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| author | Johan Alfvén <johan.alfven@arm.com> | 2022-12-06 11:16:19 +0100 |
|---|---|---|
| committer | Johan Alfvén <johan.alfven@arm.com> | 2022-12-08 11:04:07 +0100 |
| commit | 92689d5ad0dd19a3249e71dd0563731d4c6527c8 (patch) | |
| tree | 77c176d06d3f11191b3fc75b3d57be89d292a754 | |
| parent | db947e46755d8262710e734ccb2fb51ec725c844 (diff) | |
| download | ethos-u-vela-92689d5ad0dd19a3249e71dd0563731d4c6527c8.tar.gz | |
MLBEDSW-6716: Updates to estimate op SRAM usage
- The cascade builder estimates how much SRAM usage an operator
takes when calculating the cascades. If an elementwise operator
is included in a cascade the IFM2 will always be a constant/scalar
and the IFM2 will be in permanent memory and the size of the
IFM2 should not be included in the SRAM estimate.
- The scheduler did not take into account that IFM can be reused
for the OFM when calculating the op memory usage resulting in
a negative number for non-local memory usage. Corrected the
calculation and added assert to detect future problems.
Change-Id: Id7ec8fe1ec5560290f34579a7b9203a75067aba2
Signed-off-by: Johan Alfven <johan.alfven@arm.com>
| -rw-r--r-- | ethosu/vela/cascade_builder.py | 6 | ||||
| -rw-r--r-- | ethosu/vela/scheduler.py | 5 |
2 files changed, 9 insertions, 2 deletions
diff --git a/ethosu/vela/cascade_builder.py b/ethosu/vela/cascade_builder.py index 7baa3a83..ba210032 100644 --- a/ethosu/vela/cascade_builder.py +++ b/ethosu/vela/cascade_builder.py @@ -105,7 +105,11 @@ class CascadeBuilder: def _estimate_sram_usage(self, sched_op, cost) -> int: """Estimate the SRAM required for the Op if all FeatureMaps are in SRAM""" - ifm2_size = sched_op.ifm2_size_in_bytes() + if sched_op.parent_op.type.is_binary_elementwise_op(): + # ifm2 is scalar or constant and will always persist in permanent memory + ifm2_size = 0 + else: + ifm2_size = sched_op.ifm2_size_in_bytes() if sched_op.requires_full_ifm: ifm_size = sched_op.ifm_size_in_bytes() else: diff --git a/ethosu/vela/scheduler.py b/ethosu/vela/scheduler.py index 73eb8b42..c7d08fbb 100644 --- a/ethosu/vela/scheduler.py +++ b/ethosu/vela/scheduler.py @@ -57,6 +57,7 @@ from .nn_graph import Pass from .nn_graph import PassPlacement from .nn_graph import SchedulingStrategy from .nn_graph import Subgraph +from .live_range import ofm_can_reuse_ifm from .numeric_util import round_down from .numeric_util import round_up from .operation import NpuBlockType @@ -974,9 +975,11 @@ class Scheduler: op_mem_usage = 0 else: # Min schedule only have ifm and ofm in SRAM (no buffered weigth tensors) - op_mem_usage = sched_op.ifm_size_in_bytes() + sched_op.ofm_size_in_bytes() + ofm_size = 0 if ofm_can_reuse_ifm(sched_op) else sched_op.ofm_size_in_bytes() + op_mem_usage = sched_op.ifm_size_in_bytes() + ofm_size non_local_mem_usage[sched_op] = min_schedule.memory_snapshot[time_index] - op_mem_usage + assert non_local_mem_usage[sched_op] >= 0 # Crate cascades for Min schedule cascade_builder = CascadeBuilder(self.sched_ops, self.arch.is_spilling_enabled(), non_local_mem_usage) |