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-rw-r--r--arch/x86/kernel/cpu/perf_event.c83
-rw-r--r--arch/x86/kernel/cpu/perf_event.h24
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel.c45
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_ds.c4
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_pt.c36
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_uncore.c9
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_uncore.h1
-rw-r--r--include/linux/perf_event.h4
-rw-r--r--kernel/events/core.c3
-rw-r--r--kernel/events/ring_buffer.c14
10 files changed, 139 insertions, 84 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 87848eb..4f7001f 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -190,6 +190,7 @@ static bool check_hw_exists(void)
u64 val, val_fail, val_new= ~0;
int i, reg, reg_fail, ret = 0;
int bios_fail = 0;
+ int reg_safe = -1;
/*
* Check to see if the BIOS enabled any of the counters, if so
@@ -204,6 +205,8 @@ static bool check_hw_exists(void)
bios_fail = 1;
val_fail = val;
reg_fail = reg;
+ } else {
+ reg_safe = i;
}
}
@@ -222,11 +225,22 @@ static bool check_hw_exists(void)
}
/*
+ * If all the counters are enabled, the below test will always
+ * fail. The tools will also become useless in this scenario.
+ * Just fail and disable the hardware counters.
+ */
+
+ if (reg_safe == -1) {
+ reg = reg_safe;
+ goto msr_fail;
+ }
+
+ /*
* Read the current value, change it and read it back to see if it
* matches, this is needed to detect certain hardware emulators
* (qemu/kvm) that don't trap on the MSR access and always return 0s.
*/
- reg = x86_pmu_event_addr(0);
+ reg = x86_pmu_event_addr(reg_safe);
if (rdmsrl_safe(reg, &val))
goto msr_fail;
val ^= 0xffffUL;
@@ -611,6 +625,7 @@ struct sched_state {
int event; /* event index */
int counter; /* counter index */
int unassigned; /* number of events to be assigned left */
+ int nr_gp; /* number of GP counters used */
unsigned long used[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
};
@@ -620,27 +635,29 @@ struct sched_state {
struct perf_sched {
int max_weight;
int max_events;
- struct perf_event **events;
- struct sched_state state;
+ int max_gp;
int saved_states;
+ struct event_constraint **constraints;
+ struct sched_state state;
struct sched_state saved[SCHED_STATES_MAX];
};
/*
* Initialize interator that runs through all events and counters.
*/
-static void perf_sched_init(struct perf_sched *sched, struct perf_event **events,
- int num, int wmin, int wmax)
+static void perf_sched_init(struct perf_sched *sched, struct event_constraint **constraints,
+ int num, int wmin, int wmax, int gpmax)
{
int idx;
memset(sched, 0, sizeof(*sched));
sched->max_events = num;
sched->max_weight = wmax;
- sched->events = events;
+ sched->max_gp = gpmax;
+ sched->constraints = constraints;
for (idx = 0; idx < num; idx++) {
- if (events[idx]->hw.constraint->weight == wmin)
+ if (constraints[idx]->weight == wmin)
break;
}
@@ -687,7 +704,7 @@ static bool __perf_sched_find_counter(struct perf_sched *sched)
if (sched->state.event >= sched->max_events)
return false;
- c = sched->events[sched->state.event]->hw.constraint;
+ c = sched->constraints[sched->state.event];
/* Prefer fixed purpose counters */
if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) {
idx = INTEL_PMC_IDX_FIXED;
@@ -696,11 +713,16 @@ static bool __perf_sched_find_counter(struct perf_sched *sched)
goto done;
}
}
+
/* Grab the first unused counter starting with idx */
idx = sched->state.counter;
for_each_set_bit_from(idx, c->idxmsk, INTEL_PMC_IDX_FIXED) {
- if (!__test_and_set_bit(idx, sched->state.used))
+ if (!__test_and_set_bit(idx, sched->state.used)) {
+ if (sched->state.nr_gp++ >= sched->max_gp)
+ return false;
+
goto done;
+ }
}
return false;
@@ -745,7 +767,7 @@ static bool perf_sched_next_event(struct perf_sched *sched)
if (sched->state.weight > sched->max_weight)
return false;
}
- c = sched->events[sched->state.event]->hw.constraint;
+ c = sched->constraints[sched->state.event];
} while (c->weight != sched->state.weight);
sched->state.counter = 0; /* start with first counter */
@@ -756,12 +778,12 @@ static bool perf_sched_next_event(struct perf_sched *sched)
/*
* Assign a counter for each event.
