NAME
pmc.tsc —
measurements using the i386 timestamp
counter
LIBRARY
Performance Counters Library (libpmc, -lpmc)
SYNOPSIS
#include
<pmc.h>
DESCRIPTION
In the i386 architecture, the timestamp counter is a monotonically non-decreasing counter that counts processor cycles.
This counter may be selected specifying an event specifier
“tsc” to
pmc_allocate(3). The TSC is a read-only counter that may only
be allocated in system-wide counting mode. The
“tsc” event does not support further
event qualifiers.
Multiple processes are allowed to allocate the TSC.
Once allocated, the TSC may be read using the
pmc_read()
function, or by using the RDTSC instruction.
Event Name Aliases
The alias “cycles” maps to
the TSC.
SEE ALSO
pmc(3), pmc.amd(3), pmc.atom(3), pmc.core(3), pmc.core2(3), pmc.iaf(3), pmc.soft(3), pmclog(3), hwpmc(4)
HISTORY
The pmc library first appeared in
FreeBSD 6.0.
AUTHORS
The Performance Counters Library (libpmc, -lpmc) library was written by Joseph Koshy <jkoshy@FreeBSD.org>.