From: Peter Zijlstra <peterz@infradead.org>
To: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: acme@kernel.org, alexander.shishkin@linux.intel.com,
jolsa@redhat.com, namhyung@kernel.org, songliubraving@fb.com,
eranian@google.com, alexey.budankov@linux.intel.com,
ak@linux.intel.com, mark.rutland@arm.com, megha.dey@intel.com,
frederic@kernel.org, maddy@linux.ibm.com, irogers@google.com,
kim.phillips@amd.com, linux-kernel@vger.kernel.org,
santosh.shukla@amd.com
Subject: Re: [RFC v2] perf: Rewrite core context handling
Date: Mon, 13 Jun 2022 16:35:11 +0200 [thread overview]
Message-ID: <YqdLH+ZU/sf4n0pa@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20220113134743.1292-1-ravi.bangoria@amd.com>
Right, so sorry for being incredibly tardy on this. Find below the
patch fwd ported to something recent.
I'll reply to this with fixes and comments.
---
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -132,7 +132,7 @@ static unsigned long ebb_switch_in(bool
static inline void power_pmu_bhrb_enable(struct perf_event *event) {}
static inline void power_pmu_bhrb_disable(struct perf_event *event) {}
-static void power_pmu_sched_task(struct perf_event_context *ctx, bool sched_in) {}
+static void power_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in) {}
static inline void power_pmu_bhrb_read(struct perf_event *event, struct cpu_hw_events *cpuhw) {}
static void pmao_restore_workaround(bool ebb) { }
#endif /* CONFIG_PPC32 */
@@ -451,7 +451,7 @@ static void power_pmu_bhrb_disable(struc
/* Called from ctxsw to prevent one process's branch entries to
* mingle with the other process's entries during context switch.
*/
-static void power_pmu_sched_task(struct perf_event_context *ctx, bool sched_in)
+static void power_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in)
{
if (!ppmu->bhrb_nr)
return;
--- a/arch/x86/events/amd/brs.c
+++ b/arch/x86/events/amd/brs.c
@@ -317,7 +317,7 @@ static void amd_brs_poison_buffer(void)
* On ctxswin, sched_in = true, called after the PMU has started
* On ctxswout, sched_in = false, called before the PMU is stopped
*/
-void amd_pmu_brs_sched_task(struct perf_event_context *ctx, bool sched_in)
+void amd_pmu_brs_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -1248,11 +1248,11 @@ static ssize_t amd_event_sysfs_show(char
return x86_event_sysfs_show(page, config, event);
}
-static void amd_pmu_sched_task(struct perf_event_context *ctx,
+static void amd_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx,
bool sched_in)
{
if (sched_in && x86_pmu.lbr_nr)
- amd_pmu_brs_sched_task(ctx, sched_in);
+ amd_pmu_brs_sched_task(pmu_ctx, sched_in);
}
static u64 amd_pmu_limit_period(struct perf_event *event, u64 left)
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2067,13 +2067,14 @@ void x86_pmu_show_pmu_cap(int num_counte
*/
void x86_pmu_update_cpu_context(struct pmu *pmu, int cpu)
{
- struct perf_cpu_context *cpuctx;
+ /* XXX: Don't need this quirk anymore */
+ /*struct perf_cpu_context *cpuctx;
if (!pmu->pmu_cpu_context)
return;
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
- cpuctx->ctx.pmu = pmu;
+ cpuctx->ctx.pmu = pmu;*/
}
static int __init init_hw_perf_events(void)
@@ -2644,15 +2645,15 @@ static const struct attribute_group *x86
NULL,
};
-static void x86_pmu_sched_task(struct perf_event_context *ctx, bool sched_in)
+static void x86_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in)
{
- static_call_cond(x86_pmu_sched_task)(ctx, sched_in);
+ static_call_cond(x86_pmu_sched_task)(pmu_ctx, sched_in);
}
-static void x86_pmu_swap_task_ctx(struct perf_event_context *prev,
- struct perf_event_context *next)
+static void x86_pmu_swap_task_ctx(struct perf_event_pmu_context *prev_epc,
+ struct perf_event_pmu_context *next_epc)
{
- static_call_cond(x86_pmu_swap_task_ctx)(prev, next);
+ static_call_cond(x86_pmu_swap_task_ctx)(prev_epc, next_epc);
}
void perf_check_microcode(void)
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4545,17 +4545,17 @@ static void intel_pmu_cpu_dead(int cpu)
cpumask_clear_cpu(cpu, &hybrid_pmu(cpuc->pmu)->supported_cpus);
}
-static void intel_pmu_sched_task(struct perf_event_context *ctx,
+static void intel_pmu_sched_task(struct perf_event_pmu_context *pmu_ctx,
bool sched_in)
{
- intel_pmu_pebs_sched_task(ctx, sched_in);
- intel_pmu_lbr_sched_task(ctx, sched_in);
+ intel_pmu_pebs_sched_task(pmu_ctx, sched_in);
+ intel_pmu_lbr_sched_task(pmu_ctx, sched_in);
}
-static void intel_pmu_swap_task_ctx(struct perf_event_context *prev,
- struct perf_event_context *next)
+static void intel_pmu_swap_task_ctx(struct perf_event_pmu_context *prev_epc,
+ struct perf_event_pmu_context *next_epc)
{
- intel_pmu_lbr_swap_task_ctx(prev, next);
+ intel_pmu_lbr_swap_task_ctx(prev_epc, next_epc);
}
static int intel_pmu_check_period(struct perf_event *event, u64 value)
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1005,7 +1005,7 @@ static inline bool pebs_needs_sched_cb(s
return cpuc->n_pebs && (cpuc->n_pebs == cpuc->n_large_pebs);
}
-void intel_pmu_pebs_sched_task(struct perf_event_context *ctx, bool sched_in)
+void intel_pmu_pebs_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
@@ -1113,7 +1113,7 @@ static void
pebs_update_state(bool needed_cb, struct cpu_hw_events *cpuc,
struct perf_event *event, bool add)
{
- struct pmu *pmu = event->ctx->pmu;
+ struct pmu *pmu = event->pmu;
/*
* Make sure we get updated with the first PEBS
* event. It will trigger also during removal, but
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -575,21 +575,21 @@ static void __intel_pmu_lbr_save(void *c
cpuc->last_log_id = ++task_context_opt(ctx)->log_id;
}
-void intel_pmu_lbr_swap_task_ctx(struct perf_event_context *prev,
- struct perf_event_context *next)
+void intel_pmu_lbr_swap_task_ctx(struct perf_event_pmu_context *prev_epc,
+ struct perf_event_pmu_context *next_epc)
{
void *prev_ctx_data, *next_ctx_data;
- swap(prev->task_ctx_data, next->task_ctx_data);
+ swap(prev_epc->task_ctx_data, next_epc->task_ctx_data);
/*
- * Architecture specific synchronization makes sense in
- * case both prev->task_ctx_data and next->task_ctx_data
+ * Architecture specific synchronization makes sense in case
+ * both prev_epc->task_ctx_data and next_epc->task_ctx_data
* pointers are allocated.
*/
- prev_ctx_data = next->task_ctx_data;
- next_ctx_data = prev->task_ctx_data;
+ prev_ctx_data = next_epc->task_ctx_data;
+ next_ctx_data = prev_epc->task_ctx_data;
if (!prev_ctx_data || !next_ctx_data)
return;
@@ -598,7 +598,7 @@ void intel_pmu_lbr_swap_task_ctx(struct
task_context_opt(next_ctx_data)->lbr_callstack_users);
}
-void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in)
+void intel_pmu_lbr_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
void *task_ctx;
@@ -611,7 +611,7 @@ void intel_pmu_lbr_sched_task(struct per
* the task was scheduled out, restore the stack. Otherwise flush
* the LBR stack.
*/
- task_ctx = ctx ? ctx->task_ctx_data : NULL;
+ task_ctx = pmu_ctx ? pmu_ctx->task_ctx_data : NULL;
if (task_ctx) {
if (sched_in)
__intel_pmu_lbr_restore(task_ctx);
@@ -647,8 +647,8 @@ void intel_pmu_lbr_add(struct perf_event
cpuc->br_sel = event->hw.branch_reg.reg;
- if (branch_user_callstack(cpuc->br_sel) && event->ctx->task_ctx_data)
- task_context_opt(event->ctx->task_ctx_data)->lbr_callstack_users++;
+ if (branch_user_callstack(cpuc->br_sel) && event->pmu_ctx->task_ctx_data)
+ task_context_opt(event->pmu_ctx->task_ctx_data)->lbr_callstack_users++;
/*
* Request pmu::sched_task() callback, which will fire inside the
@@ -671,7 +671,7 @@ void intel_pmu_lbr_add(struct perf_event
*/
if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip > 0)
cpuc->lbr_pebs_users++;
- perf_sched_cb_inc(event->ctx->pmu);
+ perf_sched_cb_inc(event->pmu);
if (!cpuc->lbr_users++ && !event->total_time_running)
intel_pmu_lbr_reset();
}
@@ -724,8 +724,8 @@ void intel_pmu_lbr_del(struct perf_event
return;
if (branch_user_callstack(cpuc->br_sel) &&
- event->ctx->task_ctx_data)
- task_context_opt(event->ctx->task_ctx_data)->lbr_callstack_users--;
+ event->pmu_ctx->task_ctx_data)
+ task_context_opt(event->pmu_ctx->task_ctx_data)->lbr_callstack_users--;
if (event->hw.flags & PERF_X86_EVENT_LBR_SELECT)
cpuc->lbr_select = 0;
@@ -735,7 +735,7 @@ void intel_pmu_lbr_del(struct perf_event
cpuc->lbr_users--;
WARN_ON_ONCE(cpuc->lbr_users < 0);
WARN_ON_ONCE(cpuc->lbr_pebs_users < 0);
- perf_sched_cb_dec(event->ctx->pmu);
+ perf_sched_cb_dec(event->pmu);
}
static inline bool vlbr_exclude_host(void)
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -798,7 +798,7 @@ struct x86_pmu {
void (*cpu_dead)(int cpu);
void (*check_microcode)(void);
- void (*sched_task)(struct perf_event_context *ctx,
+ void (*sched_task)(struct perf_event_pmu_context *pmu_ctx,
bool sched_in);
/*
@@ -880,12 +880,12 @@ struct x86_pmu {
int (*set_topdown_event_period)(struct perf_event *event);
/*
- * perf task context (i.e. struct perf_event_context::task_ctx_data)
+ * perf task context (i.e. struct perf_event_pmu_context::task_ctx_data)
* switch helper to bridge calls from perf/core to perf/x86.
* See struct pmu::swap_task_ctx() usage for examples;
*/
- void (*swap_task_ctx)(struct perf_event_context *prev,
- struct perf_event_context *next);
+ void (*swap_task_ctx)(struct perf_event_pmu_context *prev_epc,
+ struct perf_event_pmu_context *next_epc);
/*
* AMD bits
@@ -1253,7 +1253,7 @@ static inline void amd_pmu_brs_del(struc
perf_sched_cb_dec(event->ctx->pmu);
}
-void amd_pmu_brs_sched_task(struct perf_event_context *ctx, bool sched_in);
+void amd_pmu_brs_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in);
#else
static inline int amd_brs_init(void)
{
@@ -1278,7 +1278,7 @@ static inline void amd_pmu_brs_del(struc
{
}
-static inline void amd_pmu_brs_sched_task(struct perf_event_context *ctx, bool sched_in)
+static inline void amd_pmu_brs_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in)
{
}
@@ -1436,7 +1436,7 @@ void intel_pmu_pebs_enable_all(void);
void intel_pmu_pebs_disable_all(void);
-void intel_pmu_pebs_sched_task(struct perf_event_context *ctx, bool sched_in);
+void intel_pmu_pebs_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in);
void intel_pmu_auto_reload_read(struct perf_event *event);
@@ -1444,10 +1444,10 @@ void intel_pmu_store_pebs_lbrs(struct lb
void intel_ds_init(void);
-void intel_pmu_lbr_swap_task_ctx(struct perf_event_context *prev,
- struct perf_event_context *next);
+void intel_pmu_lbr_swap_task_ctx(struct perf_event_pmu_context *prev_epc,
+ struct perf_event_pmu_context *next_epc);
-void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in);
+void intel_pmu_lbr_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in);
u64 lbr_from_signext_quirk_wr(u64 val);
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -262,6 +262,7 @@ struct hw_perf_event {
};
struct perf_event;
+struct perf_event_pmu_context;
/*
* Common implementation detail of pmu::{start,commit,cancel}_txn
@@ -304,7 +305,7 @@ struct pmu {
int capabilities;
int __percpu *pmu_disable_count;
- struct perf_cpu_context __percpu *pmu_cpu_context;
+ struct perf_cpu_pmu_context __percpu *cpu_pmu_context;
atomic_t exclusive_cnt; /* < 0: cpu; > 0: tsk */
int task_ctx_nr;
int hrtimer_interval_ms;
@@ -439,7 +440,7 @@ struct pmu {
/*
* context-switches callback
*/
- void (*sched_task) (struct perf_event_context *ctx,
+ void (*sched_task) (struct perf_event_pmu_context *pmu_ctx,
bool sched_in);
/*
@@ -453,8 +454,8 @@ struct pmu {
* implementation and Perf core context switch handling callbacks for usage
* examples.