*/
-int perf_assign_events(struct perf_event **events, int n,
- int wmin, int wmax, int *assign)
+int perf_assign_events(struct event_constraint **constraints, int n,
+ int wmin, int wmax, int gpmax, int *assign)
{
struct perf_sched sched;
- perf_sched_init(&sched, events, n, wmin, wmax);
+ perf_sched_init(&sched, constraints, n, wmin, wmax, gpmax);
do {
if (!perf_sched_find_counter(&sched))
@@ -788,9 +810,9 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
x86_pmu.start_scheduling(cpuc);
for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
- hwc = &cpuc->event_list[i]->hw;
+ cpuc->event_constraint[i] = NULL;
c = x86_pmu.get_event_constraints(cpuc, i, cpuc->event_list[i]);
- hwc->constraint = c;
+ cpuc->event_constraint[i] = c;
wmin = min(wmin, c->weight);
wmax = max(wmax, c->weight);
@@ -801,7 +823,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
*/
for (i = 0; i < n; i++) {
hwc = &cpuc->event_list[i]->hw;
- c = hwc->constraint;
+ c = cpuc->event_constraint[i];
/* never assigned */
if (hwc->idx == -1)
@@ -821,9 +843,26 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
}
/* slow path */
- if (i != n)
- unsched = perf_assign_events(cpuc->event_list, n, wmin,
- wmax, assign);
+ if (i != n) {
+ int gpmax = x86_pmu.num_counters;
+
+ /*
+ * Do not allow scheduling of more than half the available
+ * generic counters.
+ *
+ * This helps avoid counter starvation of sibling thread by
+ * ensuring at most half the counters cannot be in exclusive
+ * mode. There is no designated counters for the limits. Any
+ * N/2 counters can be used. This helps with events with
+ * specific counter constraints.
+ */
+ if (is_ht_workaround_enabled() && !cpuc->is_fake &&
+ READ_ONCE(cpuc->excl_cntrs->exclusive_present))
+ gpmax /= 2;
+
+ unsched = perf_assign_events(cpuc->event_constraint, n, wmin,
+ wmax, gpmax, assign);
+ }
/*
* In case of success (unsched = 0), mark events as committed,
@@ -840,7 +879,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
e = cpuc->event_list[i];
e->hw.flags |= PERF_X86_EVENT_COMMITTED;
if (x86_pmu.commit_scheduling)
- x86_pmu.commit_scheduling(cpuc, e, assign[i]);
+ x86_pmu.commit_scheduling(cpuc, i, assign[i]);
}
}
@@ -1292,8 +1331,10 @@ static void x86_pmu_del(struct perf_event *event, int flags)
x86_pmu.put_event_constraints(cpuc, event);
/* Delete the array entry. */
- while (++i < cpuc->n_events)
+ while (++i < cpuc->n_events) {
cpuc->event_list[i-1] = cpuc->event_list[i];
+ cpuc->event_constraint[i-1] = cpuc->event_constraint[i];
+ }
--cpuc->n_events;
perf_event_update_userpage(event);
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 6ac5cb7..ef78516 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -74,6 +74,7 @@ struct event_constraint {
#define PERF_X86_EVENT_EXCL 0x0040 /* HT exclusivity on counter */
#define PERF_X86_EVENT_DYNAMIC 0x0080 /* dynamic alloc'd constraint */
#define PERF_X86_EVENT_RDPMC_ALLOWED 0x0100 /* grant rdpmc permission */
+#define PERF_X86_EVENT_EXCL_ACCT 0x0200 /* accounted EXCL event */
struct amd_nb {
@@ -134,8 +135,6 @@ enum intel_excl_state_type {
struct intel_excl_states {
enum intel_excl_state_type init_state[X86_PMC_IDX_MAX];
enum intel_excl_state_type state[X86_PMC_IDX_MAX];
- int num_alloc_cntrs;/* #counters allocated */
- int max_alloc_cntrs;/* max #counters allowed */
bool sched_started; /* true if scheduling has started */
};
@@ -144,6 +143,11 @@ struct intel_excl_cntrs {
struct intel_excl_states states[2];
+ union {
+ u16 has_exclusive[2];
+ u32 exclusive_present;
+ };
+
int refcnt; /* per-core: #HT threads */
unsigned core_id; /* per-core: core id */
};
@@ -172,7 +176,11 @@ struct cpu_hw_events {
added in the current transaction */
int assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
