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Serialize GPU leases with per-accelerator locks

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Marek Lemańczyk committed 2025-09-20 18:19:21 +02:00
1 parent 2683dfcff1
commit abe695788b
6 files changed
+284 -182
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PerfectNumbers.Core/Gpu/MersenneNumberOrderGpuTester.cs
+43 -35
View File
@@ -10,7 +10,9 @@ public class MersenneNumberOrderGpuTester(GpuKernelType kernelType, bool useGpuO
public void Scan(ulong exponent, UInt128 twoP, bool lastIsSeven, UInt128 maxK, ref bool isPrime)
{
var gpuLease = GpuKernelPool.GetKernel(_useGpuOrder);
var execution = gpuLease.EnterExecutionScope();
var accelerator = gpuLease.Accelerator;
var stream = gpuLease.Stream;
int batchSize = GpuConstants.ScanBatchSize; // large batch improves GPU occupancy and avoids TDR
UInt128 kStart = UInt128.One;
ulong divMul = (ulong)((((UInt128)1 << 64) - UInt128.One) / exponent) + 1UL;
@@ -23,45 +25,51 @@ public class MersenneNumberOrderGpuTester(GpuKernelType kernelType, bool useGpuO
};
var foundBuffer = accelerator.Allocate1D<int>(1);
UInt128 remaining;
int currentSize;
int found = 0;
while (kStart <= maxK && Volatile.Read(ref isPrime))
try
{
remaining = maxK - kStart + 1UL;
currentSize = remaining > (UInt128)batchSize ? batchSize : (int)remaining;
foundBuffer.MemSetToZero();
// Precompute residue automaton bases for this batch
UInt128 q0 = twoP * kStart + 1UL;
ulong q0m10 = q0.Mod10();
ulong q0m8 = q0.Mod8();
ulong q0m3 = q0.Mod3();
ulong q0m5 = q0.Mod5();
ulong step10 = ((exponent % 10UL) << 1) % 10UL;
ulong step8 = ((exponent & 7UL) << 1) & 7UL;
ulong step3 = ((exponent % 3UL) << 1) % 3UL;
ulong step5 = ((exponent % 5UL) << 1) % 5UL;
var ra = new ResidueAutomatonArgs(q0m10, step10, q0m8, step8, q0m3, step3, q0m5, step5);
// Ensure device has small cycles table for early rejections in order kernels
var smallCyclesView = GpuKernelPool.EnsureSmallCyclesOnDevice(accelerator);
kernel(currentSize, exponent, (GpuUInt128)twoP, (GpuUInt128)kStart, last, divMul,
ra, foundBuffer.View, smallCyclesView);
accelerator.Synchronize();
foundBuffer.View.CopyToCPU(ref found, 1);
if (found != 0)
UInt128 remaining;
int currentSize;
int found = 0;
while (kStart <= maxK && Volatile.Read(ref isPrime))
{
Volatile.Write(ref isPrime, false);
break;
remaining = maxK - kStart + 1UL;
currentSize = remaining > (UInt128)batchSize ? batchSize : (int)remaining;
foundBuffer.MemSetToZero();
// Precompute residue automaton bases for this batch
UInt128 q0 = twoP * kStart + 1UL;
ulong q0m10 = q0.Mod10();
ulong q0m8 = q0.Mod8();
ulong q0m3 = q0.Mod3();
ulong q0m5 = q0.Mod5();
ulong step10 = ((exponent % 10UL) << 1) % 10UL;
ulong step8 = ((exponent & 7UL) << 1) & 7UL;
ulong step3 = ((exponent % 3UL) << 1) % 3UL;
ulong step5 = ((exponent % 5UL) << 1) % 5UL;
var ra = new ResidueAutomatonArgs(q0m10, step10, q0m8, step8, q0m3, step3, q0m5, step5);
// Ensure device has small cycles table for early rejections in order kernels
var smallCyclesView = GpuKernelPool.EnsureSmallCyclesOnDevice(accelerator);
kernel(stream, currentSize, exponent, (GpuUInt128)twoP, (GpuUInt128)kStart, last, divMul,
ra, foundBuffer.View, smallCyclesView);
stream.Synchronize();
foundBuffer.View.CopyToCPU(ref found, 1);
if (found != 0)
{
Volatile.Write(ref isPrime, false);
break;
}
kStart += (UInt128)currentSize;
}
kStart += (UInt128)currentSize;
}
foundBuffer.Dispose();
gpuLease.Dispose();
finally
{
foundBuffer.Dispose();
execution.Dispose();
gpuLease.Dispose();
}
}
}