Author: uqs
Date: Tue Nov 23 21:36:53 2010
New Revision: 215774
URL: http://svn.freebsd.org/changeset/base/215774
Log:
MFC r214237,214489:
Remove mention of non-existant -o flag for debugging options.
Fix CPU load reporting independent of scheduler used.
- Sample CPU usage data from kern.cp_times, this makes for a far more
accurate and scheduler independent algorithm.
- Rip out the process list scraping that is no longer required.
- Don't update CPU usage sampling on every request, but every 15s
instead. This makes it impossible for an attacker to hide the CPU load
by triggering 4 samplings in short succession when the system is idle.
- After reaching the steady-state, the system will always report the
average CPU load of the last 60 sampled seconds.
- Untangling of call graph.
Modified:
stable/7/contrib/bsnmp/snmpd/bsnmpd.1 (contents, props changed)
stable/7/usr.sbin/bsnmpd/modules/snmp_hostres/hostres_processor_tbl.c
(contents, props changed)
Changes in other areas also in this revision:
Modified:
stable/8/contrib/bsnmp/snmpd/bsnmpd.1 (contents, props changed)
stable/8/usr.sbin/bsnmpd/modules/snmp_hostres/hostres_processor_tbl.c
(contents, props changed)
Modified: stable/7/contrib/bsnmp/snmpd/bsnmpd.1
==============================================================================
--- stable/7/contrib/bsnmp/snmpd/bsnmpd.1 Tue Nov 23 21:35:13 2010
(r215773)
+++ stable/7/contrib/bsnmp/snmpd/bsnmpd.1 Tue Nov 23 21:36:53 2010
(r215774)
@@ -31,7 +31,7 @@
.\"
.\" $Begemot: bsnmp/snmpd/bsnmpd.1,v 1.12 2006/02/27 09:50:03 brandt_h Exp $
.\"
-.Dd August 16, 2010
+.Dd October 23, 2010
.Dt BSNMPD 1
.Os
.Sh NAME
@@ -68,11 +68,9 @@ Use
.Ar file
as configuration file instead of the standard one.
.It Fl D Ar options
-Debugging options are specified with a
-.Fl o
-flag followed by a comma separated string of options.
+Debugging options are specified as a comma separated string.
The following options are available.
-.Bl -tag -width ".It Cm trace Ns Cm = Ns Cm level"
+.Bl -tag -width "trace=level"
.It Cm dump
Dump all sent and received PDUs to the terminal.
.It Cm events
Modified: stable/7/usr.sbin/bsnmpd/modules/snmp_hostres/hostres_processor_tbl.c
==============================================================================
--- stable/7/usr.sbin/bsnmpd/modules/snmp_hostres/hostres_processor_tbl.c
Tue Nov 23 21:35:13 2010 (r215773)
+++ stable/7/usr.sbin/bsnmpd/modules/snmp_hostres/hostres_processor_tbl.c
Tue Nov 23 21:36:53 2010 (r215774)
@@ -56,19 +56,15 @@
struct processor_entry {
int32_t index;
const struct asn_oid *frwId;
- int32_t load;
+ int32_t load; /* average cpu usage */
+ int32_t sample_cnt; /* number of usage samples */
+ int32_t cur_sample_idx; /* current valid sample */
TAILQ_ENTRY(processor_entry) link;
u_char cpu_no; /* which cpu, counted from 0 */
- pid_t idle_pid; /* PID of idle process for this CPU */
/* the samples from the last minute, as required by MIB */
double samples[MAX_CPU_SAMPLES];
-
- /* current sample to fill in next time, must be < MAX_CPU_SAMPLES */
- uint32_t cur_sample_idx;
-
- /* number of useful samples */
- uint32_t sample_cnt;
+ long states[MAX_CPU_SAMPLES][CPUSTATES];
};
TAILQ_HEAD(processor_tbl, processor_entry);
@@ -82,65 +78,78 @@ static int32_t detected_processor_count;
/* sysctlbyname(hw.ncpu) */
static int hw_ncpu;
-/* sysctlbyname(kern.{ccpu,fscale}) */
-static fixpt_t ccpu;
-static int fscale;
-
-/* tick of PDU where we have refreshed the processor table last */
-static uint64_t proctbl_tick;
+/* sysctlbyname(kern.cp_times) */
+static int cpmib[2];
+static size_t cplen;
/* periodic timer used to get cpu load stats */
static void *cpus_load_timer;
-/*
- * Average the samples. The entire algorithm seems to be wrong XXX.