u64 tags[X86_PMC_IDX_MAX];
+
struct perf_event *event_list[X86_PMC_IDX_MAX]; /* in enabled order */
+ struct event_constraint *event_constraint[X86_PMC_IDX_MAX];
+
+ int n_excl; /* the number of exclusive events */
unsigned int group_flag;
int is_fake;
@@ -519,9 +527,7 @@ struct x86_pmu {
void (*put_event_constraints)(struct cpu_hw_events *cpuc,
struct perf_event *event);
- void (*commit_scheduling)(struct cpu_hw_events *cpuc,
- struct perf_event *event,
- int cntr);
+ void (*commit_scheduling)(struct cpu_hw_events *cpuc, int idx, int cntr);
void (*start_scheduling)(struct cpu_hw_events *cpuc);
@@ -717,8 +723,8 @@ static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc,
void x86_pmu_enable_all(int added);
-int perf_assign_events(struct perf_event **events, int n,
- int wmin, int wmax, int *assign);
+int perf_assign_events(struct event_constraint **constraints, int n,
+ int wmin, int wmax, int gpmax, int *assign);
int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign);
void x86_pmu_stop(struct perf_event *event, int flags);
@@ -929,4 +935,8 @@ static inline struct intel_shared_regs *allocate_shared_regs(int cpu)
return NULL;
}
+static inline int is_ht_workaround_enabled(void)
+{
+ return 0;
+}
#endif /* CONFIG_CPU_SUP_INTEL */
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 3998131..a1e35c9 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1923,7 +1923,6 @@ intel_start_scheduling(struct cpu_hw_events *cpuc)
xl = &excl_cntrs->states[tid];
xl->sched_started = true;
- xl->num_alloc_cntrs = 0;
/*
* lock shared state until we are done scheduling
* in stop_event_scheduling()
@@ -2000,6 +1999,11 @@ intel_get_excl_constraints(struct cpu_hw_events *cpuc, struct perf_event *event,
* across HT threads
*/
is_excl = c->flags & PERF_X86_EVENT_EXCL;
+ if (is_excl && !(event->hw.flags & PERF_X86_EVENT_EXCL_ACCT)) {
+ event->hw.flags |= PERF_X86_EVENT_EXCL_ACCT;
+ if (!cpuc->n_excl++)
+ WRITE_ONCE(excl_cntrs->has_exclusive[tid], 1);
+ }
/*
* xl = state of current HT
@@ -2008,18 +2012,6 @@ intel_get_excl_constraints(struct cpu_hw_events *cpuc, struct perf_event *event,
xl = &excl_cntrs->states[tid];
xlo = &excl_cntrs->states[o_tid];
- /*
- * do not allow scheduling of more than max_alloc_cntrs
- * which is set to half the available generic counters.
- * this helps avoid counter starvation of sibling thread
- * by ensuring at most half the counters cannot be in
- * exclusive mode. There is not designated counters for the
- * limits. Any N/2 counters can be used. This helps with
- * events with specifix counter constraints
- */
- if (xl->num_alloc_cntrs++ == xl->max_alloc_cntrs)
- return &emptyconstraint;
-
cx = c;
/*
@@ -2106,7 +2098,7 @@ static struct event_constraint *
intel_get_event_constraints(struct cpu_hw_events *cpuc, int idx,
struct perf_event *event)
{
- struct event_constraint *c1 = event->hw.constraint;
+ struct event_constraint *c1 = cpuc->event_constraint[idx];
struct event_constraint *c2;
/*
@@ -2150,6 +2142,11 @@ static void intel_put_excl_constraints(struct cpu_hw_events *cpuc,
xl = &excl_cntrs->states[tid];
xlo = &excl_cntrs->states[o_tid];
+ if (hwc->flags & PERF_X86_EVENT_EXCL_ACCT) {
+ hwc->flags &= ~PERF_X86_EVENT_EXCL_ACCT;
+ if (!--cpuc->n_excl)
+ WRITE_ONCE(excl_cntrs->has_exclusive[tid], 0);
+ }
/*
* put_constraint may be called from x86_schedule_events()
@@ -2188,8 +2185,6 @@ intel_put_shared_regs_event_constraints(struct cpu_hw_events *cpuc,
static void intel_put_event_constraints(struct cpu_hw_events *cpuc,
struct perf_event *event)
{
- struct event_constraint *c = event->hw.constraint;
-
intel_put_shared_regs_event_constraints(cpuc, event);
/*
@@ -2197,19 +2192,14 @@ static void intel_put_event_constraints(struct cpu_hw_events *cpuc,
