On Tue, May 02, 2017 at 11:31:21PM +1000, Bruce Evans wrote: > On Tue, 2 May 2017, Konstantin Belousov wrote: > > ENOMEM is, of course, the situation which I want to avoid. > > Then you have to return no error, but truncate the value instead of > clamping. Anything else is incompatible. I do not quite agree with the truncation part, bit I do not think that it is too important. As I noted before, IMO the absolute numbers for the counters have more values than per-interval diffs displayed by e.g. systat. But if truncating causes less disagreement than clamping, lets do truncation.
diff --git a/sys/vm/vm_meter.c b/sys/vm/vm_meter.c index 5f4cd46ab1e..6266ef670a6 100644 --- a/sys/vm/vm_meter.c +++ b/sys/vm/vm_meter.c @@ -266,8 +266,27 @@ static SYSCTL_NODE(_vm_stats, OID_AUTO, vm, CTLFLAG_RW, 0, "VM meter vm stats"); SYSCTL_NODE(_vm_stats, OID_AUTO, misc, CTLFLAG_RW, 0, "VM meter misc stats"); +static int +sysctl_handle_vmstat(SYSCTL_HANDLER_ARGS) +{ + uint64_t out; +#ifdef COMPAT_FREEBSD11 + uint32_t out32; +#endif + + out = counter_u64_fetch(*(counter_u64_t *)arg1); +#ifdef COMPAT_FREEBSD11 + if (req->oldlen == sizeof(out32)) { + out32 = (uint32_t)out; /* truncate */ + return (SYSCTL_OUT(req, &out32, sizeof(out32))); + } +#endif + return (SYSCTL_OUT(req, &out, sizeof(out))); +} + #define VM_STATS(parent, var, descr) \ - SYSCTL_COUNTER_U64(parent, OID_AUTO, var, CTLFLAG_RD, &vm_cnt.var, descr) + SYSCTL_OID(parent, OID_AUTO, var, CTLTYPE_U64 | CTLFLAG_MPSAFE | \ + CTLFLAG_RD, &vm_cnt.var, 0, sysctl_handle_vmstat, "QU", descr); #define VM_STATS_VM(var, descr) VM_STATS(_vm_stats_vm, var, descr) #define VM_STATS_SYS(var, descr) VM_STATS(_vm_stats_sys, var, descr) _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"