symbols

Enables and configures symbol decoding support.

-symbols [cacheonly] [verbose] [dbghelplog]

Parameters

cacheonly

Use the symcache, but not DbgHelp. This option is used to speed up symbol decoding for traces with many binary images missing symbol files once all interesting symbol files have been transcoded.

verbose

Verbose mode. Print configuration.

dbghelplog

Enable DbgHelp debug log on stderr.

If action symbols is not specified on the command line, symbol decoding is disabled.

The symbol decoding support uses the following environment variables for further configuration of DbgHelp and SymCache:

_NT_SYMBOL_PATH	Specifies the path DbgHelp should search to locate symbols files (.PDB) corresponding to binary images files used in the trace. See Note below regarding this variable.
_NT_SYMCACHE_PATH	Specifies the path to the local symcache directory. By default, \SymCache will be used.

Comments

For symbol decoding, the trace must be a kernel trace (or a user trace processed in conjunction with a kernel trace) that has the PROC_THREAD+LOADER kernel flags enabled and has been stopped and merged with -d or merged with -merge on the same machine it was taken on. [xperf performs a special image identification process during its custom trace merge.]

Microsoft Symbol Server-based configuration set _NT_SYMBOL_PATH=srv*%SystemDrive%\symbols*http://msdl.microsoft.com/download/symbols

Configure SymCache to always use the System drive: set _NT_SYMCACHE_PATH=%SystemDrive%\SymCache

If you have any non-Microsoft applications installed, add the path to their symbols to the path for OS symbols: set _NT_SYMBOL_PATH=srv*%SystemDrive%\symbols*http://msdl.microsoft.com/download/symbols;C:\\MyPrivates.