From 5d983b09f87b27e6474f21f6d04d38f11550149c Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Wed, 24 Jul 2013 20:18:20 -0500
Subject: [PATCH] Fix lmem usage estimate in scan, parametrize scan test
---
pyopencl/scan.py | 31 +++++++++++++++++++++-------
test/test_algorithm.py | 47 +++++++++++++++++++-----------------------
2 files changed, 44 insertions(+), 34 deletions(-)
diff --git a/pyopencl/scan.py b/pyopencl/scan.py
index ae380ff2..41dd7912 100644
--- a/pyopencl/scan.py
+++ b/pyopencl/scan.py
@@ -143,7 +143,7 @@ void ${name_prefix}_scan_intervals(
)
{
// index K in first dimension used for carry storage
- %if scan_dtype.itemsize > 4 and scan_dtype.itemsize % 8 == 0 and is_gpu:
+ %if use_bank_conflict_avoidance:
// Avoid bank conflicts by adding a single 32-bit value to the size of
// the scan type.
struct __attribute__ ((__packed__)) wrapped_scan_type
@@ -1064,7 +1064,10 @@ class GenericScanKernel(_GenericScanKernelBase):
dev.local_mem_size
for dev in self.devices)
- if self.devices[0].type == cl.device_type.CPU:
+ is_cpu = self.devices[0].type & cl.device_type.CPU
+ is_gpu = self.devices[0].type & cl.device_type.GPU
+
+ if is_cpu:
# (about the widest vector a CPU can support, also taking
# into account that CPUs don't hide latency by large work groups
max_scan_wg_size = 16
@@ -1073,6 +1076,9 @@ class GenericScanKernel(_GenericScanKernelBase):
max_scan_wg_size = min(dev.max_work_group_size for dev in self.devices)
wg_size_multiples = 64
+ use_bank_conflict_avoidance = (
+ self.dtype.itemsize > 4 and self.dtype.itemsize % 8 == 0 and is_gpu)
+
# k_group_size should be a power of two because of in-kernel
# division by that number.
@@ -1082,11 +1088,12 @@ class GenericScanKernel(_GenericScanKernelBase):
wg_size_multiples):
k_group_size = 2**k_exp
- lmem_use = self.get_local_mem_use(wg_size, k_group_size)
+ lmem_use = self.get_local_mem_use(wg_size, k_group_size,
+ use_bank_conflict_avoidance)
if lmem_use + 256 <= avail_local_mem:
solutions.append((wg_size*k_group_size, k_group_size, wg_size))
- if self.devices[0].type & cl.device_type.GPU:
+ if is_gpu:
from pytools import any
for wg_size_floor in [256, 192, 128]:
have_sol_above_floor = any(wg_size >= wg_size_floor
@@ -1109,7 +1116,8 @@ class GenericScanKernel(_GenericScanKernelBase):
input_fetch_exprs=self.input_fetch_exprs,
is_first_level=True,
store_segment_start_flags=self.store_segment_start_flags,
- k_group_size=k_group_size)
+ k_group_size=k_group_size,
+ use_bank_conflict_avoidance=use_bank_conflict_avoidance)
# Will this device actually let us execute this kernel
# at the desired work group size? Building it is the
@@ -1164,6 +1172,7 @@ class GenericScanKernel(_GenericScanKernelBase):
is_first_level=False,
store_segment_start_flags=False,
k_group_size=k_group_size,
+ use_bank_conflict_avoidance=use_bank_conflict_avoidance,
**second_level_build_kwargs)
# }}}
@@ -1202,7 +1211,7 @@ class GenericScanKernel(_GenericScanKernelBase):
# {{{ scan kernel build/properties
- def get_local_mem_use(self, k_group_size, wg_size):
+ def get_local_mem_use(self, k_group_size, wg_size, use_bank_conflict_avoidance):
arg_dtypes = {}
for arg in self.parsed_args:
arg_dtypes[arg.name] = arg.dtype
@@ -1211,9 +1220,13 @@ class GenericScanKernel(_GenericScanKernelBase):
