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If possible, try to obtain max_mhz on cpufreq attach instead of first request.

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On HyperThreading CPUs logical cores have same frequency, so setting it
on any core will change the other's one. In most cases first request
to the second core will be the "set" request, done after setting frequency
of the first core. In such case second CPU will obtain throttled frequency
of the first core as it's max_mhz making cpufreq broken due to different
frequency sets.
This commit is contained in:
mav 2008-12-16 01:24:05 +00:00
parent e1f9a89b0d
commit 325d9e1d23
1 changed files with 8 additions and 1 deletions
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9
sys/kern/kern_cpu.c
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@ -144,7 +144,9 @@ static int
cpufreq_attach(device_t dev)
{
struct cpufreq_softc *sc;
struct pcpu *pc;
device_t parent;
uint64_t rate;
int numdevs;
CF_DEBUG("initializing %s\n", device_get_nameunit(dev));
@ -156,7 +158,12 @@ cpufreq_attach(device_t dev)
CF_MTX_INIT(&sc->lock);
sc->curr_level.total_set.freq = CPUFREQ_VAL_UNKNOWN;
SLIST_INIT(&sc->saved_freq);
sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
/* Try to get current CPU freq to use it as maximum later if needed */
pc = cpu_get_pcpu(dev);
if (cpu_est_clockrate(pc->pc_cpuid, &rate) == 0)
sc->max_mhz = rate / 1000000;
else
sc->max_mhz = CPUFREQ_VAL_UNKNOWN;
/*
* Only initialize one set of sysctls for all CPUs. In the future,