*/
- void (*swap_task_ctx) (struct perf_event_context *prev,
- struct perf_event_context *next);
+ void (*swap_task_ctx) (struct perf_event_pmu_context *prev_epc,
+ struct perf_event_pmu_context *next_epc);
/* optional */
/*
@@ -675,6 +676,11 @@ struct perf_event {
int group_caps;
struct perf_event *group_leader;
+ /*
+ * event->pmu will always point to pmu in which this event belongs.
+ * Unlike event->pmu_ctx->pmu which points to other pmu when group of
+ * different events are created.
+ */
struct pmu *pmu;
void *pmu_private;
@@ -700,6 +706,12 @@ struct perf_event {
struct hw_perf_event hw;
struct perf_event_context *ctx;
+ /*
+ * event->pmu_ctx points to perf_event_pmu_context in which the event
+ * is added. This pmu_ctx can be of other pmu for sw event when such
+ * sw event is added to a non-sw event group.
+ */
+ struct perf_event_pmu_context *pmu_ctx;
atomic_long_t refcount;
/*
@@ -787,19 +799,60 @@ struct perf_event {
#endif /* CONFIG_PERF_EVENTS */
};
+/*
+ * ,------------------------[1:n]---------------------.
+ * V V
+ * perf_event_context <-[1:n]-> perf_event_pmu_context <--- perf_event
+ * ^ ^ | |
+ * `--------[1:n]---------' `-[n:1]-> pmu <-[1:n]-'
+ *
+ *
+ * XXX destroy epc when empty
+ * refcount, !rcu
+ *
+ * XXX epc locking
+ *
+ * event->pmu_ctx ctx->mutex && inactive
+ * ctx->pmu_ctx_list ctx->mutex && ctx->lock
+ *
+ */
+struct perf_event_pmu_context {
+ struct pmu *pmu;
+ struct perf_event_context *ctx;
+
+ struct list_head pmu_ctx_entry;
+
+ struct list_head pinned_active;
+ struct list_head flexible_active;
+
+ /* Used to avoid freeing per-cpu perf_event_pmu_context */
+ unsigned int embedded : 1;
+
+ unsigned int nr_events;
+ unsigned int nr_active;
+
+ atomic_t refcount; /* event <-> epc */
+
+ void *task_ctx_data; /* pmu specific data */
+ /*
+ * Set when nr_events != nr_active, except tolerant to events not
+ * necessary to be active due to scheduling constraints, such as cgroups.
+ */
+ int rotate_necessary;
+};
struct perf_event_groups {
struct rb_root tree;
u64 index;
};
+
/**
* struct perf_event_context - event context structure
*
* Used as a container for task events and CPU events as well:
*/
struct perf_event_context {
- struct pmu *pmu;
/*
* Protect the states of the events in the list,
* nr_active, and the list:
@@ -812,26 +865,21 @@ struct perf_event_context {
*/
struct mutex mutex;
- struct list_head active_ctx_list;
+ struct list_head pmu_ctx_list;
struct perf_event_groups pinned_groups;
struct perf_event_groups flexible_groups;
struct list_head event_list;
- struct list_head pinned_active;
- struct list_head flexible_active;
-
int nr_events;
int nr_active;
int nr_user;
int is_active;
+
+ int nr_task_data;
int nr_stat;
int nr_freq;
int rotate_disable;
- /*
- * Set when nr_events != nr_active, except tolerant to events not
- * necessary to be active due to scheduling constraints, such as cgroups.
- */
- int rotate_necessary;
+
refcount_t refcount;
struct task_struct *task;
@@ -853,7 +901,6 @@ struct perf_event_context {
#ifdef CONFIG_CGROUP_PERF
int nr_cgroups; /* cgroup evts */
#endif
- void *task_ctx_data; /* pmu specific data */
struct rcu_head rcu_head;
};
@@ -863,12 +910,13 @@ struct perf_event_context {
*/
#define PERF_NR_CONTEXTS 4
-/**
- * struct perf_cpu_context - per cpu event context structure
- */
-struct perf_cpu_context {
- struct perf_event_context ctx;
- struct perf_event_context *task_ctx;
+struct perf_cpu_pmu_context {
+ struct perf_event_pmu_context epc;
+ struct perf_event_pmu_context *task_epc;
+
+ struct list_head sched_cb_entry;
+ int sched_cb_usage;
+
int active_oncpu;
int exclusive;
@@ -876,16 +924,21 @@ struct perf_cpu_context {
struct hrtimer hrtimer;
ktime_t hrtimer_interval;
unsigned int hrtimer_active;
+};
+
+/**
+ * struct perf_event_cpu_context - per cpu event context structure
+ */
+struct perf_cpu_context {
+ struct perf_event_context ctx;
+ struct perf_event_context *task_ctx;
+ int online;
#ifdef CONFIG_CGROUP_PERF
struct perf_cgroup *cgrp;
struct list_head cgrp_cpuctx_entry;
#endif
- struct list_head sched_cb_entry;
- int sched_cb_usage;
-
- int online;
/*
* Per-CPU storage for iterators used in visit_groups_merge. The default
* storage is of size 2 to hold the CPU and any CPU event iterators.
@@ -1151,7 +1204,7 @@ static inline int is_software_event(stru
*/
static inline int in_software_context(struct perf_event *event)
{
- return event->ctx->pmu->task_ctx_nr == perf_sw_context;
+ return event->pmu_ctx->pmu->task_ctx_nr == perf_sw_context;
}
static inline int is_exclusive_pmu(struct pmu *pmu)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1226,7 +1226,7 @@ struct task_struct {
unsigned int futex_state;
#endif
#ifdef CONFIG_PERF_EVENTS
- struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
+ struct perf_event_context *perf_event_ctxp;
struct mutex perf_event_mutex;
struct list_head perf_event_list;
#endif
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -154,12 +154,6 @@ static int cpu_function_call(int cpu, re
return data.ret;
}
-static inline struct perf_cpu_context *
-__get_cpu_context(struct perf_event_context *ctx)
-{
- return this_cpu_ptr(ctx->pmu->pmu_cpu_context);
-}
-
static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
struct perf_event_context *ctx)
{
@@ -183,6 +177,8 @@ static bool is_kernel_event(struct perf_
return READ_ONCE(event->owner) == TASK_TOMBSTONE;
}
+static DEFINE_PER_CPU(struct perf_cpu_context, cpu_context);
+
/*
* On task ctx scheduling...
*
@@ -216,7 +212,7 @@ static int event_function(void *info)
struct event_function_struct *efs = info;
struct perf_event *event = efs->event;
struct perf_event_context *ctx = event->ctx;
- struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
struct perf_event_context *task_ctx = cpuctx->task_ctx;
int ret = 0;
@@ -313,7 +309,7 @@ static void event_function_call(struct p
static void event_function_local(struct perf_event *event, event_f func, void *data)
{
struct perf_event_context *ctx = event->ctx;
- struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
struct task_struct *task = READ_ONCE(ctx->task);
struct perf_event_context *task_ctx = NULL;
@@ -387,7 +383,6 @@ static DEFINE_MUTEX(perf_sched_mutex);
static atomic_t perf_sched_count;
static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
-static DEFINE_PER_CPU(int, perf_sched_cb_usages);
static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events);
static atomic_t nr_mmap_events __read_mostly;
@@ -447,7 +442,7 @@ static void update_perf_cpu_limits(void)
WRITE_ONCE(perf_sample_allowed_ns, tmp);
}
-static bool perf_rotate_context(struct perf_cpu_context *cpuctx);
+static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc);
int perf_proc_update_handler(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
@@ -570,12 +565,6 @@ void perf_sample_event_took(u64 sample_l
static atomic64_t perf_event_id;
-static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
- enum event_type_t event_type);
-
-static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
- enum event_type_t event_type);
-
static void update_context_time(struct perf_event_context *ctx);
static u64 perf_event_time(struct perf_event *event);
@@ -690,13 +679,31 @@ do { \
___p; \
})
+static void perf_ctx_disable(struct perf_event_context *ctx)
+{
+ struct perf_event_pmu_context *pmu_ctx;
+
+ list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry)
+ perf_pmu_disable(pmu_ctx->pmu);
+}
+
+static void perf_ctx_enable(struct perf_event_context *ctx)
+{
+ struct perf_event_pmu_context *pmu_ctx;
+
+ list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry)
+ perf_pmu_enable(pmu_ctx->pmu);
+}
+
+static void ctx_sched_out(struct perf_event_context *ctx, enum event_type_t event_type);
+static void ctx_sched_in(struct perf_event_context *ctx, enum event_type_t event_type);
+
#ifdef CONFIG_CGROUP_PERF
static inline bool
perf_cgroup_match(struct perf_event *event)
{
- struct perf_event_context *ctx = event->ctx;
- struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
/* @event doesn't care about cgroup */
if (!event->cgrp)
@@ -822,6 +829,7 @@ perf_cgroup_set_timestamp(struct perf_cp
}
}
+/* XXX: No need of list now. Convert it to per-cpu variable */
static DEFINE_PER_CPU(struct list_head, cgrp_cpuctx_list);
/*
@@ -849,9 +857,9 @@ static void perf_cgroup_switch(struct ta
continue;
perf_ctx_lock(cpuctx, cpuctx->task_ctx);
- perf_pmu_disable(cpuctx->ctx.pmu);
+ perf_ctx_disable(&cpuctx->ctx);
- cpu_ctx_sched_out(cpuctx, EVENT_ALL);
+ ctx_sched_out(&cpuctx->ctx, EVENT_ALL);
/*
* must not be done before ctxswout due
* to update_cgrp_time_from_cpuctx() in
@@ -863,9 +871,9 @@ static void perf_cgroup_switch(struct ta
* perf_cgroup_set_timestamp() in ctx_sched_in()
* to not have to pass task around
*/
- cpu_ctx_sched_in(cpuctx, EVENT_ALL);
+ ctx_sched_in(&cpuctx->ctx, EVENT_ALL);
- perf_pmu_enable(cpuctx->ctx.pmu);
+ perf_ctx_enable(&cpuctx->ctx);
perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
}
@@ -887,7 +895,7 @@ static int perf_cgroup_ensure_storage(st
heap_size++;
for_each_possible_cpu(cpu) {
- cpuctx = per_cpu_ptr(event->pmu->pmu_cpu_context, cpu);
+ cpuctx = this_cpu_ptr(&cpu_context);
if (heap_size <= cpuctx->heap_size)
continue;
@@ -1068,34 +1076,30 @@ static void perf_cgroup_switch(struct ta
*/
static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr)
{
- struct perf_cpu_context *cpuctx;
+ struct perf_cpu_pmu_context *cpc;
bool rotations;
lockdep_assert_irqs_disabled();
- cpuctx = container_of(hr, struct perf_cpu_context, hrtimer);
- rotations = perf_rotate_context(cpuctx);
+ cpc = container_of(hr, struct perf_cpu_pmu_context, hrtimer);
+ rotations = perf_rotate_context(cpc);
- raw_spin_lock(&cpuctx->hrtimer_lock);
+ raw_spin_lock(&cpc->hrtimer_lock);
if (rotations)
- hrtimer_forward_now(hr, cpuctx->hrtimer_interval);
+ hrtimer_forward_now(hr, cpc->hrtimer_interval);
else
- cpuctx->hrtimer_active = 0;
- raw_spin_unlock(&cpuctx->hrtimer_lock);
+ cpc->hrtimer_active = 0;
+ raw_spin_unlock(&cpc->hrtimer_lock);
return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART;
}
-static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu)
+static void __perf_mux_hrtimer_init(struct perf_cpu_pmu_context *cpc, int cpu)
{
- struct hrtimer *timer = &cpuctx->hrtimer;
- struct pmu *pmu = cpuctx->ctx.pmu;
+ struct hrtimer *timer = &cpc->hrtimer;
+ struct pmu *pmu = cpc->epc.pmu;
u64 interval;
- /* no multiplexing needed for SW PMU */
- if (pmu->task_ctx_nr == perf_sw_context)
- return;
-
/*
* check default is sane, if not set then force to
* default interval (1/tick)
@@ -1104,30 +1108,25 @@ static void __perf_mux_hrtimer_init(stru
if (interval < 1)
interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;
- cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
+ cpc->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
- raw_spin_lock_init(&cpuctx->hrtimer_lock);
+ raw_spin_lock_init(&cpc->hrtimer_lock);
hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED_HARD);
timer->function = perf_mux_hrtimer_handler;
}
-static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx)
+static int perf_mux_hrtimer_restart(struct perf_cpu_pmu_context *cpc)
{
- struct hrtimer *timer = &cpuctx->hrtimer;
- struct pmu *pmu = cpuctx->ctx.pmu;
+ struct hrtimer *timer = &cpc->hrtimer;
unsigned long flags;
- /* not for SW PMU */
- if (pmu->task_ctx_nr == perf_sw_context)
- return 0;
-
- raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags);
- if (!cpuctx->hrtimer_active) {
- cpuctx->hrtimer_active = 1;
- hrtimer_forward_now(timer, cpuctx->hrtimer_interval);
+ raw_spin_lock_irqsave(&cpc->hrtimer_lock, flags);
+ if (!cpc->hrtimer_active) {
+ cpc->hrtimer_active = 1;
+ hrtimer_forward_now(timer, cpc->hrtimer_interval);
hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED_HARD);
}
- raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags);
+ raw_spin_unlock_irqrestore(&cpc->hrtimer_lock, flags);
return 0;
}
@@ -1146,32 +1145,9 @@ void perf_pmu_enable(struct pmu *pmu)
pmu->pmu_enable(pmu);
}
-static DEFINE_PER_CPU(struct list_head, active_ctx_list);
-
-/*
- * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
- * perf_event_task_tick() are fully serialized because they're strictly cpu
- * affine and perf_event_ctx{activate,deactivate} are called with IRQs
- * disabled, while perf_event_task_tick is called from IRQ context.
- */
-static void perf_event_ctx_activate(struct perf_event_context *ctx)
-{
- struct list_head *head = this_cpu_ptr(&active_ctx_list);
-
- lockdep_assert_irqs_disabled();
-
- WARN_ON(!list_empty(&ctx->active_ctx_list));
-
- list_add(&ctx->active_ctx_list, head);
-}
-
-static void perf_event_ctx_deactivate(struct perf_event_context *ctx)
+static void perf_assert_pmu_disabled(struct pmu *pmu)
{
- lockdep_assert_irqs_disabled();
-
- WARN_ON(list_empty(&ctx->active_ctx_list));
-
- list_del_init(&ctx->active_ctx_list);
+ WARN_ON_ONCE(*this_cpu_ptr(pmu->pmu_disable_count) == 0);
}
static void get_ctx(struct perf_event_context *ctx)
@@ -1198,7 +1174,6 @@ static void free_ctx(struct rcu_head *he
struct perf_event_context *ctx;
ctx = container_of(head, struct perf_event_context, rcu_head);
- free_task_ctx_data(ctx->pmu, ctx->task_ctx_data);
kfree(ctx);
}
@@ -1383,7 +1358,7 @@ static u64 primary_event_id(struct perf_
* the context could get moved to another task.
*/
static struct perf_event_context *
-perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
+perf_lock_task_context(struct task_struct *task, unsigned long *flags)
{
struct perf_event_context *ctx;
@@ -1399,7 +1374,7 @@ perf_lock_task_context(struct task_struc
*/
local_irq_save(*flags);
rcu_read_lock();
- ctx = rcu_dereference(task->perf_event_ctxp[ctxn]);
+ ctx = rcu_dereference(task->perf_event_ctxp);
if (ctx) {
/*
* If this context is a clone of another, it might
@@ -1412,7 +1387,7 @@ perf_lock_task_context(struct task_struc
* can't get swapped on us any more.
*/
raw_spin_lock(&ctx->lock);
- if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) {
+ if (ctx != rcu_dereference(task->perf_event_ctxp)) {
raw_spin_unlock(&ctx->lock);
rcu_read_unlock();
local_irq_restore(*flags);
@@ -1439,12 +1414,12 @@ perf_lock_task_context(struct task_struc
* reference count so that the context can't get freed.
*/
static struct perf_event_context *
-perf_pin_task_context(struct task_struct *task, int ctxn)
+perf_pin_task_context(struct task_struct *task)
{
struct perf_event_context *ctx;
unsigned long flags;
- ctx = perf_lock_task_context(task, ctxn, &flags);
+ ctx = perf_lock_task_context(task, &flags);
if (ctx) {
++ctx->pin_count;
raw_spin_unlock_irqrestore(&ctx->lock, flags);
@@ -1590,14 +1565,22 @@ static inline struct cgroup *event_cgrou
* which provides ordering when rotating groups for the same CPU.
*/
static __always_inline int
-perf_event_groups_cmp(const int left_cpu, const struct cgroup *left_cgroup,
- const u64 left_group_index, const struct perf_event *right)
+perf_event_groups_cmp(const int left_cpu, const struct pmu *left_pmu,
+ const struct cgroup *left_cgroup, const u64 left_group_index,
+ const struct perf_event *right)
{
if (left_cpu < right->cpu)
return -1;
if (left_cpu > right->cpu)
return 1;
+ if (left_pmu) {
+ if (left_pmu < right->pmu_ctx->pmu)
+ return -1;
+ if (left_pmu > right->pmu_ctx->pmu)
+ return 1;
+ }
+
#ifdef CONFIG_CGROUP_PERF
{
const struct cgroup *right_cgroup = event_cgroup(right);
@@ -1640,12 +1623,13 @@ perf_event_groups_cmp(const int left_cpu
static inline bool __group_less(struct rb_node *a, const struct rb_node *b)
{
struct perf_event *e = __node_2_pe(a);
- return perf_event_groups_cmp(e->cpu, event_cgroup(e), e->group_index,
- __node_2_pe(b)) < 0;
+ return perf_event_groups_cmp(e->cpu, e->pmu_ctx->pmu, event_cgroup(e),
+ e->group_index, __node_2_pe(b)) < 0;
}
struct __group_key {
int cpu;
+ struct pmu *pmu;
struct cgroup *cgroup;
};
@@ -1654,14 +1638,25 @@ static inline int __group_cmp(const void
const struct __group_key *a = key;
const struct perf_event *b = __node_2_pe(node);
- /* partial/subtree match: @cpu, @cgroup; ignore: @group_index */
- return perf_event_groups_cmp(a->cpu, a->cgroup, b->group_index, b);
+ /* partial/subtree match: @cpu, @pmu, @cgroup; ignore: @group_index */
+ return perf_event_groups_cmp(a->cpu, a->pmu, a->cgroup, b->group_index, b);
+}
+
+static inline int
+__group_cmp_ignore_cgroup(const void *key, const struct rb_node *node)
+{
+ const struct __group_key *a = key;
+ const struct perf_event *b = __node_2_pe(node);
+
+ /* partial/subtree match: @cpu, @pmu, ignore: @cgroup, @group_index */
+ return perf_event_groups_cmp(a->cpu, a->pmu, event_cgroup(b),
+ b->group_index, b);
}
/*
- * Insert @event into @groups' tree; using {@event->cpu, ++@groups->index} for
- * key (see perf_event_groups_less). This places it last inside the CPU
- * subtree.
+ * Insert @event into @groups' tree; using
+ * {@event->cpu, @event->pmu_ctx->pmu, event_cgroup(@event), ++@groups->index}
+ * as key. This places it last inside the {cpu,pmu,cgroup} subtree.
*/
static void
perf_event_groups_insert(struct perf_event_groups *groups,
@@ -1711,14 +1706,15 @@ del_event_from_groups(struct perf_event
}
/*
- * Get the leftmost event in the cpu/cgroup subtree.
+ * Get the leftmost event in the {cpu,pmu,cgroup} subtree.
*/
static struct perf_event *
perf_event_groups_first(struct perf_event_groups *groups, int cpu,
- struct cgroup *cgrp)
+ struct pmu *pmu, struct cgroup *cgrp)
{
struct __group_key key = {
.cpu = cpu,
+ .pmu = pmu,
.cgroup = cgrp,
};
struct rb_node *node;
@@ -1730,14 +1726,12 @@ perf_event_groups_first(struct perf_even
return NULL;
}
-/*
- * Like rb_entry_next_safe() for the @cpu subtree.
- */
static struct perf_event *
-perf_event_groups_next(struct perf_event *event)
+perf_event_groups_next(struct perf_event *event, struct pmu *pmu)
{
struct __group_key key = {
.cpu = event->cpu,
+ .pmu = pmu,
.cgroup = event_cgroup(event),
};
struct rb_node *next;
@@ -1793,6 +1787,7 @@ list_add_event(struct perf_event *event,
perf_cgroup_event_enable(event, ctx);
ctx->generation++;
+ event->pmu_ctx->nr_events++;
}
/*
@@ -2000,6 +1995,7 @@ list_del_event(struct perf_event *event,
}
ctx->generation++;
+ event->pmu_ctx->nr_events--;
}
static int
@@ -2016,13 +2012,11 @@ perf_aux_output_match(struct perf_event
static void put_event(struct perf_event *event);
static void event_sched_out(struct perf_event *event,
- struct perf_cpu_context *cpuctx,
struct perf_event_context *ctx);
static void perf_put_aux_event(struct perf_event *event)
{
struct perf_event_context *ctx = event->ctx;
- struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
struct perf_event *iter;
/*
@@ -2051,7 +2045,7 @@ static void perf_put_aux_event(struct pe
* state so that we don't try to schedule it again. Note
* that perf_event_enable() will clear the ERROR status.
*/
- event_sched_out(iter, cpuctx, ctx);
+ event_sched_out(iter, ctx);
perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
}
}
@@ -2102,8 +2096,8 @@ static int perf_get_aux_event(struct per
static inline struct list_head *get_event_list(struct perf_event *event)
{
- struct perf_event_context *ctx = event->ctx;
- return event->attr.pinned ? &ctx->pinned_active : &ctx->flexible_active;
+ return event->attr.pinned ? &event->pmu_ctx->pinned_active :
+ &event->pmu_ctx->flexible_active;
}
/*
@@ -2114,10 +2108,7 @@ static inline struct list_head *get_even
*/
static inline void perf_remove_sibling_event(struct perf_event *event)
{
- struct perf_event_context *ctx = event->ctx;
- struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
-
- event_sched_out(event, cpuctx, ctx);
+ event_sched_out(event, event->ctx);
perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
}
@@ -2241,12 +2232,14 @@ event_filter_match(struct perf_event *ev
}
static void
-event_sched_out(struct perf_event *event,
- struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx)
+event_sched_out(struct perf_event *event, struct perf_event_context *ctx)
{
+ struct perf_event_pmu_context *epc = event->pmu_ctx;
+ struct perf_cpu_pmu_context *cpc = this_cpu_ptr(epc->pmu->cpu_pmu_context);
enum perf_event_state state = PERF_EVENT_STATE_INACTIVE;
+ // XXX cpc serialization, probably per-cpu IRQ disabled
+
WARN_ON_ONCE(event->ctx != ctx);
lockdep_assert_held(&ctx->lock);
@@ -2273,38 +2266,34 @@ event_sched_out(struct perf_event *event
perf_event_set_state(event, state);
if (!is_software_event(event))
- cpuctx->active_oncpu--;
- if (!--ctx->nr_active)
- perf_event_ctx_deactivate(ctx);
+ cpc->active_oncpu--;
+ ctx->nr_active--;
+ event->pmu_ctx->nr_active--;
if (event->attr.freq && event->attr.sample_freq)
ctx->nr_freq--;
- if (event->attr.exclusive || !cpuctx->active_oncpu)
- cpuctx->exclusive = 0;
+ if (event->attr.exclusive || !cpc->active_oncpu)
+ cpc->exclusive = 0;
perf_pmu_enable(event->pmu);
}
static void
-group_sched_out(struct perf_event *group_event,
- struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx)
+group_sched_out(struct perf_event *group_event, struct perf_event_context *ctx)
{
struct perf_event *event;
if (group_event->state != PERF_EVENT_STATE_ACTIVE)
return;
- perf_pmu_disable(ctx->pmu);
+ perf_assert_pmu_disabled(group_event->pmu_ctx->pmu);
- event_sched_out(group_event, cpuctx, ctx);
+ event_sched_out(group_event, ctx);
/*
* Schedule out siblings (if any):
*/
for_each_sibling_event(event, group_event)
- event_sched_out(event, cpuctx, ctx);
-
- perf_pmu_enable(ctx->pmu);
+ event_sched_out(event, ctx);
}
#define DETACH_GROUP 0x01UL
@@ -2329,19 +2318,21 @@ __perf_remove_from_context(struct perf_e
update_cgrp_time_from_cpuctx(cpuctx, false);
}
- event_sched_out(event, cpuctx, ctx);
+ event_sched_out(event, ctx);
if (flags & DETACH_GROUP)
perf_group_detach(event);
if (flags & DETACH_CHILD)
perf_child_detach(event);
list_del_event(event, ctx);
+ if (!event->pmu_ctx->nr_events)
+ event->pmu_ctx->rotate_necessary = 0;
+
if (!ctx->nr_events && ctx->is_active) {
if (ctx == &cpuctx->ctx)
update_cgrp_time_from_cpuctx(cpuctx, true);
ctx->is_active = 0;
- ctx->rotate_necessary = 0;
if (ctx->task) {
WARN_ON_ONCE(cpuctx->task_ctx != ctx);
cpuctx->task_ctx = NULL;
@@ -2376,7 +2367,7 @@ static void perf_remove_from_context(str
* cgrp_cpuctx_list.
*/
if (!ctx->is_active && !is_cgroup_event(event)) {
- __perf_remove_from_context(event, __get_cpu_context(ctx),
+ __perf_remove_from_context(event, this_cpu_ptr(&cpu_context),
ctx, (void *)flags);
raw_spin_unlock_irq(&ctx->lock);
return;
@@ -2402,13 +2393,17 @@ static void __perf_event_disable(struct
update_cgrp_time_from_event(event);
}
+ perf_pmu_disable(event->pmu_ctx->pmu);
+
if (event == event->group_leader)
- group_sched_out(event, cpuctx, ctx);
+ group_sched_out(event, ctx);
else
- event_sched_out(event, cpuctx, ctx);
+ event_sched_out(event, ctx);
perf_event_set_state(event, PERF_EVENT_STATE_OFF);
perf_cgroup_event_disable(event, ctx);
+
+ perf_pmu_enable(event->pmu_ctx->pmu);
}
/*
@@ -2471,10 +2466,10 @@ static void perf_log_throttle(struct per
static void perf_log_itrace_start(struct perf_event *event);
static int
-event_sched_in(struct perf_event *event,
- struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx)
+event_sched_in(struct perf_event *event, struct perf_event_context *ctx)
{
+ struct perf_event_pmu_context *epc = event->pmu_ctx;
+ struct perf_cpu_pmu_context *cpc = this_cpu_ptr(epc->pmu->cpu_pmu_context);
int ret = 0;
WARN_ON_ONCE(event->ctx != ctx);
@@ -2515,14 +2510,14 @@ event_sched_in(struct perf_event *event,
}
if (!is_software_event(event))
- cpuctx->active_oncpu++;
- if (!ctx->nr_active++)
- perf_event_ctx_activate(ctx);
+ cpc->active_oncpu++;
+ ctx->nr_active++;
+ event->pmu_ctx->nr_active++;
if (event->attr.freq && event->attr.sample_freq)
ctx->nr_freq++;
if (event->attr.exclusive)
- cpuctx->exclusive = 1;
+ cpc->exclusive = 1;
out:
perf_pmu_enable(event->pmu);
@@ -2531,26 +2526,24 @@ event_sched_in(struct perf_event *event,
}
static int
-group_sched_in(struct perf_event *group_event,
- struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx)
+group_sched_in(struct perf_event *group_event, struct perf_event_context *ctx)
{
struct perf_event *event, *partial_group = NULL;
- struct pmu *pmu = ctx->pmu;
+ struct pmu *pmu = group_event->pmu_ctx->pmu;
if (group_event->state == PERF_EVENT_STATE_OFF)
return 0;
pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
- if (event_sched_in(group_event, cpuctx, ctx))
+ if (event_sched_in(group_event, ctx))
goto error;
/*
* Schedule in siblings as one group (if any):
*/
for_each_sibling_event(event, group_event) {
- if (event_sched_in(event, cpuctx, ctx)) {
+ if (event_sched_in(event, ctx)) {
partial_group = event;
goto group_error;
}
@@ -2569,9 +2562,9 @@ group_sched_in(struct perf_event *group_
if (event == partial_group)
break;
- event_sched_out(event, cpuctx, ctx);
+ event_sched_out(event, ctx);
}
- event_sched_out(group_event, cpuctx, ctx);
+ event_sched_out(group_event, ctx);
error:
pmu->cancel_txn(pmu);
@@ -2581,10 +2574,11 @@ group_sched_in(struct perf_event *group_
/*
* Work out whether we can put this event group on the CPU now.
*/
-static int group_can_go_on(struct perf_event *event,
- struct perf_cpu_context *cpuctx,
- int can_add_hw)
+static int group_can_go_on(struct perf_event *event, int can_add_hw)
{
+ struct perf_event_pmu_context *epc = event->pmu_ctx;
+ struct perf_cpu_pmu_context *cpc = this_cpu_ptr(epc->pmu->cpu_pmu_context);
+
/*
* Groups consisting entirely of software events can always go on.
*/
@@ -2594,7 +2588,7 @@ static int group_can_go_on(struct perf_e
* If an exclusive group is already on, no other hardware
* events can go on.
*/
- if (cpuctx->exclusive)
+ if (cpc->exclusive)
return 0;
/*
* If this group is exclusive and there are already
@@ -2616,36 +2610,29 @@ static void add_event_to_ctx(struct perf
perf_group_attach(event);
}
-static void ctx_sched_out(struct perf_event_context *ctx,
- struct perf_cpu_context *cpuctx,
- enum event_type_t event_type);
-static void
-ctx_sched_in(struct perf_event_context *ctx,
- struct perf_cpu_context *cpuctx,
- enum event_type_t event_type);
-
-static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx,
- enum event_type_t event_type)
+static void task_ctx_sched_out(struct perf_event_context *ctx,
+ enum event_type_t event_type)
{
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
+
if (!cpuctx->task_ctx)
return;
if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
return;
- ctx_sched_out(ctx, cpuctx, event_type);
+ ctx_sched_out(ctx, event_type);
}
static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
struct perf_event_context *ctx)
{
- cpu_ctx_sched_in(cpuctx, EVENT_PINNED);
+ ctx_sched_in(&cpuctx->ctx, EVENT_PINNED);
if (ctx)
- ctx_sched_in(ctx, cpuctx, EVENT_PINNED);
- cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE);
+ ctx_sched_in(ctx, EVENT_PINNED);
+ ctx_sched_in(&cpuctx->ctx, EVENT_FLEXIBLE);
if (ctx)
- ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE);
+ ctx_sched_in(ctx, EVENT_FLEXIBLE);
}
/*
@@ -2667,7 +2654,6 @@ static void ctx_resched(struct perf_cpu_
struct perf_event_context *task_ctx,
enum event_type_t event_type)
{
- enum event_type_t ctx_event_type;
bool cpu_event = !!(event_type & EVENT_CPU);
/*
@@ -2677,11 +2663,13 @@ static void ctx_resched(struct perf_cpu_
if (event_type & EVENT_PINNED)
event_type |= EVENT_FLEXIBLE;
- ctx_event_type = event_type & EVENT_ALL;
+ event_type &= EVENT_ALL;
- perf_pmu_disable(cpuctx->ctx.pmu);
- if (task_ctx)
- task_ctx_sched_out(cpuctx, task_ctx, event_type);
+ perf_ctx_disable(&cpuctx->ctx);
+ if (task_ctx) {
+ perf_ctx_disable(task_ctx);
+ task_ctx_sched_out(task_ctx, event_type);
+ }
/*
* Decide which cpu ctx groups to schedule out based on the types
@@ -2691,17 +2679,20 @@ static void ctx_resched(struct perf_cpu_
* - otherwise, do nothing more.
*/
if (cpu_event)
- cpu_ctx_sched_out(cpuctx, ctx_event_type);
- else if (ctx_event_type & EVENT_PINNED)
- cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
+ ctx_sched_out(&cpuctx->ctx, event_type);
+ else if (event_type & EVENT_PINNED)
+ ctx_sched_out(&cpuctx->ctx, EVENT_FLEXIBLE);
perf_event_sched_in(cpuctx, task_ctx);
- perf_pmu_enable(cpuctx->ctx.pmu);
+
+ perf_ctx_enable(&cpuctx->ctx);
+ if (task_ctx)
+ perf_ctx_enable(task_ctx);
}
void perf_pmu_resched(struct pmu *pmu)
{
- struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
struct perf_event_context *task_ctx = cpuctx->task_ctx;
perf_ctx_lock(cpuctx, task_ctx);
@@ -2719,7 +2710,7 @@ static int __perf_install_in_context(vo
{
struct perf_event *event = info;
struct perf_event_context *ctx = event->ctx;
- struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
struct perf_event_context *task_ctx = cpuctx->task_ctx;
bool reprogram = true;
int ret = 0;
@@ -2761,7 +2752,7 @@ static int __perf_install_in_context(vo
#endif
if (reprogram) {
- ctx_sched_out(ctx, cpuctx, EVENT_TIME);
+ ctx_sched_out(ctx, EVENT_TIME);
add_event_to_ctx(event, ctx);
ctx_resched(cpuctx, task_ctx, get_event_type(event));
} else {
@@ -2909,7 +2900,7 @@ static void __perf_event_enable(struct p
return;
if (ctx->is_active)
- ctx_sched_out(ctx, cpuctx, EVENT_TIME);
+ ctx_sched_out(ctx, EVENT_TIME);
perf_event_set_state(event, PERF_EVENT_STATE_INACTIVE);
perf_cgroup_event_enable(event, ctx);
@@ -2918,7 +2909,7 @@ static void __perf_event_enable(struct p
return;
if (!event_filter_match(event)) {
- ctx_sched_in(ctx, cpuctx, EVENT_TIME);
+ ctx_sched_in(ctx, EVENT_TIME);
return;
}
@@ -2927,7 +2918,7 @@ static void __perf_event_enable(struct p
* then don't put it on unless the group is on.
*/
if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) {
- ctx_sched_in(ctx, cpuctx, EVENT_TIME);
+ ctx_sched_in(ctx, EVENT_TIME);
return;
}
@@ -3196,11 +3187,52 @@ static int perf_event_modify_attr(struct
return err;
}
-static void ctx_sched_out(struct perf_event_context *ctx,
- struct perf_cpu_context *cpuctx,
- enum event_type_t event_type)
+static void __pmu_ctx_sched_out(struct perf_event_pmu_context *pmu_ctx,
+ enum event_type_t event_type)
{
+ struct perf_event_context *ctx = pmu_ctx->ctx;
struct perf_event *event, *tmp;
+ struct pmu *pmu = pmu_ctx->pmu;
+
+ if (ctx->task && !ctx->is_active) {
+ struct perf_cpu_pmu_context *cpc;
+
+ cpc = this_cpu_ptr(pmu->cpu_pmu_context);
+ WARN_ON_ONCE(cpc->task_epc != pmu_ctx);
+ cpc->task_epc = NULL;
+ }
+
+ if (!event_type)
+ return;
+
+ perf_pmu_disable(pmu);
+ if (event_type & EVENT_PINNED) {
+ list_for_each_entry_safe(event, tmp,
+ &pmu_ctx->pinned_active,
+ active_list)
+ group_sched_out(event, ctx);
+ }
+
+ if (event_type & EVENT_FLEXIBLE) {
+ list_for_each_entry_safe(event, tmp,
+ &pmu_ctx->flexible_active,
+ active_list)
+ group_sched_out(event, ctx);
+ /*
+ * Since we cleared EVENT_FLEXIBLE, also clear
+ * rotate_necessary, is will be reset by
+ * ctx_flexible_sched_in() when needed.
+ */
+ pmu_ctx->rotate_necessary = 0;
+ }
+ perf_pmu_enable(pmu);
+}
+
+static void
+ctx_sched_out(struct perf_event_context *ctx, enum event_type_t event_type)
+{
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
+ struct perf_event_pmu_context *pmu_ctx;
int is_active = ctx->is_active;
lockdep_assert_held(&ctx->lock);
@@ -3251,24 +3283,8 @@ static void ctx_sched_out(struct perf_ev
if (!ctx->nr_active || !(is_active & EVENT_ALL))
return;
- perf_pmu_disable(ctx->pmu);
- if (is_active & EVENT_PINNED) {
- list_for_each_entry_safe(event, tmp, &ctx->pinned_active, active_list)
- group_sched_out(event, cpuctx, ctx);
- }
-
- if (is_active & EVENT_FLEXIBLE) {
- list_for_each_entry_safe(event, tmp, &ctx->flexible_active, active_list)
- group_sched_out(event, cpuctx, ctx);
-
- /*
- * Since we cleared EVENT_FLEXIBLE, also clear
- * rotate_necessary, is will be reset by
- * ctx_flexible_sched_in() when needed.
- */
- ctx->rotate_necessary = 0;
- }
- perf_pmu_enable(ctx->pmu);
+ list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry)
+ __pmu_ctx_sched_out(pmu_ctx, is_active);
}
/*
@@ -3373,26 +3389,65 @@ static void perf_event_sync_stat(struct
}
}
-static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
- struct task_struct *next)
+static void perf_event_swap_task_ctx_data(struct perf_event_context *prev_ctx,
+ struct perf_event_context *next_ctx)
+{
+ struct perf_event_pmu_context *prev_epc, *next_epc;
+
+ if (!prev_ctx->nr_task_data)
+ return;
+
+ prev_epc = list_first_entry(&prev_ctx->pmu_ctx_list,
+ struct perf_event_pmu_context,
+ pmu_ctx_entry);
+ next_epc = list_first_entry(&next_ctx->pmu_ctx_list,
+ struct perf_event_pmu_context,
+ pmu_ctx_entry);
+
+ while (&prev_epc->pmu_ctx_entry != &prev_ctx->pmu_ctx_list &&
+ &next_epc->pmu_ctx_entry != &next_ctx->pmu_ctx_list) {
+
+ WARN_ON_ONCE(prev_epc->pmu != next_epc->pmu);
+
+ /*
+ * PMU specific parts of task perf context can require
+ * additional synchronization. As an example of such
+ * synchronization see implementation details of Intel
+ * LBR call stack data profiling;
+ */
+ if (prev_epc->pmu->swap_task_ctx)
+ prev_epc->pmu->swap_task_ctx(prev_epc, next_epc);
+ else
+ swap(prev_epc->task_ctx_data, next_epc->task_ctx_data);
+ }
+}
+
+static void perf_ctx_sched_task_cb(struct perf_event_context *ctx, bool sched_in)
{
- struct perf_event_context *ctx = task->perf_event_ctxp[ctxn];
+ struct perf_event_pmu_context *pmu_ctx;
+ struct perf_cpu_pmu_context *cpc;
+
+ list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
+ cpc = this_cpu_ptr(pmu_ctx->pmu->cpu_pmu_context);
+
+ if (cpc->sched_cb_usage && pmu_ctx->pmu->sched_task)
+ pmu_ctx->pmu->sched_task(pmu_ctx, sched_in);
+ }
+}
+
+static void
+perf_event_context_sched_out(struct task_struct *task, struct task_struct *next)
+{
+ struct perf_event_context *ctx = task->perf_event_ctxp;
struct perf_event_context *next_ctx;
struct perf_event_context *parent, *next_parent;
- struct perf_cpu_context *cpuctx;
int do_switch = 1;
- struct pmu *pmu;
if (likely(!ctx))
return;
- pmu = ctx->pmu;
- cpuctx = __get_cpu_context(ctx);
- if (!cpuctx->task_ctx)
- return;
-
rcu_read_lock();
- next_ctx = next->perf_event_ctxp[ctxn];
+ next_ctx = rcu_dereference(next->perf_event_ctxp);
if (!next_ctx)
goto unlock;
@@ -3420,23 +3475,12 @@ static void perf_event_context_sched_out
WRITE_ONCE(ctx->task, next);
WRITE_ONCE(next_ctx->task, task);
- perf_pmu_disable(pmu);
+ perf_ctx_disable(ctx);
- if (cpuctx->sched_cb_usage && pmu->sched_task)
- pmu->sched_task(ctx, false);
+ perf_ctx_sched_task_cb(ctx, false);
+ perf_event_swap_task_ctx_data(ctx, next_ctx);
- /*
- * PMU specific parts of task perf context can require
- * additional synchronization. As an example of such
- * synchronization see implementation details of Intel
- * LBR call stack data profiling;
- */
- if (pmu->swap_task_ctx)
- pmu->swap_task_ctx(ctx, next_ctx);
- else
- swap(ctx->task_ctx_data, next_ctx->task_ctx_data);
-
- perf_pmu_enable(pmu);
+ perf_ctx_enable(ctx);
/*
* RCU_INIT_POINTER here is safe because we've not
@@ -3445,8 +3489,8 @@ static void perf_event_context_sched_out
* since those values are always verified under
* ctx->lock which we're now holding.
*/
- RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx);
- RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx);
+ RCU_INIT_POINTER(task->perf_event_ctxp, next_ctx);
+ RCU_INIT_POINTER(next->perf_event_ctxp, ctx);
do_switch = 0;
@@ -3460,37 +3504,39 @@ static void perf_event_context_sched_out
if (do_switch) {
raw_spin_lock(&ctx->lock);
- perf_pmu_disable(pmu);
+ perf_ctx_disable(ctx);
- if (cpuctx->sched_cb_usage && pmu->sched_task)
- pmu->sched_task(ctx, false);
- task_ctx_sched_out(cpuctx, ctx, EVENT_ALL);
+ perf_ctx_sched_task_cb(ctx, false);
+ task_ctx_sched_out(ctx, EVENT_ALL);
- perf_pmu_enable(pmu);
+ perf_ctx_enable(ctx);
raw_spin_unlock(&ctx->lock);
}
}
static DEFINE_PER_CPU(struct list_head, sched_cb_list);
+static DEFINE_PER_CPU(int, perf_sched_cb_usages);
void perf_sched_cb_dec(struct pmu *pmu)
{
- struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+ struct perf_cpu_pmu_context *cpc = this_cpu_ptr(pmu->cpu_pmu_context);
this_cpu_dec(perf_sched_cb_usages);
+ barrier();
- if (!--cpuctx->sched_cb_usage)
- list_del(&cpuctx->sched_cb_entry);
+ if (!--cpc->sched_cb_usage)
+ list_del(&cpc->sched_cb_entry);
}
void perf_sched_cb_inc(struct pmu *pmu)
{
- struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+ struct perf_cpu_pmu_context *cpc = this_cpu_ptr(pmu->cpu_pmu_context);
- if (!cpuctx->sched_cb_usage++)
- list_add(&cpuctx->sched_cb_entry, this_cpu_ptr(&sched_cb_list));
+ if (!cpc->sched_cb_usage++)
+ list_add(&cpc->sched_cb_entry, this_cpu_ptr(&sched_cb_list));
+ barrier();
this_cpu_inc(perf_sched_cb_usages);
}
@@ -3502,19 +3548,21 @@ void perf_sched_cb_inc(struct pmu *pmu)
* PEBS requires this to provide PID/TID information. This requires we flush
* all queued PEBS records before we context switch to a new task.
*/
-static void __perf_pmu_sched_task(struct perf_cpu_context *cpuctx, bool sched_in)
+static void __perf_pmu_sched_task(struct perf_cpu_pmu_context *cpc, bool sched_in)
{
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
struct pmu *pmu;
- pmu = cpuctx->ctx.pmu; /* software PMUs will not have sched_task */
+ pmu = cpc->epc.pmu;
+ /* software PMUs will not have sched_task */
if (WARN_ON_ONCE(!pmu->sched_task))
return;
perf_ctx_lock(cpuctx, cpuctx->task_ctx);
perf_pmu_disable(pmu);
- pmu->sched_task(cpuctx->task_ctx, sched_in);
+ pmu->sched_task(cpc->task_epc, sched_in);
perf_pmu_enable(pmu);
perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
@@ -3524,26 +3572,20 @@ static void perf_pmu_sched_task(struct t
struct task_struct *next,
bool sched_in)
{
- struct perf_cpu_context *cpuctx;
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
+ struct perf_cpu_pmu_context *cpc;
- if (prev == next)
+ /* cpuctx->task_ctx will be handled in perf_event_context_sched_in/out */
+ if (prev == next || cpuctx->task_ctx)
return;
- list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) {
- /* will be handled in perf_event_context_sched_in/out */
- if (cpuctx->task_ctx)
- continue;
-
- __perf_pmu_sched_task(cpuctx, sched_in);
- }
+ list_for_each_entry(cpc, this_cpu_ptr(&sched_cb_list), sched_cb_entry)
+ __perf_pmu_sched_task(cpc, sched_in);
}
static void perf_event_switch(struct task_struct *task,
struct task_struct *next_prev, bool sched_in);
-#define for_each_task_context_nr(ctxn) \
- for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
-
/*
* Called from scheduler to remove the events of the current task,
* with interrupts disabled.
@@ -3558,16 +3600,13 @@ static void perf_event_switch(struct tas
void __perf_event_task_sched_out(struct task_struct *task,
struct task_struct *next)
{
- int ctxn;
-
if (__this_cpu_read(perf_sched_cb_usages))
perf_pmu_sched_task(task, next, false);
if (atomic_read(&nr_switch_events))
perf_event_switch(task, next, false);
- for_each_task_context_nr(ctxn)
- perf_event_context_sched_out(task, ctxn, next);
+ perf_event_context_sched_out(task, next);
/*
* if cgroup events exist on this CPU, then we need
@@ -3578,15 +3617,6 @@ void __perf_event_task_sched_out(struct
perf_cgroup_switch(next);
}
-/*
- * Called with IRQs disabled
- */
-static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
- enum event_type_t event_type)
-{
- ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
-}
-
static bool perf_less_group_idx(const void *l, const void *r)
{
const struct perf_event *le = *(const struct perf_event **)l;
@@ -3618,21 +3648,36 @@ static void __heap_add(struct min_heap *
}
}
-static noinline int visit_groups_merge(struct perf_cpu_context *cpuctx,
+static void __link_epc(struct perf_event_pmu_context *pmu_ctx)
+{
+ struct perf_cpu_pmu_context *cpc;
+
+ if (!pmu_ctx->ctx->task)
+ return;
+
+ cpc = this_cpu_ptr(pmu_ctx->pmu->cpu_pmu_context);
+ WARN_ON_ONCE(cpc->task_epc && cpc->task_epc != pmu_ctx);
+ cpc->task_epc = pmu_ctx;
+}
+
+static noinline int visit_groups_merge(struct perf_event_context *ctx,
struct perf_event_groups *groups, int cpu,
+ struct pmu *pmu,
int (*func)(struct perf_event *, void *),
void *data)
{
#ifdef CONFIG_CGROUP_PERF
struct cgroup_subsys_state *css = NULL;
#endif
+ struct perf_cpu_context *cpuctx = NULL;
/* Space for per CPU and/or any CPU event iterators. */
struct perf_event *itrs[2];
struct min_heap event_heap;
struct perf_event **evt;
int ret;
- if (cpuctx) {
+ if (!ctx->task) {
+ cpuctx = this_cpu_ptr(&cpu_context);
event_heap = (struct min_heap){
.data = cpuctx->heap,
.nr = 0,
@@ -3652,17 +3697,28 @@ static noinline int visit_groups_merge(s
.size = ARRAY_SIZE(itrs),
};
/* Events not within a CPU context may be on any CPU. */
- __heap_add(&event_heap, perf_event_groups_first(groups, -1, NULL));
+ __heap_add(&event_heap, perf_event_groups_first(groups, -1, pmu, NULL));
}
evt = event_heap.data;
- __heap_add(&event_heap, perf_event_groups_first(groups, cpu, NULL));
+ __heap_add(&event_heap, perf_event_groups_first(groups, cpu, pmu, NULL));
#ifdef CONFIG_CGROUP_PERF
for (; css; css = css->parent)
- __heap_add(&event_heap, perf_event_groups_first(groups, cpu, css->cgroup));
+ __heap_add(&event_heap, perf_event_groups_first(groups, cpu, pmu, css->cgroup));
#endif
+ if (event_heap.nr) {
+ /*
+ * XXX: For now, visit_groups_merge() gets called with pmu
+ * pointer never NULL. But these functions needs to be called
+ * once for each pmu if I implement pmu=NULL optimization.
+ */
+ __link_epc((*evt)->pmu_ctx);
+ perf_assert_pmu_disabled((*evt)->pmu_ctx->pmu);
+ }
+
+
min_heapify_all(&event_heap, &perf_min_heap);
while (event_heap.nr) {
@@ -3670,7 +3726,7 @@ static noinline int visit_groups_merge(s
if (ret)
return ret;
- *evt = perf_event_groups_next(*evt);
+ *evt = perf_event_groups_next(*evt, pmu);
if (*evt)
min_heapify(&event_heap, 0, &perf_min_heap);
else
@@ -3712,7 +3768,6 @@ static inline void group_update_userpage
static int merge_sched_in(struct perf_event *event, void *data)
{
struct perf_event_context *ctx = event->ctx;
- struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
int *can_add_hw = data;
if (event->state <= PERF_EVENT_STATE_OFF)
@@ -3721,8 +3776,8 @@ static int merge_sched_in(struct perf_ev
if (!event_filter_match(event))
return 0;
- if (group_can_go_on(event, cpuctx, *can_add_hw)) {
- if (!group_sched_in(event, cpuctx, ctx))
+ if (group_can_go_on(event, *can_add_hw)) {
+ if (!group_sched_in(event, ctx))
list_add_tail(&event->active_list, get_event_list(event));
}
@@ -3732,8 +3787,11 @@ static int merge_sched_in(struct perf_ev
perf_cgroup_event_disable(event, ctx);
perf_event_set_state(event, PERF_EVENT_STATE_ERROR);
} else {
- ctx->rotate_necessary = 1;
- perf_mux_hrtimer_restart(cpuctx);
+ struct perf_cpu_pmu_context *cpc;
+
+ event->pmu_ctx->rotate_necessary = 1;
+ cpc = this_cpu_ptr(event->pmu_ctx->pmu->cpu_pmu_context);
+ perf_mux_hrtimer_restart(cpc);
group_update_userpage(event);
}
}
@@ -3741,39 +3799,67 @@ static int merge_sched_in(struct perf_ev
return 0;
}
-static void
-ctx_pinned_sched_in(struct perf_event_context *ctx,
- struct perf_cpu_context *cpuctx)
+static void ctx_pinned_sched_in(struct perf_event_context *ctx, struct pmu *pmu)
{
+ struct perf_event_pmu_context *pmu_ctx;
int can_add_hw = 1;
- if (ctx != &cpuctx->ctx)
- cpuctx = NULL;
-
- visit_groups_merge(cpuctx, &ctx->pinned_groups,
- smp_processor_id(),
- merge_sched_in, &can_add_hw);
+ if (pmu) {
+ visit_groups_merge(ctx, &ctx->pinned_groups,
+ smp_processor_id(), pmu,
+ merge_sched_in, &can_add_hw);
+ } else {
+ /*
+ * XXX: This can be optimized for per-task context by calling
+ * visit_groups_merge() only once with:
+ * 1) pmu=NULL
+ * 2) Ignoring pmu in perf_event_groups_cmp() when it's NULL
+ * 3) Making can_add_hw a per-pmu variable
+ *
+ * Though, it can not be opimized for per-cpu context because
+ * per-cpu rb-tree consist of pmu-subtrees and pmu-subtrees
+ * consist of cgroup-subtrees. i.e. a cgroup events of same
+ * cgroup but different pmus are seperated out into respective
+ * pmu-subtrees.
+ */
+ list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
+ can_add_hw = 1;
+ visit_groups_merge(ctx, &ctx->pinned_groups,
+ smp_processor_id(), pmu_ctx->pmu,
+ merge_sched_in, &can_add_hw);
+ }
+ }
}
-static void
-ctx_flexible_sched_in(struct perf_event_context *ctx,
- struct perf_cpu_context *cpuctx)
+/* XXX .busy thingy from Peter's patch */
+static void ctx_flexible_sched_in(struct perf_event_context *ctx, struct pmu *pmu)
{
+ struct perf_event_pmu_context *pmu_ctx;
int can_add_hw = 1;
- if (ctx != &cpuctx->ctx)
- cpuctx = NULL;
+ if (pmu) {
+ visit_groups_merge(ctx, &ctx->flexible_groups,
+ smp_processor_id(), pmu,
+ merge_sched_in, &can_add_hw);
+ } else {
+ list_for_each_entry(pmu_ctx, &ctx->pmu_ctx_list, pmu_ctx_entry) {
+ can_add_hw = 1;
+ visit_groups_merge(ctx, &ctx->flexible_groups,
+ smp_processor_id(), pmu_ctx->pmu,
+ merge_sched_in, &can_add_hw);
+ }
+ }
+}
- visit_groups_merge(cpuctx, &ctx->flexible_groups,
- smp_processor_id(),
- merge_sched_in, &can_add_hw);
+static void __pmu_ctx_sched_in(struct perf_event_context *ctx, struct pmu *pmu)
+{
+ ctx_flexible_sched_in(ctx, pmu);
}
static void
-ctx_sched_in(struct perf_event_context *ctx,
- struct perf_cpu_context *cpuctx,
- enum event_type_t event_type)
+ctx_sched_in(struct perf_event_context *ctx, enum event_type_t event_type)
{
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
int is_active = ctx->is_active;
lockdep_assert_held(&ctx->lock);
@@ -3785,6 +3871,7 @@ ctx_sched_in(struct perf_event_context *
/* start ctx time */
__update_context_time(ctx, false);
perf_cgroup_set_timestamp(cpuctx);
+ // XXX ctx->task =? task
/*
* CPU-release for the below ->is_active store,
* see __load_acquire() in perf_event_time_now()
@@ -3807,39 +3894,32 @@ ctx_sched_in(struct perf_event_context *
* in order to give them the best chance of going on.
*/
if (is_active & EVENT_PINNED)
- ctx_pinned_sched_in(ctx, cpuctx);
+ ctx_pinned_sched_in(ctx, NULL);
/* Then walk through the lower prio flexible groups */
if (is_active & EVENT_FLEXIBLE)
- ctx_flexible_sched_in(ctx, cpuctx);
+ ctx_flexible_sched_in(ctx, NULL);
}
-static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
- enum event_type_t event_type)
+static void perf_event_context_sched_in(struct task_struct *task)
{
- struct perf_event_context *ctx = &cpuctx->ctx;
-
- ctx_sched_in(ctx, cpuctx, event_type);
-}
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
+ struct perf_event_context *ctx;
-static void perf_event_context_sched_in(struct perf_event_context *ctx,
- struct task_struct *task)
-{
- struct perf_cpu_context *cpuctx;
- struct pmu *pmu;
+ rcu_read_lock();
+ ctx = rcu_dereference(task->perf_event_ctxp);
+ if (!ctx)
+ goto rcu_unlock;
- cpuctx = __get_cpu_context(ctx);
+ if (cpuctx->task_ctx == ctx) {
+ perf_ctx_lock(cpuctx, ctx);
+ perf_ctx_disable(ctx);
- /*
- * HACK: for HETEROGENEOUS the task context might have switched to a
- * different PMU, force (re)set the context,
- */
- pmu = ctx->pmu = cpuctx->ctx.pmu;
+ perf_ctx_sched_task_cb(ctx, true);
- if (cpuctx->task_ctx == ctx) {
- if (cpuctx->sched_cb_usage)
- __perf_pmu_sched_task(cpuctx, true);
- return;
+ perf_ctx_enable(ctx);
+ perf_ctx_unlock(cpuctx, ctx);
+ goto rcu_unlock;
}
perf_ctx_lock(cpuctx, ctx);
@@ -3850,7 +3930,7 @@ static void perf_event_context_sched_in(
if (!ctx->nr_events)
goto unlock;
- perf_pmu_disable(pmu);
+ perf_ctx_disable(ctx);
/*
* We want to keep the following priority order:
* cpu pinned (that don't need to move), task pinned,
@@ -3859,17 +3939,24 @@ static void perf_event_context_sched_in(
* However, if task's ctx is not carrying any pinned
* events, no need to flip the cpuctx's events around.
*/
- if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree))
- cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
+ if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree)) {
+ perf_ctx_disable(&cpuctx->ctx);
+ ctx_sched_out(&cpuctx->ctx, EVENT_FLEXIBLE);
+ }
+
perf_event_sched_in(cpuctx, ctx);
- if (cpuctx->sched_cb_usage && pmu->sched_task)
- pmu->sched_task(cpuctx->task_ctx, true);
+ perf_ctx_sched_task_cb(cpuctx->task_ctx, true);
- perf_pmu_enable(pmu);
+ if (!RB_EMPTY_ROOT(&ctx->pinned_groups.tree))
+ perf_ctx_enable(&cpuctx->ctx);
+
+ perf_ctx_enable(ctx);
unlock:
perf_ctx_unlock(cpuctx, ctx);
+rcu_unlock:
+ rcu_read_unlock();
}
/*
@@ -3886,16 +3973,7 @@ static void perf_event_context_sched_in(
void __perf_event_task_sched_in(struct task_struct *prev,
struct task_struct *task)
{
- struct perf_event_context *ctx;
- int ctxn;
-
- for_each_task_context_nr(ctxn) {
- ctx = task->perf_event_ctxp[ctxn];
- if (likely(!ctx))
- continue;
-
- perf_event_context_sched_in(ctx, task);
- }
+ perf_event_context_sched_in(task);
if (atomic_read(&nr_switch_events))
perf_event_switch(task, prev, true);
@@ -4014,8 +4092,8 @@ static void perf_adjust_period(struct pe
* 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,
- int needs_unthr)
+static void
+perf_adjust_freq_unthr_context(struct perf_event_context *ctx, bool unthrottle)
{
struct perf_event *event;
struct hw_perf_event *hwc;
@@ -4027,16 +4105,16 @@ static void perf_adjust_freq_unthr_conte
* - context have events in frequency mode (needs freq adjust)
* - there are events to unthrottle on this cpu
*/
- if (!(ctx->nr_freq || needs_unthr))
+ if (!(ctx->nr_freq || unthrottle))
return;
raw_spin_lock(&ctx->lock);
- perf_pmu_disable(ctx->pmu);
list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
if (event->state != PERF_EVENT_STATE_ACTIVE)
continue;
+ // XXX use visit thingy to avoid the -1,cpu match
if (!event_filter_match(event))
continue;
@@ -4077,7 +4155,6 @@ static void perf_adjust_freq_unthr_conte
perf_pmu_enable(event->pmu);
}
- perf_pmu_enable(ctx->pmu);
raw_spin_unlock(&ctx->lock);
}
@@ -4099,72 +4176,111 @@ static void rotate_ctx(struct perf_event
/* pick an event from the flexible_groups to rotate */
static inline struct perf_event *
-ctx_event_to_rotate(struct perf_event_context *ctx)
+ctx_event_to_rotate(struct perf_event_pmu_context *pmu_ctx)
{
struct perf_event *event;
+ struct rb_node *node;
+ struct rb_root *tree;
+ struct __group_key key = {
+ .pmu = pmu_ctx->pmu,
+ };
/* pick the first active flexible event */
- event = list_first_entry_or_null(&ctx->flexible_active,
+ event = list_first_entry_or_null(&pmu_ctx->flexible_active,
struct perf_event, active_list);
+ if (event)
+ goto out;
/* if no active flexible event, pick the first event */
- if (!event) {
- event = rb_entry_safe(rb_first(&ctx->flexible_groups.tree),
- typeof(*event), group_node);
+ tree = &pmu_ctx->ctx->flexible_groups.tree;
+
+ if (!pmu_ctx->ctx->task) {
+ key.cpu = smp_processor_id();
+
+ node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup);
+ if (node)
+ event = __node_2_pe(node);
+ goto out;
}
+ key.cpu = -1;
+ node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup);
+ if (node) {
+ event = __node_2_pe(node);
+ goto out;
+ }
+
+ key.cpu = smp_processor_id();
+ node = rb_find_first(&key, tree, __group_cmp_ignore_cgroup);
+ if (node)
+ event = __node_2_pe(node);
+
+out:
/*
* Unconditionally clear rotate_necessary; if ctx_flexible_sched_in()
* finds there are unschedulable events, it will set it again.
