pmc_control man page on NetBSD

Man page or keyword search:  
man Server   9087 pages
apropos Keyword Search (all sections)
Output format
NetBSD logo
[printable version]

PMC_CONTROL(2)		    BSD System Calls Manual		PMC_CONTROL(2)

NAME
     pmc_control, pmc_get_info — Hardware Performance Monitoring Interface

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/pmc.h>

     int
     pmc_control(int ctr, int op, void *argp);

     int
     pmc_get_info(int ctr, int op, void *argp);

DESCRIPTION
     pmc_get_info() returns the number of counters in the system or informa‐
     tion on a specified counter ctr.  The possible values for op are:

     PMC_INFO_NCOUNTERS
	    When querying the number of counters in the system, ctr is ignored
	    and argp is of type int *.	Upon return, the integer pointed to by
	    argp will contain the number of counters that are available in the
	    system.

     PMC_INFO_CPUCTR_TYPE
	    When querying the type of a counter in the system, ctr refers to
	    the counter being queried, and argp is of type int *.  Upon
	    return, the integer pointed to by argp will contain the implemen‐
	    tation-dependent type of the specified counter.

	    If ctr is -1, the integer pointed to by argp will contain the
	    machine-dependent type describing the CPU or counter configura‐
	    tion.

     PMC_INFO_COUNTER_VALUE
	    When querying the value of a counter in the system, ctr refers to
	    the counter being queried, and argp is of type uint64_t *.	Upon
	    return, the 64-bit integer pointed to by argp will contain the
	    value of the specified counter.

     PMC_INFO_ACCUMULATED_COUNTER_VALUE
	    When querying the value of a counter in the system, ctr refers to
	    the counter being queried, and argp is of type uint64_t *.	Upon
	    return, the 64-bit integer pointed to by argp will contain the sum
	    of the accumulated values of specified counter in all exited sub‐
	    processes of the current process.

     pmc_control() manipulates the specified counter ctr in one of several
     fashions.	The op parameter determines the action taken by the kernel and
     also the interpretation of the argp parameter.  The possible values for
     op are:

     PMC_OP_START
	    Starts the specified ctr running.  It must be preceded by a call
	    with PMC_OP_CONFIGURE.  argp is ignored in this case and may be
	    NULL.

     PMC_OP_STOP
	    Stops the specified ctr from running.  argp is ignored in this
	    case and may be NULL.

     PMC_OP_CONFIGURE
	    Configures the specified ctr prior to running.  argp is a pointer
	    to a struct pmc_counter_cfg.

		    struct pmc_counter_cfg {
			    pmc_evid_t	    event_id;
			    pmc_ctr_t	    reset_value;
			    uint32_t	    flags;
		    };

	    event_id
		   is the event ID to be counted.

	    reset_value
		   is a value to which the counter should be reset on overflow
		   (if supported by the implementation).  This is most useful
		   when profiling (see PMC_OP_PROFSTART, below).  This value
		   is defined to be the number of counter ticks before the
		   next overflow.  So, to get a profiling tick on every hun‐
		   dredth data cache miss, set the event_id to the proper
		   value for “dcache-miss” and set reset_value to 100.

	    flags  Currently unused.

     PMC_OP_PROFSTART
	    Configures the specified ctr for use in profiling.	argp is a
	    pointer to a struct pmc_counter_cfg as in PMC_OP_CONFIGURE, above.
	    This request allocates a kernel counter, which will fail if any
	    process is using the requested counter.  Not all implementations
	    or counters may support this option.

     PMC_OP_PROFSTOP
	    Stops the specified ctr from being used for profiling.  argp is
	    ignored in this case and may be NULL.

RETURN VALUES
     A return value of 0 indicates that the call succeeded.  Otherwise, -1 is
     returned and the global variable errno is set to indicate the error.

ERRORS
     Among the possible error codes from pmc_control() and pmc_get_info() are

     [EFAULT]		The address specified for the argp is invalid.

     [ENXIO]		Specified counter is not yet configured.

     [EINPROGRESS]	PMC_OP_START was passed for a counter that is already
			running.

     [EINVAL]		Specified counter was invalid.

     [EBUSY]		If the requested counter is already in use--either by
			the current process or by the kernel.

     [ENODEV]		If and only if the specified counter event is not
			valid for the specified counter when configuring a
			counter or starting profiling.

     [ENOMEM]		If the kernel is unable to allocate memory.

SEE ALSO
     pmc(1), pmc(9)

HISTORY
     The pmc_control() and pmc_get_info() system calls appeared in NetBSD 2.0.

BSD			       October 27, 2005				   BSD
[top]
                             _         _         _ 
                            | |       | |       | |     
                            | |       | |       | |     
                         __ | | __ __ | | __ __ | | __  
                         \ \| |/ / \ \| |/ / \ \| |/ /  
                          \ \ / /   \ \ / /   \ \ / /   
                           \   /     \   /     \   /    
                            \_/       \_/       \_/ 
More information is available in HTML format for server NetBSD

List of man pages available for NetBSD

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net