| Debugging Tools for Windows |
Beginning in Windows Vista, you can configure the Special Pool feature as a kernel flag setting or as a registry setting. If you configure it as a kernel flag (run time) setting, you do not need to restart the computer to make the change effective. In earlier versions of Windows, Special Pool is available only as a registry setting.
Also, beginning in Windows Vista, you can set and configure the Special Pool feature from the command line. In earlier versions of Windows, you can set and configure the Special Pool feature only in the Global Flags dialog box.
The following command requests special pool for all allocations with the Tag1 pool tag. This setting becomes effective immediately, but it is lost if you shut down or restart Windows.
This command uses the /k parameter to specify a kernel flag (run time) setting and the
Gflags responds by printing:
PoolTagOverruns set to 0x1
Current Running Kernel Settings are: 00000000
Notice that the special pool allocation request is not a kernel flag setting and is not reflected in the kernel settings value.
Also, a special pool allocation request does not change the value of the overrun (0x1) or underrun (0x0) setting for special pool. To change from overruns, the default, to underruns, use the Gflags Dialog Box. For information, see Detecting Overruns and Underruns.
You cannot display the pool tag at the command line. To verify that the pool tag is a kernel setting, use the Gflags Dialog Box.
The following command requests special pool for all allocations with the Tag1 pool tag. Because this setting is stored in the registry, you must restart the computer to make it effective, but it remains effective until you change it.
This command uses the /r parameter to specify a registry setting and the
Gflags responds by printing:
PoolTagOverruns set to 0x1
Current Boot Registry Settings are: 00000000
Notice that the special pool allocation request is not a registry flag setting and is not reflected in the registry settings value.
Also, a special pool allocation request does not change the value of the overrun (0x1) or underrun (0x0) setting for special pool. To change from overruns, the default, to underruns, use the Gflags Dialog Box. For information, see Detecting Overruns and Underruns.
To verify that the value has been added to the registry, use Reg or Regedit to display the value of the PoolTag entry in the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management key.
For example:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
PoolTag REG_DWORD 0x31676154
The following command requests special pool for allocations of 1 to 8 bytes on an x86 computer with a PAGE_SIZE of 0x1000 and allocation granularity of 8 bytes.
This command uses the /k parameter to specify a kernel flag (run time) setting and the
The value, 0x10, is calculated by adding the allocation granularity (8 bytes) to the largest size in the range (8 bytes) for a total of 16 bytes (0x10). For help in determining the correct value to enter, see "Selecting an Allocation Size" in Special Pool.
Gflags responds by printing:
PoolTagOverruns set to 0x1
Current Running Kernel Settings are: 00000000
Again, the special pool allocation request is not a kernel flag setting and is not reflected in the kernel settings value.
Also, a special pool allocation request does not change the value of the overrun (0x1) or underrun (0x0) setting for special pool. To change from overruns, the default, to underruns, use the Gflags Dialog Box. For information, see Detecting Overruns and Underruns.
The following command requests special pool for allocations of
This command uses the /r parameter to specify a system-wide registry setting and the
The value, 0x420, is calculated by adding the allocation granularity (16 bytes) to the largest size in the range (1040 bytes) for a total of 1056 bytes (0x420). For help in determining the correct value to enter, see "Selecting an Allocation Size" in Special Pool.
Gflags responds by printing:
PoolTagOverruns set to 0x1
Current Boot Registry Settings are: 00000000
Again, the special pool allocation request is not a registry flag setting and is not reflected in the registry settings value.
Also, a special pool allocation request does not change the value of the overrun (0x1) or underrun (0x0) setting for special pool. To change from overruns, the default, to underruns, use the Gflags Dialog Box. For information, see Detecting Overruns and Underruns.
To verify that the value has been added to the registry, use Reg or Regedit to display the value of the PoolTag entry in the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management key.
For example:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
PoolTag REG_DWORD 0x420
The following command cancels a request for Special Pool as a kernel flag (run time) setting. The command is the same for a request by pool tag or by size.
The following command cancels a request for Special Pool as a registry setting. The command is the same for a request by pool tag or by size.
When the command is successful, Gflags responds by printing: