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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-06-11 11:25:05 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-06-11 16:48:38 +0200 |
| commit | df58ab24bf26b166874bfb18b3b5a2e0a8e63179 (patch) | |
| tree | 388b2fb9d94864c9bd6d6ab9329c31760b7366ae | |
| parent | 0764771dab80d7b84b9a271bee7f1b21a04a3f0c (diff) | |
| download | linux-df58ab24bf26b166874bfb18b3b5a2e0a8e63179.tar.gz linux-df58ab24bf26b166874bfb18b3b5a2e0a8e63179.tar.bz2 linux-df58ab24bf26b166874bfb18b3b5a2e0a8e63179.zip | |
perf_counter: Rename perf_counter_limit sysctl
Rename perf_counter_limit to perf_counter_max_sample_rate and
prohibit creation of counters with a known higher sample
frequency.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/perf_counter.h | 2 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 27 | ||||
| -rw-r--r-- | kernel/sysctl.c | 6 |
3 files changed, 23 insertions, 12 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 386be915baa1..95c797c480e8 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -650,7 +650,7 @@ extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs); extern int sysctl_perf_counter_paranoid; extern int sysctl_perf_counter_mlock; -extern int sysctl_perf_counter_limit; +extern int sysctl_perf_counter_sample_rate; extern void perf_counter_init(void); diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 63f1987c1c1c..3b2829de5590 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -44,11 +44,12 @@ static atomic_t nr_mmap_counters __read_mostly; static atomic_t nr_comm_counters __read_mostly; /* - * 0 - not paranoid - * 1 - disallow cpu counters to unpriv - * 2 - disallow kernel profiling to unpriv + * perf counter paranoia level: + * 0 - not paranoid + * 1 - disallow cpu counters to unpriv + * 2 - disallow kernel profiling to unpriv */ -int sysctl_perf_counter_paranoid __read_mostly; /* do we need to be privileged */ +int sysctl_perf_counter_paranoid __read_mostly; static inline bool perf_paranoid_cpu(void) { @@ -61,7 +62,11 @@ static inline bool perf_paranoid_kernel(void) } int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */ -int sysctl_perf_counter_limit __read_mostly = 100000; /* max NMIs per second */ + +/* + * max perf counter sample rate + */ +int sysctl_perf_counter_sample_rate __read_mostly = 100000; static atomic64_t perf_counter_id; @@ -1244,7 +1249,7 @@ static void perf_ctx_adjust_freq(struct perf_counter_context *ctx) if (interrupts == MAX_INTERRUPTS) { perf_log_throttle(counter, 1); counter->pmu->unthrottle(counter); - interrupts = 2*sysctl_perf_counter_limit/HZ; + interrupts = 2*sysctl_perf_counter_sample_rate/HZ; } if (!counter->attr.freq || !counter->attr.sample_freq) @@ -1682,7 +1687,7 @@ static int perf_counter_period(struct perf_counter *counter, u64 __user *arg) spin_lock_irq(&ctx->lock); if (counter->attr.freq) { - if (value > sysctl_perf_counter_limit) { + if (value > sysctl_perf_counter_sample_rate) { ret = -EINVAL; goto unlock; } @@ -2979,7 +2984,8 @@ int perf_counter_overflow(struct perf_counter *counter, int nmi, } else { if (hwc->interrupts != MAX_INTERRUPTS) { hwc->interrupts++; - if (HZ * hwc->interrupts > (u64)sysctl_perf_counter_limit) { + if (HZ * hwc->interrupts > + (u64)sysctl_perf_counter_sample_rate) { hwc->interrupts = MAX_INTERRUPTS; perf_log_throttle(counter, 0); ret = 1; @@ -3639,6 +3645,11 @@ SYSCALL_DEFINE5(perf_counter_open, return -EACCES; } + if (attr.freq) { + if (attr.sample_freq > sysctl_perf_counter_sample_rate) + return -EINVAL; + } + /* * Get the target context (task or percpu): */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 344a65981dee..9fd4e436b696 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -932,9 +932,9 @@ static struct ctl_table kern_table[] = { }, { .ctl_name = CTL_UNNUMBERED, - .procname = "perf_counter_int_limit", - .data = &sysctl_perf_counter_limit, - .maxlen = sizeof(sysctl_perf_counter_limit), + .procname = "perf_counter_max_sample_rate", + .data = &sysctl_perf_counter_sample_rate, + .maxlen = sizeof(sysctl_perf_counter_sample_rate), .mode = 0644, .proc_handler = &proc_dointvec, }, |