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Use 64-bit arithmetic throughout, and lock accesses to globals.

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With this change, dbench with >= 4 processes runs without getting
weird jumps forward in time when the APCI pmtimer is the default
timecounter.

Obtained from:	NetApp
This commit is contained in:
Peter Grehan 2013-01-07 04:51:43 +00:00
parent 03429e45a7
commit 5fdfc2b893
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/projects/bhyve/; revision=245123
1 changed files with 13 additions and 6 deletions
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19
usr.sbin/bhyve/pmtmr.c
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@ -37,6 +37,7 @@ __FBSDID("$FreeBSD$");
#include <stdio.h>
#include <time.h>
#include <assert.h>
#include <pthread.h>
#include "inout.h"
@ -51,36 +52,42 @@ __FBSDID("$FreeBSD$");
#define PMTMR_FREQ 3579545 /* 3.579545MHz */
static uint32_t pmtmr_tscf;
static uint32_t pmtmr_old;
static pthread_mutex_t pmtmr_mtx;
static uint64_t pmtmr_tscf;
static uint64_t pmtmr_old;
static uint64_t pmtmr_tsc_old;
static uint32_t
pmtmr_val(void)
{
uint64_t pmtmr_tsc_new;
uint32_t pmtmr_new;
uint64_t pmtmr_new;
static int inited = 0;
if (!inited) {
size_t len;
uint32_t tmpf;
inited = 1;
len = sizeof(pmtmr_tscf);
sysctlbyname("machdep.tsc_freq", &pmtmr_tscf, &len,
pthread_mutex_init(&pmtmr_mtx, NULL);
len = sizeof(tmpf);
sysctlbyname("machdep.tsc_freq", &tmpf, &len,
NULL, 0);
pmtmr_tscf = tmpf;
pmtmr_tsc_old = rdtsc();
pmtmr_old = pmtmr_tsc_old / pmtmr_tscf * PMTMR_FREQ;
return (pmtmr_old);
}
pthread_mutex_lock(&pmtmr_mtx);
pmtmr_tsc_new = rdtsc();
pmtmr_new = (pmtmr_tsc_new - pmtmr_tsc_old) * PMTMR_FREQ / pmtmr_tscf +
pmtmr_old;
pmtmr_old = pmtmr_new;
pmtmr_tsc_old = pmtmr_tsc_new;
pthread_mutex_unlock(&pmtmr_mtx);
return (pmtmr_old);
return (pmtmr_new);
}
static int