+/**
+ * Returns the CPU usage of a given processor entry.
+ *
+ * It needs at least two cp_times "tick" samples to calculate a delta and
+ * thus, the usage over the sampling period.
*/
static int
get_avg_load(struct processor_entry *e)
{
- u_int i;
- double sum = 0.0;
+ u_int i, oldest;
+ long delta = 0;
+ double usage = 0.0;
assert(e != NULL);
- if (e->sample_cnt == 0)
+ /* Need two samples to perform delta calculation. */
+ if (e->sample_cnt <= 1)
return (0);
- for (i = 0; i < e->sample_cnt; i++)
- sum += e->samples[i];
-
- return ((int)floor((double)sum/(double)e->sample_cnt));
-}
-
-/*
- * Stolen from /usr/src/bin/ps/print.c. The idle process should never
- * be swapped out :-)
- */
-static double
-processor_getpcpu(struct kinfo_proc *ki_p)
-{
-
- if (ccpu == 0 || fscale == 0)
- return (0.0);
-
-#define fxtofl(fixpt) ((double)(fixpt) / fscale)
- return (100.0 * fxtofl(ki_p->ki_pctcpu) /
- (1.0 - exp(ki_p->ki_swtime * log(fxtofl(ccpu)))));
+ /* Oldest usable index, we wrap around. */
+ if (e->sample_cnt == MAX_CPU_SAMPLES)
+ oldest = (e->cur_sample_idx + 1) % MAX_CPU_SAMPLES;
+ else
+ oldest = 0;
+
+ /* Sum delta for all states. */
+ for (i = 0; i < CPUSTATES; i++) {
+ delta += e->states[e->cur_sample_idx][i];
+ delta -= e->states[oldest][i];
+ }
+ if (delta == 0)
+ return 0;
+
+ /* Take idle time from the last element and convert to
+ * percent usage by contrasting with total ticks delta. */
+ usage = (double)(e->states[e->cur_sample_idx][CPUSTATES-1] -
+ e->states[oldest][CPUSTATES-1]) / delta;
+ usage = 100 - (usage * 100);
+ HRDBG("CPU no. %d, delta ticks %ld, pct usage %.2f", e->cpu_no,
+ delta, usage);
+
+ return ((int)(usage));
}
/**
- * Save a new sample
+ * Save a new sample to proc entry and get the average usage.
+ *
+ * Samples are stored in a ringbuffer from 0..(MAX_CPU_SAMPLES-1)
*/
static void
-save_sample(struct processor_entry *e, struct kinfo_proc *kp)
+save_sample(struct processor_entry *e, long *cp_times)
{
+ int i;
- e->samples[e->cur_sample_idx] = 100.0 - processor_getpcpu(kp);
- e->load = get_avg_load(e);
e->cur_sample_idx = (e->cur_sample_idx + 1) % MAX_CPU_SAMPLES;
+ for (i = 0; cp_times != NULL && i < CPUSTATES; i++)
+ e->states[e->cur_sample_idx][i] = cp_times[i];
- if (++e->sample_cnt > MAX_CPU_SAMPLES)
+ e->sample_cnt++;
+ if (e->sample_cnt > MAX_CPU_SAMPLES)
e->sample_cnt = MAX_CPU_SAMPLES;
+
+ HRDBG("sample count for CPU no. %d went to %d", e->cpu_no,
e->sample_cnt);
+ e->load = get_avg_load(e);
+
}
/**
@@ -178,8 +187,9 @@ proc_create_entry(u_int cpu_no, struct d
entry->index = map->hrIndex;
entry->load = 0;
+ entry->sample_cnt = 0;
+ entry->cur_sample_idx = -1;
entry->cpu_no = (u_char)cpu_no;
- entry->idle_pid = 0;
entry->frwId = &oid_zeroDotZero; /* unknown id FIXME */
INSERT_OBJECT_INT(entry, &processor_tbl);
@@ -191,64 +201,11 @@ proc_create_entry(u_int cpu_no, struct d
}
/**
- * Get the PIDs for the idle processes of the CPUs.
