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authorLinus Torvalds <torvalds@linux-foundation.org>2024-05-14 03:13:47 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2024-05-14 03:13:47 +0300
commit17ca7fc22f4bbc795e4d136449521b2fecb88e06 (patch)
treea1bee109d288772d04c4832109593e0e736fc6e3 /kernel
parent48fc82c40bc29a80361b1eab0e4a9494628a7144 (diff)
parent854dd99b5ddc9d90e31e5f112462a5994dd31810 (diff)
downloadlinux-17ca7fc22f4bbc795e4d136449521b2fecb88e06.tar.xz
Merge tag 'perf-core-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events updates from Ingo Molnar: - Combine perf and BPF for fast evalution of HW breakpoint conditions - Add LBR capture support outside of hardware events - Trigger IO signals for watermark_wakeup - Add RAPL support for Intel Arrow Lake and Lunar Lake - Optimize frequency-throttling - Miscellaneous cleanups & fixes * tag 'perf-core-2024-05-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) perf/bpf: Mark perf_event_set_bpf_handler() and perf_event_free_bpf_handler() as inline too selftests/perf_events: Test FASYNC with watermark wakeups perf/ring_buffer: Trigger IO signals for watermark_wakeup perf: Move perf_event_fasync() to perf_event.h perf/bpf: Change the !CONFIG_BPF_SYSCALL stubs to static inlines selftest/bpf: Test a perf BPF program that suppresses side effects perf/bpf: Allow a BPF program to suppress all sample side effects perf/bpf: Remove unneeded uses_default_overflow_handler() perf/bpf: Call BPF handler directly, not through overflow machinery perf/bpf: Remove #ifdef CONFIG_BPF_SYSCALL from struct perf_event members perf/bpf: Create bpf_overflow_handler() stub for !CONFIG_BPF_SYSCALL perf/bpf: Reorder bpf_overflow_handler() ahead of __perf_event_overflow() perf/x86/rapl: Add support for Intel Lunar Lake perf/x86/rapl: Add support for Intel Arrow Lake perf/core: Reduce PMU access to adjust sample freq perf/core: Optimize perf_adjust_freq_unthr_context() perf/x86/amd: Don't reject non-sampling events with configured LBR perf/x86/amd: Support capturing LBR from software events perf/x86/amd: Avoid taking branches before disabling LBR perf/x86/amd: Ensure amd_pmu_core_disable_all() is always inlined ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c273
-rw-r--r--kernel/events/ring_buffer.c4
2 files changed, 148 insertions, 129 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 724e6d7e128f..6b0a66ed2ae3 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2302,8 +2302,10 @@ event_sched_out(struct perf_event *event, struct perf_event_context *ctx)
if (!is_software_event(event))
cpc->active_oncpu--;
- if (event->attr.freq && event->attr.sample_freq)
+ if (event->attr.freq && event->attr.sample_freq) {
ctx->nr_freq--;
+ epc->nr_freq--;
+ }
if (event->attr.exclusive || !cpc->active_oncpu)
cpc->exclusive = 0;
@@ -2558,9 +2560,10 @@ event_sched_in(struct perf_event *event, struct perf_event_context *ctx)
if (!is_software_event(event))
cpc->active_oncpu++;
- if (event->attr.freq && event->attr.sample_freq)
+ if (event->attr.freq && event->attr.sample_freq) {
ctx->nr_freq++;
-
+ epc->nr_freq++;
+ }
if (event->attr.exclusive)
cpc->exclusive = 1;
@@ -4123,30 +4126,14 @@ static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bo
}
}
-/*
- * combine freq adjustment with unthrottling to avoid two passes over the
- * events. At the same time, make sure, having freq events does not change
- * the rate of unthrottling as that would introduce bias.
- */
-static void
-perf_adjust_freq_unthr_context(struct perf_event_context *ctx, bool unthrottle)
+static void perf_adjust_freq_unthr_events(struct list_head *event_list)
{
struct perf_event *event;
struct hw_perf_event *hwc;
u64 now, period = TICK_NSEC;
s64 delta;
- /*
- * only need to iterate over all events iff:
- * - context have events in frequency mode (needs freq adjust)
- * - there are events to unthrottle on this cpu
- */
- if (!(ctx->nr_freq || unthrottle))
- return;
-
- raw_spin_lock(&ctx->lock);
-
- list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+ list_for_each_entry(event, event_list, active_list) {
if (event->state != PERF_EVENT_STATE_ACTIVE)
continue;
@@ -4154,18 +4141,17 @@ perf_adjust_freq_unthr_context(struct perf_event_context *ctx, bool unthrottle)
if (!event_filter_match(event))
continue;
- perf_pmu_disable(event->pmu);
-
hwc = &event->hw;
if (hwc->interrupts == MAX_INTERRUPTS) {
hwc->interrupts = 0;
perf_log_throttle(event, 1);
- event->pmu->start(event, 0);
+ if (!event->attr.freq || !event->attr.sample_freq)
+ event->pmu->start(event, 0);
}
if (!event->attr.freq || !event->attr.sample_freq)
- goto next;
+ continue;
/*
* stop the event and update event->count
@@ -4187,8 +4173,41 @@ perf_adjust_freq_unthr_context(struct perf_event_context *ctx, bool unthrottle)
perf_adjust_period(event, period, delta, false);
event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
- next:
- perf_pmu_enable(event->pmu);
+ }
+}
+
+/*
+ * combine freq adjustment with unthrottling to avoid two passes over the
+ * events. At the same time, make sure, having freq events does not change
+ * the rate of unthrottling as that would introduce bias.