* all events are subject to and must call the
* put_excl_constraints() routine
*/
- if (c && cpuc->excl_cntrs)
+ if (cpuc->excl_cntrs)
intel_put_excl_constraints(cpuc, event);
-
- /* cleanup dynamic constraint */
- if (c && (c->flags & PERF_X86_EVENT_DYNAMIC))
- event->hw.constraint = NULL;
}
-static void intel_commit_scheduling(struct cpu_hw_events *cpuc,
- struct perf_event *event, int cntr)
+static void intel_commit_scheduling(struct cpu_hw_events *cpuc, int idx, int cntr)
{
struct intel_excl_cntrs *excl_cntrs = cpuc->excl_cntrs;
- struct event_constraint *c = event->hw.constraint;
+ struct event_constraint *c = cpuc->event_constraint[idx];
struct intel_excl_states *xlo, *xl;
int tid = cpuc->excl_thread_id;
int o_tid = 1 - tid;
@@ -2639,8 +2629,6 @@ static void intel_pmu_cpu_starting(int cpu)
cpuc->lbr_sel = &cpuc->shared_regs->regs[EXTRA_REG_LBR];
if (x86_pmu.flags & PMU_FL_EXCL_CNTRS) {
- int h = x86_pmu.num_counters >> 1;
-
for_each_cpu(i, topology_thread_cpumask(cpu)) {
struct intel_excl_cntrs *c;
@@ -2654,11 +2642,6 @@ static void intel_pmu_cpu_starting(int cpu)
}
cpuc->excl_cntrs->core_id = core_id;
cpuc->excl_cntrs->refcnt++;
- /*
- * set hard limit to half the number of generic counters
- */
- cpuc->excl_cntrs->states[0].max_alloc_cntrs = h;
- cpuc->excl_cntrs->states[1].max_alloc_cntrs = h;
}
}
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 813f75d..7f73b35 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -706,9 +706,9 @@ void intel_pmu_pebs_disable(struct perf_event *event)
cpuc->pebs_enabled &= ~(1ULL << hwc->idx);
- if (event->hw.constraint->flags & PERF_X86_EVENT_PEBS_LDLAT)
+ if (event->hw.flags & PERF_X86_EVENT_PEBS_LDLAT)
cpuc->pebs_enabled &= ~(1ULL << (hwc->idx + 32));
- else if (event->hw.constraint->flags & PERF_X86_EVENT_PEBS_ST)
+ else if (event->hw.flags & PERF_X86_EVENT_PEBS_ST)
cpuc->pebs_enabled &= ~(1ULL << 63);
if (cpuc->enabled)
diff --git a/arch/x86/kernel/cpu/perf_event_intel_pt.c b/arch/x86/kernel/cpu/perf_event_intel_pt.c
index ffe666c..123ff1b 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_pt.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_pt.c
@@ -151,7 +151,7 @@ static int __init pt_pmu_hw_init(void)
de_attr->attr.attr.name = pt_caps[i].name;
- sysfs_attr_init(&de_attrs->attr.attr);
+ sysfs_attr_init(&de_attr->attr.attr);
de_attr->attr.attr.mode = S_IRUGO;
de_attr->attr.show = pt_cap_show;
@@ -615,7 +615,8 @@ static int pt_buffer_reset_markers(struct pt_buffer *buf,
struct perf_output_handle *handle)
{
- unsigned long idx, npages, end;
+ unsigned long head = local64_read(&buf->head);
+ unsigned long idx, npages, wakeup;
if (buf->snapshot)
return 0;
@@ -634,17 +635,26 @@ static int pt_buffer_reset_markers(struct pt_buffer *buf,
buf->topa_index[buf->stop_pos]->stop = 0;
buf->topa_index[buf->intr_pos]->intr = 0;
- if (pt_cap_get(PT_CAP_topa_multiple_entries)) {
- npages = (handle->size + 1) >> PAGE_SHIFT;
- end = (local64_read(&buf->head) >> PAGE_SHIFT) + npages;
- /*if (end > handle->wakeup >> PAGE_SHIFT)
- end = handle->wakeup >> PAGE_SHIFT;*/
- idx = end & (buf->nr_pages - 1);
- buf->stop_pos = idx;
- idx = (local64_read(&buf->head) >> PAGE_SHIFT) + npages - 1;
- idx &= buf->nr_pages - 1;
- buf->intr_pos = idx;
- }
+ /* how many pages till the STOP marker */
+ npages = handle->size >> PAGE_SHIFT;
+
+ /* if it's on a page boundary, fill up one more page */
+ if (!offset_in_page(head + handle->size + 1))
+ npages++;
+
+ idx = (head >> PAGE_SHIFT) + npages;
+ idx &= buf->nr_pages - 1;
+ buf->stop_pos = idx;
+
+ wakeup = handle->wakeup >> PAGE_SHIFT;
+
+ /* in the worst case, wake up the consumer one page before hard stop */
+ idx = (head >> PAGE_SHIFT) + npages - 1;
+ if (idx > wakeup)
+ idx = wakeup;