- */
-static void
-processor_get_pids(void)
-{
- struct kinfo_proc *plist, *kp;
- int i;
- int nproc;
- int cpu;
- int nchars;
- struct processor_entry *entry;
-
- plist = kvm_getprocs(hr_kd, KERN_PROC_ALL, 0, &nproc);
- if (plist == NULL || nproc < 0) {
- syslog(LOG_ERR, "hrProcessor: kvm_getprocs() failed: %m");
- return;
- }
-
- for (i = 0, kp = plist; i < nproc; i++, kp++) {
- if (!IS_KERNPROC(kp))
- continue;
-
- if (strcmp(kp->ki_comm, "idle") == 0) {
- /* single processor system */
- cpu = 0;
- } else if (sscanf(kp->ki_comm, "idle: cpu%d%n", &cpu, &nchars)
- == 1 && (u_int)nchars == strlen(kp->ki_comm)) {
- /* MP system */
- } else
- /* not an idle process */
- continue;
-
- HRDBG("'%s' proc with pid %d is on CPU #%d (last on #%d)",
- kp->ki_comm, kp->ki_pid, kp->ki_oncpu, kp->ki_lastcpu);
-
- TAILQ_FOREACH(entry, &processor_tbl, link)
- if (entry->cpu_no == kp->ki_lastcpu)
- break;
-
- if (entry == NULL) {
- /* create entry on non-ACPI systems */
- if ((entry = proc_create_entry(cpu, NULL)) == NULL)
- continue;
-
- detected_processor_count++;
- }
-
- entry->idle_pid = kp->ki_pid;
- HRDBG("CPU no. %d with SNMP index=%d has idle PID %d",
- entry->cpu_no, entry->index, entry->idle_pid);
-
- save_sample(entry, kp);
- }
-}
-
-/**
* Scan the device map table for CPUs and create an entry into the
- * processor table for each CPU. Then fetch the idle PIDs for all CPUs.
+ * processor table for each CPU.
+ *
+ * Make sure that the number of processors announced by the kernel hw.ncpu
+ * is equal to the number of processors we have found in the device table.
*/
static void
create_proc_table(void)
@@ -256,6 +213,7 @@ create_proc_table(void)
struct device_map_entry *map;
struct processor_entry *entry;
int cpu_no;
+ size_t len;
detected_processor_count = 0;
@@ -265,7 +223,7 @@ create_proc_table(void)
* If not, no entries will be present in the hrProcessor Table.
*
* For non-ACPI system the processors are not in the device table,
- * therefor insert them when getting the idle pids. XXX
+ * therefore insert them after checking hw.ncpu.
*/
STAILQ_FOREACH(map, &device_map, link)
if (strncmp(map->name_key, "cpu", strlen("cpu")) == 0 &&
@@ -283,9 +241,34 @@ create_proc_table(void)
detected_processor_count++;
}
- HRDBG("%d CPUs detected", detected_processor_count);
+ len = sizeof(hw_ncpu);
+ if (sysctlbyname("hw.ncpu", &hw_ncpu, &len, NULL, 0) == -1 ||
+ len != sizeof(hw_ncpu)) {
+ syslog(LOG_ERR, "hrProcessorTable: sysctl(hw.ncpu) failed");
+ hw_ncpu = 0;
+ }
+
+ HRDBG("%d CPUs detected via device table; hw.ncpu is %d",
+ detected_processor_count, hw_ncpu);
+
+ /* XXX Can happen on non-ACPI systems? Create entries by hand. */
+ for (; detected_processor_count < hw_ncpu; detected_processor_count++)
+ proc_create_entry(detected_processor_count, NULL);
+
+ len = 2;
+ if (sysctlnametomib("kern.cp_times", cpmib, &len)) {
+ syslog(LOG_ERR, "hrProcessorTable:
sysctlnametomib(kern.cp_times) failed");
+ cpmib[0] = 0;
+ cpmib[1] = 0;
+ cplen = 0;
+ } else if (sysctl(cpmib, 2, NULL, &len, NULL, 0)) {
+ syslog(LOG_ERR, "hrProcessorTable: sysctl(kern.cp_times) length
query failed");
+ cplen = 0;
+ } else {
+ cplen = len / sizeof(long);
+ }
+ HRDBG("%zu entries for kern.cp_times", cplen);
- processor_get_pids();
}
/**
@@ -307,78 +290,6 @@ free_proc_table(void)
}
/**
- * Init the things for hrProcessorTable.
- * Scan the device table for processor entries.
