diff options
| author | wollman <wollman@FreeBSD.org> | 1996-03-29 17:48:21 +0000 |
|---|---|---|
| committer | wollman <wollman@FreeBSD.org> | 1996-03-29 17:48:21 +0000 |
| commit | b8629671223d1be1afab479da0d0326bb91b90da (patch) | |
| tree | 33e2ea5793fa935cf236a739e3a52b2cd2afad1a /sys | |
| parent | 92cff4dcbb07770905a96ab952815ab50e1b9675 (diff) | |
| download | FreeBSD-src-b8629671223d1be1afab479da0d0326bb91b90da.zip FreeBSD-src-b8629671223d1be1afab479da0d0326bb91b90da.tar.gz | |
There is no need to zero out the TSC when configuring a counter,
says Mike Haertel.
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/i386/i386/perfmon.c | 17 |
1 files changed, 3 insertions, 14 deletions
diff --git a/sys/i386/i386/perfmon.c b/sys/i386/i386/perfmon.c index 138d5d7..cde2455 100644 --- a/sys/i386/i386/perfmon.c +++ b/sys/i386/i386/perfmon.c @@ -26,7 +26,7 @@ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: perfmon.c,v 1.2 1996/03/27 22:02:18 wollman Exp $ + * $Id: perfmon.c,v 1.4 1996/03/28 21:00:29 wollman Exp $ */ #include <sys/param.h> @@ -240,20 +240,9 @@ writectl5(int pmc) newval |= P5FLAG_E; newval |= ctl_shadow[0] & 0x3f; } - /* - * ``...But this is the blackest of sins!'' - * - * According to the Harvard code, it is necessary to zero the - * cycle counter before writing to the control MSR. This must - * be an Intel processor... Hope we don't lose too many ticks. - */ - disable_intr(); - oldtsc = rdtsc(); - wrmsr(0x10 /* TSC */, 0); + wrmsr(msr_ctl[0], newval); - wrmsr(0x10, oldtsc); - enable_intr(); - return 0; /* XXX should check for errors */ + return 0; /* XXX should check for unimplemented bits */ } /* |
