Author: jkim
Date: Tue Apr 12 23:49:07 2011
New Revision: 220584
URL: http://svn.freebsd.org/changeset/base/220584
Log:
Reduce errors in effective frequency calculation.
Modified:
head/sys/amd64/amd64/machdep.c
head/sys/i386/i386/machdep.c
Modified: head/sys/amd64/amd64/machdep.c
==============================================================================
--- head/sys/amd64/amd64/machdep.c Tue Apr 12 23:04:01 2011
(r220583)
+++ head/sys/amd64/amd64/machdep.c Tue Apr 12 23:49:07 2011
(r220584)
@@ -546,7 +546,7 @@ int
cpu_est_clockrate(int cpu_id, uint64_t *rate)
{
uint64_t tsc1, tsc2;
- uint64_t acnt, mcnt;
+ uint64_t acnt, mcnt, perf;
register_t reg;
if (pcpu_find(cpu_id) == NULL || rate == NULL)
@@ -579,7 +579,8 @@ cpu_est_clockrate(int cpu_id, uint64_t *
acnt = rdmsr(MSR_APERF);
tsc2 = rdtsc();
intr_restore(reg);
- *rate = (tsc2 - tsc1) / 1000 * acnt / mcnt * 1000000;
+ perf = 1000 * acnt / mcnt;
+ *rate = (tsc2 - tsc1) * perf;
} else {
tsc1 = rdtsc();
DELAY(1000);
Modified: head/sys/i386/i386/machdep.c
==============================================================================
--- head/sys/i386/i386/machdep.c Tue Apr 12 23:04:01 2011
(r220583)
+++ head/sys/i386/i386/machdep.c Tue Apr 12 23:49:07 2011
(r220584)
@@ -1137,7 +1137,7 @@ int
cpu_est_clockrate(int cpu_id, uint64_t *rate)
{
uint64_t tsc1, tsc2;
- uint64_t acnt, mcnt;
+ uint64_t acnt, mcnt, perf;
register_t reg;
if (pcpu_find(cpu_id) == NULL || rate == NULL)
@@ -1172,7 +1172,8 @@ cpu_est_clockrate(int cpu_id, uint64_t *
acnt = rdmsr(MSR_APERF);
tsc2 = rdtsc();
intr_restore(reg);
- *rate = (tsc2 - tsc1) / 1000 * acnt / mcnt * 1000000;
+ perf = 1000 * acnt / mcnt;
+ *rate = (tsc2 - tsc1) * perf;
} else {
tsc1 = rdtsc();
DELAY(1000);
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