+
+ idx &= buf->nr_pages - 1;
+ buf->intr_pos = idx;
buf->topa_index[buf->stop_pos]->stop = 1;
buf->topa_index[buf->intr_pos]->intr = 1;
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
index c635b8b..dd319e5 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -365,9 +365,8 @@ static int uncore_assign_events(struct intel_uncore_box *box, int assign[], int
bitmap_zero(used_mask, UNCORE_PMC_IDX_MAX);
for (i = 0, wmin = UNCORE_PMC_IDX_MAX, wmax = 0; i < n; i++) {
- hwc = &box->event_list[i]->hw;
c = uncore_get_event_constraint(box, box->event_list[i]);
- hwc->constraint = c;
+ box->event_constraint[i] = c;
wmin = min(wmin, c->weight);
wmax = max(wmax, c->weight);
}
@@ -375,7 +374,7 @@ static int uncore_assign_events(struct intel_uncore_box *box, int assign[], int
/* fastpath, try to reuse previous register */
for (i = 0; i < n; i++) {
hwc = &box->event_list[i]->hw;
- c = hwc->constraint;
+ c = box->event_constraint[i];
/* never assigned */
if (hwc->idx == -1)
@@ -395,8 +394,8 @@ static int uncore_assign_events(struct intel_uncore_box *box, int assign[], int
}
/* slow path */
if (i != n)
- ret = perf_assign_events(box->event_list, n,
- wmin, wmax, assign);
+ ret = perf_assign_events(box->event_constraint, n,
+ wmin, wmax, n, assign);
if (!assign || ret) {
for (i = 0; i < n; i++)
diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.h b/arch/x86/kernel/cpu/perf_event_intel_uncore.h
index 6c8c1e7..f789ec9 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.h
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.h
@@ -97,6 +97,7 @@ struct intel_uncore_box {
atomic_t refcnt;
struct perf_event *events[UNCORE_PMC_IDX_MAX];
struct perf_event *event_list[UNCORE_PMC_IDX_MAX];
+ struct event_constraint *event_constraint[UNCORE_PMC_IDX_MAX];
unsigned long active_mask[BITS_TO_LONGS(UNCORE_PMC_IDX_MAX)];
u64 tags[UNCORE_PMC_IDX_MAX];
struct pci_dev *pci_dev;
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 61992cf..d8a82a8 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -92,8 +92,6 @@ struct hw_perf_event_extra {
int idx; /* index in shared_regs->regs[] */
};
-struct event_constraint;
-
/**
* struct hw_perf_event - performance event hardware details:
*/
@@ -112,8 +110,6 @@ struct hw_perf_event {
struct hw_perf_event_extra extra_reg;
struct hw_perf_event_extra branch_reg;
-
- struct event_constraint *constraint;
};
struct { /* software */
struct hrtimer hrtimer;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1a3bf48..eddf1ed 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3442,7 +3442,6 @@ static void free_event_rcu(struct rcu_head *head)
if (event->ns)
put_pid_ns(event->ns);
perf_event_free_filter(event);
- perf_event_free_bpf_prog(event);
kfree(event);
}
@@ -3573,6 +3572,8 @@ static void __free_event(struct perf_event *event)
put_callchain_buffers();
}
+ perf_event_free_bpf_prog(event);
+
if (event->destroy)
event->destroy(event);
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 232f00f..725c416 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -493,6 +493,20 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
rb->aux_pages[rb->aux_nr_pages] = page_address(page++);
}
+ /*
+ * In overwrite mode, PMUs that don't support SG may not handle more
+ * than one contiguous allocation, since they rely on PMI to do double
+ * buffering. In this case, the entire buffer has to be one contiguous
+ * chunk.
+ */
+ if ((event->pmu->capabilities & PERF_PMU_CAP_AUX_NO_SG) &&
+ overwrite) {
+ struct page *page = virt_to_page(rb->aux_pages[0]);
+
+ if (page_private(page) != max_order)
+ goto out;
+ }
+
rb->aux_priv = event->pmu->setup_aux(event->cpu, rb->aux_pages, nr_pages,
overwrite);
if (!rb->aux_priv)
generated by cgit v0.10.2 at 2024-11-15 05:19:07 (GMT)