- */
-void
-init_processor_tbl(void)
-{
- size_t len;
-
- /* get various parameters from the kernel */
- len = sizeof(ccpu);
- if (sysctlbyname("kern.ccpu", &ccpu, &len, NULL, 0) == -1) {
- syslog(LOG_ERR, "hrProcessorTable: sysctl(kern.ccpu) failed");
- ccpu = 0;
- }
-
- len = sizeof(fscale);
- if (sysctlbyname("kern.fscale", &fscale, &len, NULL, 0) == -1) {
- syslog(LOG_ERR, "hrProcessorTable: sysctl(kern.fscale) failed");
- fscale = 0;
- }
-
- /* create the initial processor table */
- create_proc_table();
-}
-
-/**
- * Finalization routine for hrProcessorTable.
- * It destroys the lists and frees any allocated heap memory.
- */
-void
-fini_processor_tbl(void)
-{
-
- if (cpus_load_timer != NULL) {
- timer_stop(cpus_load_timer);
- cpus_load_timer = NULL;
- }
-
- free_proc_table();
-}
-
-/**
- * Make sure that the number of processors announced by the kernel hw.ncpu
- * is equal to the number of processors we have found in the device table.
- * If they differ rescan the device table.
- */
-static void
-processor_refill_tbl(void)
-{
-
- HRDBG("hw_ncpu=%d detected_processor_count=%d", hw_ncpu,
- detected_processor_count);
-
- if (hw_ncpu <= 0) {
- size_t size = sizeof(hw_ncpu);
-
- if (sysctlbyname("hw.ncpu", &hw_ncpu, &size, NULL, 0) == -1 ||
- size != sizeof(hw_ncpu)) {
- syslog(LOG_ERR, "hrProcessorTable: "
- "sysctl(hw.ncpu) failed: %m");
- hw_ncpu = 0;
- return;
- }
- }
-
- if (hw_ncpu != detected_processor_count) {
- free_proc_table();
- create_proc_table();
- }
-}
-
-/**
* Refresh all values in the processor table. We call this once for
* every PDU that accesses the table.
*/
@@ -386,37 +297,23 @@ static void
refresh_processor_tbl(void)
{
struct processor_entry *entry;
- int need_pids;
- struct kinfo_proc *plist;
- int nproc;
+ size_t size;
- processor_refill_tbl();
+ long pcpu_cp_times[cplen];
+ memset(pcpu_cp_times, 0, sizeof(pcpu_cp_times));
- need_pids = 0;
- TAILQ_FOREACH(entry, &processor_tbl, link) {
- if (entry->idle_pid <= 0) {
- need_pids = 1;
- continue;
- }
+ size = cplen * sizeof(long);
+ if (sysctl(cpmib, 2, pcpu_cp_times, &size, NULL, 0) == -1 &&
+ !(errno == ENOMEM && size >= cplen * sizeof(long))) {
+ syslog(LOG_ERR, "hrProcessorTable: sysctl(kern.cp_times)
failed");
+ return;
+ }
+ TAILQ_FOREACH(entry, &processor_tbl, link) {
assert(hr_kd != NULL);
-
- plist = kvm_getprocs(hr_kd, KERN_PROC_PID,
- entry->idle_pid, &nproc);
- if (plist == NULL || nproc != 1) {
- syslog(LOG_ERR, "%s: missing item with "
- "PID = %d for CPU #%d\n ", __func__,
- entry->idle_pid, entry->cpu_no);
- need_pids = 1;
- continue;
- }
- save_sample(entry, plist);
+ save_sample(entry, &pcpu_cp_times[entry->cpu_no * CPUSTATES]);
}
- if (need_pids == 1)
- processor_get_pids();
-
- proctbl_tick = this_tick;
}
/**
@@ -451,6 +348,36 @@ start_processor_tbl(struct lmodule *mod)
}
/**
+ * Init the things for hrProcessorTable.
+ * Scan the device table for processor entries.
+ */
+void
+init_processor_tbl(void)
+{
+
+ /* create the initial processor table */
+ create_proc_table();
+ /* and get first samples */
+ refresh_processor_tbl();
+}
+
+/**
+ * Finalization routine for hrProcessorTable.
+ * It destroys the lists and frees any allocated heap memory.
+ */
+void
+fini_processor_tbl(void)
+{
+
+ if (cpus_load_timer != NULL) {
+ timer_stop(cpus_load_timer);
+ cpus_load_timer = NULL;
+ }
+
+ free_proc_table();
+}
+
+/**
* Access routine for the processor table.
*/
int
@@ -460,9 +387,6 @@ op_hrProcessorTable(struct snmp_context
{
struct processor_entry *entry;
- if (this_tick != proctbl_tick)
- refresh_processor_tbl();
-
switch (curr_op) {
case SNMP_OP_GETNEXT:
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