+ */
+static void
+perf_adjust_freq_unthr_context(struct perf_event_context *ctx, bool unthrottle)
+{
+ struct perf_event_pmu_context *pmu_ctx;
+
+ /*
+ * only need to iterate over all events iff:
+ * - context have events in frequency mode (needs freq adjust)
+ * - there are events to unthrottle on this cpu
+ */
+ if (!(ctx->nr_freq || unthrottle))
+ return;
+
+ raw_spin_lock(&ctx->lock);
+
+ list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
+ if (!(pmu_ctx->nr_freq || unthrottle))
+ continue;
+ if (!perf_pmu_ctx_is_active(pmu_ctx))
+ continue;
+ if (pmu_ctx->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT)
+ continue;
+
+ perf_pmu_disable(pmu_ctx->pmu);
+ perf_adjust_freq_unthr_events(&pmu_ctx->pinned_active);
+ perf_adjust_freq_unthr_events(&pmu_ctx->flexible_active);
+ perf_pmu_enable(pmu_ctx->pmu);
}
raw_spin_unlock(&ctx->lock);
@@ -6684,14 +6703,6 @@ static const struct file_operations perf_fops = {
* to user-space before waking everybody up.
*/
-static inline struct fasync_struct **perf_event_fasync(struct perf_event *event)
-{
- /* only the parent has fasync state */
- if (event->parent)
- event = event->parent;
- return &event->fasync;
-}
-
void perf_event_wakeup(struct perf_event *event)
{
ring_buffer_wakeup(event);
@@ -9544,6 +9555,100 @@ static inline bool sample_is_allowed(struct perf_event *event, struct pt_regs *r
return true;
}
+#ifdef CONFIG_BPF_SYSCALL
+static int bpf_overflow_handler(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ struct bpf_perf_event_data_kern ctx = {
+ .data = data,
+ .event = event,
+ };
+ struct bpf_prog *prog;
+ int ret = 0;
+
+ ctx.regs = perf_arch_bpf_user_pt_regs(regs);
+ if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
+ goto out;
+ rcu_read_lock();
+ prog = READ_ONCE(event->prog);
+ if (prog) {
+ perf_prepare_sample(data, event, regs);
+ ret = bpf_prog_run(prog, &ctx);
+ }
+ rcu_read_unlock();
+out:
+ __this_cpu_dec(bpf_prog_active);
+
+ return ret;
+}
+
+static inline int perf_event_set_bpf_handler(struct perf_event *event,
+ struct bpf_prog *prog,
+ u64 bpf_cookie)
+{
+ if (event->overflow_handler_context)
+ /* hw breakpoint or kernel counter */
+ return -EINVAL;
+
+ if (event->prog)
+ return -EEXIST;
+
+ if (prog->type != BPF_PROG_TYPE_PERF_EVENT)
+ return -EINVAL;
+
+ if (event->attr.precise_ip &&
+ prog->call_get_stack &&
+ (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) ||
+ event->attr.exclude_callchain_kernel ||
+ event->attr.exclude_callchain_user)) {
+ /*
+ * On perf_event with precise_ip, calling bpf_get_stack()
+ * may trigger unwinder warnings and occasional crashes.
+ * bpf_get_[stack|stackid] works around this issue by using
+ * callchain attached to perf_sample_data. If the
+ * perf_event does not full (kernel and user) callchain
+ * attached to perf_sample_data, do not allow attaching BPF
+ * program that calls bpf_get_[stack|stackid].