*/
- ctx->rotate_necessary = 0;
+ pmu_ctx->rotate_necessary = 0;
return event;
}
-static bool perf_rotate_context(struct perf_cpu_context *cpuctx)
+static bool perf_rotate_context(struct perf_cpu_pmu_context *cpc)
{
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
+ struct perf_event_pmu_context *cpu_epc, *task_epc = NULL;
struct perf_event *cpu_event = NULL, *task_event = NULL;
struct perf_event_context *task_ctx = NULL;
int cpu_rotate, task_rotate;
+ struct pmu *pmu;
/*
* Since we run this from IRQ context, nobody can install new
* events, thus the event count values are stable.
*/
- cpu_rotate = cpuctx->ctx.rotate_necessary;
+ cpu_epc = &cpc->epc;
+ pmu = cpu_epc->pmu;
+ task_epc = cpc->task_epc;
+
+ cpu_rotate = cpu_epc->rotate_necessary;
task_ctx = cpuctx->task_ctx;
- task_rotate = task_ctx ? task_ctx->rotate_necessary : 0;
+ task_rotate = task_epc ? task_epc->rotate_necessary : 0;
if (!(cpu_rotate || task_rotate))
return false;
perf_ctx_lock(cpuctx, cpuctx->task_ctx);
- perf_pmu_disable(cpuctx->ctx.pmu);
+ perf_pmu_disable(pmu);
if (task_rotate)
- task_event = ctx_event_to_rotate(task_ctx);
+ task_event = ctx_event_to_rotate(task_epc);
if (cpu_rotate)
- cpu_event = ctx_event_to_rotate(&cpuctx->ctx);
+ cpu_event = ctx_event_to_rotate(cpu_epc);
/*
* As per the order given at ctx_resched() first 'pop' task flexible
* and then, if needed CPU flexible.
*/
- if (task_event || (task_ctx && cpu_event))
- ctx_sched_out(task_ctx, cpuctx, EVENT_FLEXIBLE);
- if (cpu_event)
- cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
+ if (task_event || (task_epc && cpu_event)) {
+ update_context_time(task_epc->ctx);
+ __pmu_ctx_sched_out(task_epc, EVENT_FLEXIBLE);
+ }
- if (task_event)
- rotate_ctx(task_ctx, task_event);
- if (cpu_event)
+ if (cpu_event) {
+ update_context_time(&cpuctx->ctx);
+ __pmu_ctx_sched_out(cpu_epc, EVENT_FLEXIBLE);
rotate_ctx(&cpuctx->ctx, cpu_event);
+ __pmu_ctx_sched_in(&cpuctx->ctx, pmu);
+ }
- perf_event_sched_in(cpuctx, task_ctx);
+ if (task_event)
+ rotate_ctx(task_epc->ctx, task_event);
+
+ if (task_event || (task_epc && cpu_event))
+ __pmu_ctx_sched_in(task_epc->ctx, pmu);
- perf_pmu_enable(cpuctx->ctx.pmu);
+ perf_pmu_enable(pmu);
perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
return true;
@@ -4172,8 +4288,8 @@ static bool perf_rotate_context(struct p
void perf_event_task_tick(void)
{
- struct list_head *head = this_cpu_ptr(&active_ctx_list);
- struct perf_event_context *ctx, *tmp;
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
+ struct perf_event_context *ctx;
int throttled;
lockdep_assert_irqs_disabled();
@@ -4182,8 +4298,13 @@ void perf_event_task_tick(void)
throttled = __this_cpu_xchg(perf_throttled_count, 0);
tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
- list_for_each_entry_safe(ctx, tmp, head, active_ctx_list)
- perf_adjust_freq_unthr_context(ctx, throttled);
+ perf_adjust_freq_unthr_context(&cpuctx->ctx, !!throttled);
+
+ rcu_read_lock();
+ ctx = rcu_dereference(current->perf_event_ctxp);
+ if (ctx)
+ perf_adjust_freq_unthr_context(ctx, !!throttled);
+ rcu_read_unlock();
}
static int event_enable_on_exec(struct perf_event *event,
@@ -4205,9 +4326,9 @@ static int event_enable_on_exec(struct p
* Enable all of a task's events that have been marked enable-on-exec.
* This expects task == current.
*/
-static void perf_event_enable_on_exec(int ctxn)
+static void perf_event_enable_on_exec(struct perf_event_context *ctx)
{
- struct perf_event_context *ctx, *clone_ctx = NULL;
+ struct perf_event_context *clone_ctx = NULL;
enum event_type_t event_type = 0;
struct perf_cpu_context *cpuctx;
struct perf_event *event;
@@ -4215,13 +4336,16 @@ static void perf_event_enable_on_exec(in
int enabled = 0;
local_irq_save(flags);
- ctx = current->perf_event_ctxp[ctxn];
- if (!ctx || !ctx->nr_events)
+ if (WARN_ON_ONCE(current->perf_event_ctxp != ctx))
+ goto out;
+
+ if (!ctx->nr_events)
goto out;
- cpuctx = __get_cpu_context(ctx);
+ cpuctx = this_cpu_ptr(&cpu_context);
perf_ctx_lock(cpuctx, ctx);
- ctx_sched_out(ctx, cpuctx, EVENT_TIME);
+ ctx_sched_out(ctx, EVENT_TIME);
+
list_for_each_entry(event, &ctx->event_list, event_entry) {
enabled |= event_enable_on_exec(event, ctx);
event_type |= get_event_type(event);
@@ -4234,7 +4358,7 @@ static void perf_event_enable_on_exec(in
clone_ctx = unclone_ctx(ctx);
ctx_resched(cpuctx, ctx, event_type);
} else {
- ctx_sched_in(ctx, cpuctx, EVENT_TIME);
+ ctx_sched_in(ctx, EVENT_TIME);
}
perf_ctx_unlock(cpuctx, ctx);
@@ -4253,16 +4377,14 @@ static void perf_event_exit_event(struct
* Removes all events from the current task that have been marked
* remove-on-exec, and feeds their values back to parent events.
*/
-static void perf_event_remove_on_exec(int ctxn)
+static void perf_event_remove_on_exec(struct perf_event_context *ctx)
{
- struct perf_event_context *ctx, *clone_ctx = NULL;
+ struct perf_event_context *clone_ctx = NULL;
struct perf_event *event, *next;
unsigned long flags;
bool modified = false;
- ctx = perf_pin_task_context(current, ctxn);
- if (!ctx)
- return;
+ perf_pin_task_context(current);
mutex_lock(&ctx->mutex);
@@ -4326,7 +4448,7 @@ static void __perf_event_read(void *info
struct perf_read_data *data = info;
struct perf_event *sub, *event = data->event;
struct perf_event_context *ctx = event->ctx;
- struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
struct pmu *pmu = event->pmu;
/*
@@ -4552,17 +4674,25 @@ static void __perf_event_init_context(st
{
raw_spin_lock_init(&ctx->lock);
mutex_init(&ctx->mutex);
- INIT_LIST_HEAD(&ctx->active_ctx_list);
+ INIT_LIST_HEAD(&ctx->pmu_ctx_list);
perf_event_groups_init(&ctx->pinned_groups);
perf_event_groups_init(&ctx->flexible_groups);
INIT_LIST_HEAD(&ctx->event_list);
- INIT_LIST_HEAD(&ctx->pinned_active);
- INIT_LIST_HEAD(&ctx->flexible_active);
refcount_set(&ctx->refcount, 1);
}
+static void
+__perf_init_event_pmu_context(struct perf_event_pmu_context *epc, struct pmu *pmu)
+{
+ epc->pmu = pmu;
+ INIT_LIST_HEAD(&epc->pmu_ctx_entry);
+ INIT_LIST_HEAD(&epc->pinned_active);
+ INIT_LIST_HEAD(&epc->flexible_active);
+ atomic_set(&epc->refcount, 1);
+}
+
static struct perf_event_context *
-alloc_perf_context(struct pmu *pmu, struct task_struct *task)
+alloc_perf_context(struct task_struct *task)
{
struct perf_event_context *ctx;
@@ -4573,7 +4703,6 @@ alloc_perf_context(struct pmu *pmu, stru
__perf_event_init_context(ctx);
if (task)
ctx->task = get_task_struct(task);
- ctx->pmu = pmu;
return ctx;
}
@@ -4602,15 +4731,12 @@ find_lively_task_by_vpid(pid_t vpid)
* Returns a matching context with refcount and pincount.