for name, arg_name, ife_offset in self.input_fetch_exprs:
fetch_expr_offsets.setdefault(arg_name, set()).add(ife_offset)
+ itemsize = self.dtype.itemsize
+ if use_bank_conflict_avoidance:
+ itemsize += 4
+
return (
# ldata
- self.dtype.itemsize*(k_group_size+1)*(wg_size+1)
+ itemsize*(k_group_size+1)*(wg_size+1)
# l_segment_start_flags
+ k_group_size*wg_size
@@ -1228,7 +1241,8 @@ class GenericScanKernel(_GenericScanKernelBase):
def build_scan_kernel(self, max_wg_size, arguments, input_expr,
is_segment_start_expr, input_fetch_exprs, is_first_level,
- store_segment_start_flags, k_group_size):
+ store_segment_start_flags, k_group_size,
+ use_bank_conflict_avoidance):
scalar_arg_dtypes = get_arg_list_scalar_arg_dtypes(arguments)
# Empirically found on Nv hardware: no need to be bigger than this size
@@ -1245,6 +1259,7 @@ class GenericScanKernel(_GenericScanKernelBase):
input_fetch_exprs=input_fetch_exprs,
is_first_level=is_first_level,
store_segment_start_flags=store_segment_start_flags,
+ use_bank_conflict_avoidance=use_bank_conflict_avoidance,
**self.code_variables))
prg = cl.Program(self.context, scan_src).build(self.options)
diff --git a/test/test_algorithm.py b/test/test_algorithm.py
index bcc687e2..7f0f9f4c 100644
--- a/test/test_algorithm.py
+++ b/test/test_algorithm.py
@@ -486,44 +486,39 @@ scan_test_counts = [
]
-def test_scan(ctx_factory):
+@pytest.mark.parametrize("dtype", [np.int32, np.int64])
+@pytest.mark.parametrize("scan_cls", [InclusiveScanKernel, ExclusiveScanKernel])
+def test_scan(ctx_factory, dtype, scan_cls):
from pytest import importorskip
importorskip("mako")
context = ctx_factory()
queue = cl.CommandQueue(context)
- from pyopencl.scan import InclusiveScanKernel, ExclusiveScanKernel
+ knl = scan_cls(context, dtype, "a+b", "0")
- dtype = np.int32
- for cls in [
- InclusiveScanKernel,
- ExclusiveScanKernel
- ]:
- knl = cls(context, dtype, "a+b", "0")
-
- for n in scan_test_counts:
- host_data = np.random.randint(0, 10, n).astype(dtype)
- dev_data = cl_array.to_device(queue, host_data)
+ for n in scan_test_counts:
+ host_data = np.random.randint(0, 10, n).astype(dtype)
+ dev_data = cl_array.to_device(queue, host_data)
- # /!\ fails on Nv GT2?? for some drivers
- assert (host_data == dev_data.get()).all()
+ # /!\ fails on Nv GT2?? for some drivers
+ assert (host_data == dev_data.get()).all()
- knl(dev_data)
+ knl(dev_data)
- desired_result = np.cumsum(host_data, axis=0)
- if cls is ExclusiveScanKernel:
- desired_result -= host_data
+ desired_result = np.cumsum(host_data, axis=0)
+ if scan_cls is ExclusiveScanKernel:
+ desired_result -= host_data
- is_ok = (dev_data.get() == desired_result).all()
- if 1 and not is_ok:
- print("something went wrong, summarizing error...")
- print(summarize_error(dev_data.get(), desired_result, host_data))
+ is_ok = (dev_data.get() == desired_result).all()
+ if 1 and not is_ok:
+ print("something went wrong, summarizing error...")
+ print(summarize_error(dev_data.get(), desired_result, host_data))
- print("n:%d %s worked:%s" % (n, cls, is_ok))
- assert is_ok
- from gc import collect
- collect()
+ print("dtype:%s n:%d %s worked:%s" % (dtype, n, scan_cls, is_ok))
+ assert is_ok
+ from gc import collect
+ collect()
def test_copy_if(ctx_factory):
--
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