+ */
+ return -EPROTO;
+ }
+
+ event->prog = prog;
+ event->bpf_cookie = bpf_cookie;
+ return 0;
+}
+
+static inline void perf_event_free_bpf_handler(struct perf_event *event)
+{
+ struct bpf_prog *prog = event->prog;
+
+ if (!prog)
+ return;
+
+ event->prog = NULL;
+ bpf_prog_put(prog);
+}
+#else
+static inline int bpf_overflow_handler(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ return 1;
+}
+
+static inline int perf_event_set_bpf_handler(struct perf_event *event,
+ struct bpf_prog *prog,
+ u64 bpf_cookie)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline void perf_event_free_bpf_handler(struct perf_event *event)
+{
+}
+#endif
+
/*
* Generic event overflow handling, sampling.
*/
@@ -9564,6 +9669,9 @@ static int __perf_event_overflow(struct perf_event *event,
ret = __perf_event_account_interrupt(event, throttle);
+ if (event->prog && !bpf_overflow_handler(event, data, regs))
+ return ret;
+
/*
* XXX event_limit might not quite work as expected on inherited
* events
@@ -10422,97 +10530,6 @@ static void perf_event_free_filter(struct perf_event *event)
ftrace_profile_free_filter(event);
}
-#ifdef CONFIG_BPF_SYSCALL
-static void bpf_overflow_handler(struct perf_event *event,
- struct perf_sample_data *data,
- struct pt_regs *regs)
-{
- struct bpf_perf_event_data_kern ctx = {
- .data = data,
- .event = event,
- };
- struct bpf_prog *prog;
- int ret = 0;
-
- ctx.regs = perf_arch_bpf_user_pt_regs(regs);
- if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
- goto out;
- rcu_read_lock();
- prog = READ_ONCE(event->prog);
- if (prog) {
- perf_prepare_sample(data, event, regs);
- ret = bpf_prog_run(prog, &ctx);
- }
- rcu_read_unlock();
-out:
- __this_cpu_dec(bpf_prog_active);
- if (!ret)
- return;
-
- event->orig_overflow_handler(event, data, regs);
-}
-
-static int perf_event_set_bpf_handler(struct perf_event *event,
- struct bpf_prog *prog,
- u64 bpf_cookie)
-{
- if (event->overflow_handler_context)
- /* hw breakpoint or kernel counter */
- return -EINVAL;
-
- if (event->prog)
- return -EEXIST;
-
- if (prog->type != BPF_PROG_TYPE_PERF_EVENT)
- return -EINVAL;
-
- if (event->attr.precise_ip &&
- prog->call_get_stack &&
- (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) ||
- event->attr.exclude_callchain_kernel ||
- event->attr.exclude_callchain_user)) {
- /*
- * On perf_event with precise_ip, calling bpf_get_stack()
- * may trigger unwinder warnings and occasional crashes.
- * bpf_get_[stack|stackid] works around this issue by using
- * callchain attached to perf_sample_data. If the
- * perf_event does not full (kernel and user) callchain
- * attached to perf_sample_data, do not allow attaching BPF
- * program that calls bpf_get_[stack|stackid].
- */
- return -EPROTO;
- }
-
- event->prog = prog;
- event->bpf_cookie = bpf_cookie;
- event->orig_overflow_handler = READ_ONCE(event->overflow_handler);
- WRITE_ONCE(event->overflow_handler, bpf_overflow_handler);
- return 0;
-}
-
-static void perf_event_free_bpf_handler(struct perf_event *event)
-{
- struct bpf_prog *prog = event->prog;
-
- if (!prog)
- return;
-
- WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler);
- event->prog = NULL;
- bpf_prog_put(prog);
-}
-#else
-static int perf_event_set_bpf_handler(struct perf_event *event,
- struct bpf_prog *prog,
- u64 bpf_cookie)
-{
- return -EOPNOTSUPP;
-}
-static void perf_event_free_bpf_handler(struct perf_event *event)
-{
-}
-#endif
-
/*
* returns true if the event is a tracepoint, or a kprobe/upprobe created
* with perf_event_open()
@@ -11971,13 +11988,11 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
overflow_handler = parent_event->overflow_handler;
context = parent_event->overflow_handler_context;
#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
- if (overflow_handler == bpf_overflow_handler) {
+ if (parent_event->prog) {
struct bpf_prog *prog = parent_event->prog;
bpf_prog_inc(prog);
event->prog = prog;
- event->orig_overflow_handler =
- parent_event->orig_overflow_handler;
}
#endif
}
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 60ed43d1c29e..4013408ce012 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -22,6 +22,10 @@ static void perf_output_wakeup(struct perf_output_handle *handle)
atomic_set(&handle->rb->poll, EPOLLIN);
handle->event->pending_wakeup = 1;
+
+ if (*perf_event_fasync(handle->event) && !handle->event->pending_kill)
+ handle->event->pending_kill = POLL_IN;
+
irq_work_queue(&handle->event->pending_irq);
}