" +#include "i915_gem_object.h" + +/* + * 20ms is a fairly arbitrary limit (greater than the average frame time) + * chosen to prevent the CPU getting more than a frame ahead of the GPU + * (when using lax throttling for the frontbuffer). We also use it to + * offer free GPU waitboosts for severely congested workloads. + */ +#define DRM_I915_THROTTLE_JIFFIES msecs_to_jiffies(20) + +/* + * Throttle our rendering by waiting until the ring has completed our requests + * emitted over 20 msec ago. + * + * Note that if we were to use the current jiffies each time around the loop, + * we wouldn't escape the function with any frames outstanding if the time to + * render a frame was over 20ms. + * + * This should get us reasonable parallelism between CPU and GPU but also + * relatively low latency when blocking on a particular request to finish. + */ +int +i915_gem_throttle_ioctl(struct drm_device *dev, void *data, + struct drm_file *file) +{ + const unsigned long recent_enough = jiffies - DRM_I915_THROTTLE_JIFFIES; + struct drm_i915_file_private *file_priv = file->driver_priv; + struct drm_i915_private *i915 = to_i915(dev); + struct i915_gem_context *ctx; + unsigned long idx; + long ret; + + /* ABI: return -EIO if already wedged */ + ret = intel_gt_terminally_wedged(to_gt(i915)); + if (ret) + return ret; + + rcu_read_lock(); + xa_for_each(&file_priv->context_xa, idx, ctx) { + struct i915_gem_engines_iter it; + struct intel_context *ce; + + if (!kref_get_unless_zero(&ctx->ref)) + continue; + rcu_read_unlock(); + + for_each_gem_engine(ce, + i915_gem_context_lock_engines(ctx), + it) { + struct i915_request *rq, *target = NULL; + + if (!ce->timeline) + continue; + + mutex_lock(&ce->timeline->mutex); + list_for_each_entry_reverse(rq, + &ce->timeline->requests, + link) { + if (i915_request_completed(rq)) + break; + + if (time_after(rq->emitted_jiffies, + recent_enough)) + continue; + + target = i915_request_get(rq); + break; + } + mutex_unlock(&ce->timeline->mutex); + if (!target) + continue; + + ret = i915_request_wait(target, + I915_WAIT_INTERRUPTIBLE, + MAX_SCHEDULE_TIMEOUT); + i915_request_put(target); + if (ret < 0) + break; + } + i915_gem_context_unlock_engines(ctx); + i915_gem_context_put(ctx); + + rcu_read_lock(); + } + rcu_read_unlock(); + + return ret < 0 ? ret : 0; +} |