| PMC.TSC(3) | MidnightBSD Library Functions Manual | PMC.TSC(3) |
pmc.tsc —
measurements using the i386 timestamp counter
Performance Counters Library (libpmc, -lpmc)
#include
<pmc.h>
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.
The alias “cycles” maps to
the TSC.
pmc(3), pmc.atom(3), pmc.core(3), pmc.core2(3), pmc.iaf(3), pmc.k7(3), pmc.k8(3), pmc.p4(3), pmc.p5(3), pmc.p6(3), pmc.soft(3), pmclog(3), hwpmc(4)
The pmc library first appeared in
FreeBSD 6.0.
The Performance Counters Library (libpmc, -lpmc) library was written by Joseph Koshy <jkoshy@FreeBSD.org>.
| October 4, 2008 | midnightbsd-3.1 |