Jocl和Device Fission

Question

编辑：问题解决了！ rzymek的回答很有帮助。

问题：对于JOCL，如何从设备分裂的opencl计算中排除某些CPU内核？（对于0.1.9版本，cl_device_partition_property的Java端口似乎已损坏）

编辑：我发现了这个：

clCreateSubDevices(devices[0][1],core , 1, cpuCores, coreIDs);

但是java / jocl不接受这个：

cl_device_partition_property core=CL.CL_DEVICE_PARTITION_BY_COUNTS;

错误是：

Type mismatch: cannot convert from int to cl_device_partition_property

尝试null初始化然后使用变量自己的方法来设置属性：

    cl_device_partition_property core = null;
    core.addProperty(CL_DEVICE_PARTITION_BY_COUNTS, platforms[0]);

编辑：现在它给出了

    java.lang.NullPointerException,

错误。

IT需要是unsigned int（不是cl_device_partition_property），但java没有它。

使用构造函数进行新尝试：

cl_device_partition_property core = new cl_device_partition_property();

错误：

 A fatal error has been detected by the Java Runtime Environment:
#
#  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000007fedb6500bf, pid=4952, tid=4852
#
# JRE version: 7.0_21-b11
# Java VM: Java HotSpot(TM) 64-Bit Server VM (23.21-b01 mixed mode windows-amd64 compressed oops)
# Problematic frame:
# C  [amdocl64.dll+0x1800bf]  clGetSamplerInfo+0x1972f
#
# Failed to write core dump. Minidumps are not enabled by default on client versions of     Windows
#
# An error report file with more information is saved as:
# C:\javalar\buraya\paralelProje\hs_err_pid4952.log
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.sun.com/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
#

[error occurred during error reporting , id 0xc0000005]

另一次尝试：

    cl_device_partition_property core =  (CL_UNSIGNED_INT32)CL_DEVICE_PARTITION_BY_COUNTS;

错误：

CL_UNSIGNED_INT32 cannot be resolved to a type

这也不起作用：

   Pointer xyz=Pointer.to(core); // jocl's pointer type.
   clCreateSubDevices(device,xyz, 1, cpuCores, coreIDs);

编辑：问题解决了！谢谢。现在可以对我的cpu进行分区：

Answer 1

我认为这是JOCL缺少的功能。 我想你可以尝试这两种解决方法。

假设您要设置此属性列表：

{ CL_DEVICE_PARTITION_BY_COUNTS, 3, 1, CL_DEVICE_PARTITION_BY_COUNTS_LIST_END, 0 }

（摘自http://software.intel.com/en-us/articles/opencl-device-fission-for-cpu-performance的财产清单示例。）

解决方法1 ：

cl_device_partition_property properties = new cl_device_partition_property();
properties.addProperty(CL.CL_DEVICE_PARTITION_BY_COUNTS, 3);
properties.addProperty(1, CL.CL_DEVICE_PARTITION_BY_COUNTS_LIST_END);

说明：addProperty方法只将id和值附加到long []数组的末尾，并将其转换为Buffer：

public void addProperty(long id, long value)
{
    LongBuffer oldBuffer = (LongBuffer)getBuffer();
    long newArray[] = new long[oldBuffer.capacity()+2];
    oldBuffer.get(newArray, 0, oldBuffer.capacity());
    newArray[oldBuffer.capacity()-1] = id;
    newArray[oldBuffer.capacity()+0] = value;
    newArray[oldBuffer.capacity()+1] = 0;
    setBuffer(LongBuffer.wrap(newArray));
}

因此可以创建任何列表，如：

addProperty(item[0], item[1]);
addProperty(item[2], item[3]);
addProperty(item[4], item[5]);
addProperty(item[6], 0);

解决方法2：

在org.jcol包中创建一个类，以访问受限制的方法setBuffer：

package org.jocl;

import java.nio.LongBuffer;

public class cl_device_partition_property_gateway {
    public static void set(cl_device_partition_property properties, long[] newArray) {
        properties.setBuffer(LongBuffer.wrap(newArray));
    }
}

然后你可以直接设置long []数组：

cl_device_partition_property properties = new cl_device_partition_property();
long[] values = { CL.CL_DEVICE_PARTITION_BY_COUNTS, 3, 1, 
    CL.CL_DEVICE_PARTITION_BY_COUNTS_LIST_END, 0 };
cl_device_partition_property_gateway.set(properties, values);