- Remove 'struct vmmeter' from 'struct pcpu', leaving only global vmmeter

  in place.  To do per-cpu stats, convert all fields that previously were
  maintained in the vmmeters that sit in pcpus to counter(9).
- Since some vmmeter stats may be touched at very early stages of boot,
  before we have set up UMA and we can do counter_u64_alloc(), provide an
  early counter mechanism:
  o Leave one spare uint64_t in struct pcpu, named pc_early_dummy_counter.
  o Point counter(9) fields of vmmeter to pcpu[0].pc_early_dummy_counter,
    so that at early stages of boot, before counters are allocated we already
    point to a counter that can be safely written to.
  o For sparc64 that required a whole dummy pcpu[MAXCPU] array.

Further related changes:
- Don't include vmmeter.h into pcpu.h.
- vm.stats.vm.v_swappgsout and vm.stats.vm.v_swappgsin changed to 64-bit,
  to match kernel representation.
- struct vmmeter hidden under _KERNEL, and only vmstat(1) is an exclusion.

This is based on benno@'s 4-year old patch:
https://lists.freebsd.org/pipermail/freebsd-arch/2013-July/014471.html

Reviewed by:	kib, gallatin, marius, lidl
Differential Revision:	https://reviews.freebsd.org/D10156

1 files changed, 5 insertions, 3 deletions

diff --git a/libexec/rpc.rstatd/rstat_proc.c b/libexec/rpc.rstatd/rstat_proc.c
index 18fe27e2064f..f0f2ffd65b57 100644
--- a/libexec/rpc.rstatd/rstat_proc.c
+++ b/libexec/rpc.rstatd/rstat_proc.c
@@ -170,6 +170,7 @@ updatestat(void)
 	struct timeval tm, btm;
 	int mib[6];
 	size_t len;
+	uint64_t val;
 	int ifcount;
 
 #ifdef DEBUG
@@ -229,11 +230,12 @@ updatestat(void)
 #endif
 
 #define	FETCH_CNT(stat, cnt) do {					\
-	len = sizeof((stat));						\
-	if (sysctlbyname("vm.stats." #cnt , &(stat), &len, 0, 0) < 0) { \
-		syslog(LOG_ERR, "sysctl(vm.stats." #cnt "): %m"); \
+	len = sizeof(uint64_t);						\
+	if (sysctlbyname("vm.stats." #cnt , &val, &len, NULL, 0) < 0) {	\
+		syslog(LOG_ERR, "sysctl(vm.stats." #cnt "): %m");	\
 		exit(1);						\
 	}								\
+	stat = val;							\
 } while (0)
 
 	FETCH_CNT(stats_all.s1.v_pgpgin, vm.v_vnodepgsin);