Intel IXP400 manual C0112788 No lower symbol found. Module kernel

Intel® IXP400 Software

Access-Layer Components: Performance Profiling (IxPerfProfAcc) API

As this file system is temporary, the user is required to copy the output file into a permanent location or else the results will be lost when a new round of sampling is done or when the system is stopped or rebooted.

Sample file output for Linux is as follows:

Total Number of Samples for Event1 = 0
Hits	PC Address Symbol Address Offset Routine
------- ---------- -------------- ------ -------------------
Total Number of Samples for Event2 = 0
Hits	PC Address Symbol Address Offset Routine
------- ---------- -------------- ------ -------------------
Total Number of Samples for Event3 = 65535
Hits	PC Address	Symbol Address	Offset	Routine
-------	------------	------------	------	-------------------------------------------
21814	c004dd38	c004dac4	274	schedule [Module - kernel]
21381	c0058cac	c0058c7c	30	add_timer [Module - kernel]
21329	c00594a4	c005949c	8	schedule_timeout [Module - kernel]
189	c0058c84	c0058c7c	8	add_timer [Module - kernel]
124	c0059520	c005949c	84	schedule_timeout [Module - kernel]
95	c00594a8	c005949c	c	schedule_timeout [Module - kernel]

Total	Number of Samples for Event4 = 6
Hits	PC Address	Symbol	Address Offset	Routine
-----	-----------	-------	---------------	-------------------
5	c004dd38	c004dac4	274	schedule [Module - kernel]
1	c0112788	0 c0112788	No lower symbol found. [Module - kernel]

VxWorks output is identical, but also includes a Percent column. In Linux, the user is also able to change the accuracy of matching the PC Address to the Symbol Address. The greater the accuracy required, the longer it takes to find a match. The recommended accuracy is 0xffff which means the module will reduce the PC Address by up to 0xffff until it can find a match. Else, a message is logged and “No symbol found” is written to the file. The accuracy can be changed by modifying the #define IX_PERFPROF_ACC_XSCALE_PMU_SYMBOL_ACCURACY.

The output filename is defined in IxPerfProfAcc. To use a different filename, the user is required to change the filename in the stop function for vxWorks or the ixPerfProfAccXscalePmuTimeSampCreateProcFile() function in Linux.

Note: The Linux proc file create API is declared public so that it can be called by the /proc file system. It should never be called directly by the user.

Programmer’s Guide	IXP400 Software Version 2.0	April 2005
	Document Number: 252539, Revision: 007	259