*/
static struct perf_event_context *
-find_get_context(struct pmu *pmu, struct task_struct *task,
- struct perf_event *event)
+find_get_context(struct task_struct *task, struct perf_event *event)
{
struct perf_event_context *ctx, *clone_ctx = NULL;
struct perf_cpu_context *cpuctx;
- void *task_ctx_data = NULL;
unsigned long flags;
- int ctxn, err;
- int cpu = event->cpu;
+ int err;
if (!task) {
/* Must be root to operate on a CPU event: */
@@ -4618,7 +4744,7 @@ find_get_context(struct pmu *pmu, struct
if (err)
return ERR_PTR(err);
- cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
+ cpuctx = per_cpu_ptr(&cpu_context, event->cpu);
ctx = &cpuctx->ctx;
get_ctx(ctx);
raw_spin_lock_irqsave(&ctx->lock, flags);
@@ -4629,43 +4755,22 @@ find_get_context(struct pmu *pmu, struct
}
err = -EINVAL;
- ctxn = pmu->task_ctx_nr;
- if (ctxn < 0)
- goto errout;
-
- if (event->attach_state & PERF_ATTACH_TASK_DATA) {
- task_ctx_data = alloc_task_ctx_data(pmu);
- if (!task_ctx_data) {
- err = -ENOMEM;
- goto errout;
- }
- }
-
retry:
- ctx = perf_lock_task_context(task, ctxn, &flags);
+ ctx = perf_lock_task_context(task, &flags);
if (ctx) {
clone_ctx = unclone_ctx(ctx);
++ctx->pin_count;
- if (task_ctx_data && !ctx->task_ctx_data) {
- ctx->task_ctx_data = task_ctx_data;
- task_ctx_data = NULL;
- }
raw_spin_unlock_irqrestore(&ctx->lock, flags);
if (clone_ctx)
put_ctx(clone_ctx);
} else {
- ctx = alloc_perf_context(pmu, task);
+ ctx = alloc_perf_context(task);
err = -ENOMEM;
if (!ctx)
goto errout;
- if (task_ctx_data) {
- ctx->task_ctx_data = task_ctx_data;
- task_ctx_data = NULL;
- }
-
err = 0;
mutex_lock(&task->perf_event_mutex);
/*
@@ -4674,12 +4779,12 @@ find_get_context(struct pmu *pmu, struct
*/
if (task->flags & PF_EXITING)
err = -ESRCH;
- else if (task->perf_event_ctxp[ctxn])
+ else if (task->perf_event_ctxp)
err = -EAGAIN;
else {
get_ctx(ctx);
++ctx->pin_count;
- rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
+ rcu_assign_pointer(task->perf_event_ctxp, ctx);
}
mutex_unlock(&task->perf_event_mutex);
@@ -4692,14 +4797,117 @@ find_get_context(struct pmu *pmu, struct
}
}
- free_task_ctx_data(pmu, task_ctx_data);
return ctx;
errout:
- free_task_ctx_data(pmu, task_ctx_data);
return ERR_PTR(err);
}
+struct perf_event_pmu_context *
+find_get_pmu_context(struct pmu *pmu, struct perf_event_context *ctx,
+ struct perf_event *event)
+{
+ struct perf_event_pmu_context *new = NULL, *epc;
+ void *task_ctx_data = NULL;
+
+ if (!ctx->task) {
+ struct perf_cpu_pmu_context *cpc;
+
+ cpc = per_cpu_ptr(pmu->cpu_pmu_context, event->cpu);
+ epc = &cpc->epc;
+
+ if (!epc->ctx) {
+ atomic_set(&epc->refcount, 1);
+ epc->embedded = 1;
+ raw_spin_lock_irq(&ctx->lock);
+ list_add(&epc->pmu_ctx_entry, &ctx->pmu_ctx_list);
+ epc->ctx = ctx;
+ raw_spin_unlock_irq(&ctx->lock);
+ } else {
+ WARN_ON_ONCE(epc->ctx != ctx);
+ atomic_inc(&epc->refcount);
+ }
+
+ return epc;
+ }
+
+ new = kzalloc(sizeof(*epc), GFP_KERNEL);
+ if (!new)
+ return ERR_PTR(-ENOMEM);
+
+ if (event->attach_state & PERF_ATTACH_TASK_DATA) {
+ task_ctx_data = alloc_task_ctx_data(pmu);;
+ if (!task_ctx_data) {
+ kfree(new);
+ return ERR_PTR(-ENOMEM);
+ }
+ }
+
+ __perf_init_event_pmu_context(new, pmu);
+
+ raw_spin_lock_irq(&ctx->lock);
+ list_for_each_entry(epc, &ctx->pmu_ctx_list, pmu_ctx_entry) {
+ if (epc->pmu == pmu) {
+ WARN_ON_ONCE(epc->ctx != ctx);
+ atomic_inc(&epc->refcount);
+ goto found_epc;
+ }
+ }
+
+ epc = new;
+ new = NULL;
+
+ list_add(&epc->pmu_ctx_entry, &ctx->pmu_ctx_list);
+ epc->ctx = ctx;
+
+found_epc:
+ if (task_ctx_data && !epc->task_ctx_data) {
+ epc->task_ctx_data = task_ctx_data;
+ task_ctx_data = NULL;
+ ctx->nr_task_data++;
+ }
+ raw_spin_unlock_irq(&ctx->lock);
+
+ free_task_ctx_data(pmu, task_ctx_data);
+ kfree(new);
+
+ return epc;
+}
+
+static void get_pmu_ctx(struct perf_event_pmu_context *epc)
+{
+ WARN_ON_ONCE(!atomic_inc_not_zero(&epc->refcount));
+}
+
+static void put_pmu_ctx(struct perf_event_pmu_context *epc)
+{
+ unsigned long flags;
+
+ if (!atomic_dec_and_test(&epc->refcount))
+ return;
+
+ if (epc->ctx) {
+ struct perf_event_context *ctx = epc->ctx;
+
+ // XXX ctx->mutex
+
+ WARN_ON_ONCE(list_empty(&epc->pmu_ctx_entry));
+ raw_spin_lock_irqsave(&ctx->lock, flags);
+ list_del_init(&epc->pmu_ctx_entry);
+ epc->ctx = NULL;
+ raw_spin_unlock_irqrestore(&ctx->lock, flags);
+ }
+
+ WARN_ON_ONCE(!list_empty(&epc->pinned_active));
+ WARN_ON_ONCE(!list_empty(&epc->flexible_active));
+
+ if (epc->embedded)
+ return;
+
+ kfree(epc->task_ctx_data);
+ kfree(epc);
+}
+
static void perf_event_free_filter(struct perf_event *event);
static void free_event_rcu(struct rcu_head *head)
@@ -4968,6 +5176,9 @@ static void _free_event(struct perf_even
if (event->hw.target)
put_task_struct(event->hw.target);
+ if (event->pmu_ctx)
+ put_pmu_ctx(event->pmu_ctx);
+
/*
* perf_event_free_task() relies on put_ctx() being 'last', in particular
* all task references must be cleaned up.
@@ -5498,7 +5709,7 @@ static void __perf_event_period(struct p
active = (event->state == PERF_EVENT_STATE_ACTIVE);
if (active) {
- perf_pmu_disable(ctx->pmu);
+ perf_pmu_disable(event->pmu);
/*
* We could be throttled; unthrottle now to avoid the tick
* trying to unthrottle while we already re-started the event.
@@ -5514,7 +5725,7 @@ static void __perf_event_period(struct p
if (active) {
event->pmu->start(event, PERF_EF_RELOAD);
- perf_pmu_enable(ctx->pmu);
+ perf_pmu_enable(event->pmu);
}
}
@@ -7606,7 +7817,6 @@ perf_iterate_sb(perf_iterate_f output, v
struct perf_event_context *task_ctx)
{
struct perf_event_context *ctx;
- int ctxn;
rcu_read_lock();
preempt_disable();
@@ -7623,11 +7833,9 @@ perf_iterate_sb(perf_iterate_f output, v
perf_iterate_sb_cpu(output, data);
- for_each_task_context_nr(ctxn) {
- ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
- if (ctx)
- perf_iterate_ctx(ctx, output, data, false);
- }
+ ctx = rcu_dereference(current->perf_event_ctxp);
+ if (ctx)
+ perf_iterate_ctx(ctx, output, data, false);
done:
preempt_enable();
rcu_read_unlock();
@@ -7669,20 +7877,15 @@ static void perf_event_addr_filters_exec
void perf_event_exec(void)
{
struct perf_event_context *ctx;
- int ctxn;
-
- for_each_task_context_nr(ctxn) {
- perf_event_enable_on_exec(ctxn);
- perf_event_remove_on_exec(ctxn);
- rcu_read_lock();
- ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
- if (ctx) {
- perf_iterate_ctx(ctx, perf_event_addr_filters_exec,
- NULL, true);
- }
- rcu_read_unlock();
+ rcu_read_lock();
+ ctx = rcu_dereference(current->perf_event_ctxp);
+ if (ctx) {
+ perf_event_enable_on_exec(ctx);
+ perf_event_remove_on_exec(ctx);
+ perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, true);
}
+ rcu_read_unlock();
}
struct remote_output {
@@ -7722,8 +7925,7 @@ static void __perf_event_output_stop(str
static int __perf_pmu_output_stop(void *info)
{
struct perf_event *event = info;
- struct pmu *pmu = event->ctx->pmu;
- struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
struct remote_output ro = {
.rb = event->rb,
};
@@ -8512,7 +8714,6 @@ static void __perf_addr_filters_adjust(s
static void perf_addr_filters_adjust(struct vm_area_struct *vma)
{
struct perf_event_context *ctx;
- int ctxn;
/*
* Data tracing isn't supported yet and as such there is no need
@@ -8522,13 +8723,9 @@ static void perf_addr_filters_adjust(str
return;
rcu_read_lock();
- for_each_task_context_nr(ctxn) {
- ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
- if (!ctx)
- continue;
-
+ ctx = rcu_dereference(current->perf_event_ctxp);
+ if (ctx)
perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true);
- }
rcu_read_unlock();
}
@@ -9737,10 +9934,13 @@ void perf_tp_event(u16 event_type, u64 c
struct trace_entry *entry = record;
rcu_read_lock();
- ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]);
+ ctx = rcu_dereference(task->perf_event_ctxp);
if (!ctx)
goto unlock;
+ // XXX iterate groups instead, we should be able to
+ // find the subtree for the perf_tracepoint pmu and CPU.
+
list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
if (event->cpu != smp_processor_id())
continue;
@@ -10873,36 +11073,9 @@ static int perf_event_idx_default(struct
return 0;
}
-/*
- * Ensures all contexts with the same task_ctx_nr have the same
- * pmu_cpu_context too.
- */
-static struct perf_cpu_context __percpu *find_pmu_context(int ctxn)
-{
- struct pmu *pmu;
-
- if (ctxn < 0)
- return NULL;
-
- list_for_each_entry(pmu, &pmus, entry) {
- if (pmu->task_ctx_nr == ctxn)
- return pmu->pmu_cpu_context;
- }
-
- return NULL;
-}
-
static void free_pmu_context(struct pmu *pmu)
{
- /*
- * Static contexts such as perf_sw_context have a global lifetime
- * and may be shared between different PMUs. Avoid freeing them
- * when a single PMU is going away.
- */
- if (pmu->task_ctx_nr > perf_invalid_context)
- return;
-
- free_percpu(pmu->pmu_cpu_context);
+ free_percpu(pmu->cpu_pmu_context);
}
/*
@@ -10966,12 +11139,12 @@ perf_event_mux_interval_ms_store(struct
/* update all cpuctx for this PMU */
cpus_read_lock();
for_each_online_cpu(cpu) {
- struct perf_cpu_context *cpuctx;
- cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
- cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
+ struct perf_cpu_pmu_context *cpc;
+ cpc = per_cpu_ptr(pmu->cpu_pmu_context, cpu);
+ cpc->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
cpu_function_call(cpu,
- (remote_function_f)perf_mux_hrtimer_restart, cpuctx);
+ (remote_function_f)perf_mux_hrtimer_restart, cpc);
}
cpus_read_unlock();
mutex_unlock(&mux_interval_mutex);
@@ -11082,47 +11255,19 @@ int perf_pmu_register(struct pmu *pmu, c
}
skip_type:
- if (pmu->task_ctx_nr == perf_hw_context) {
- static int hw_context_taken = 0;
-
- /*
- * Other than systems with heterogeneous CPUs, it never makes
- * sense for two PMUs to share perf_hw_context. PMUs which are
- * uncore must use perf_invalid_context.
- */
- if (WARN_ON_ONCE(hw_context_taken &&
- !(pmu->capabilities & PERF_PMU_CAP_HETEROGENEOUS_CPUS)))
- pmu->task_ctx_nr = perf_invalid_context;
-
- hw_context_taken = 1;
- }
-
- pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
- if (pmu->pmu_cpu_context)
- goto got_cpu_context;
-
ret = -ENOMEM;
- pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
- if (!pmu->pmu_cpu_context)
+ pmu->cpu_pmu_context = alloc_percpu(struct perf_cpu_pmu_context);
+ if (!pmu->cpu_pmu_context)
goto free_dev;
for_each_possible_cpu(cpu) {
- struct perf_cpu_context *cpuctx;
-
- cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
- __perf_event_init_context(&cpuctx->ctx);
- lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
- lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
- cpuctx->ctx.pmu = pmu;
- cpuctx->online = cpumask_test_cpu(cpu, perf_online_mask);
-
- __perf_mux_hrtimer_init(cpuctx, cpu);
+ struct perf_cpu_pmu_context *cpc;
- cpuctx->heap_size = ARRAY_SIZE(cpuctx->heap_default);
- cpuctx->heap = cpuctx->heap_default;
+ cpc = per_cpu_ptr(pmu->cpu_pmu_context, cpu);
+ __perf_init_event_pmu_context(&cpc->epc, pmu);
+ __perf_mux_hrtimer_init(cpc, cpu);
}
-got_cpu_context:
if (!pmu->start_txn) {
if (pmu->pmu_enable) {
/*
@@ -11604,10 +11749,11 @@ perf_event_alloc(struct perf_event_attr
}
/*
- * Disallow uncore-cgroup events, they don't make sense as the cgroup will
- * be different on other CPUs in the uncore mask.
+ * Disallow uncode-task events. Similarly, disallow uncore-cgroup
+ * events (they don't make sense as the cgroup will be different
+ * on other CPUs in the uncore mask).
*/
- if (pmu->task_ctx_nr == perf_invalid_context && cgroup_fd != -1) {
+ if (pmu->task_ctx_nr == perf_invalid_context && (task || cgroup_fd != -1)) {
err = -EINVAL;
goto err_pmu;
}
@@ -11893,15 +12039,6 @@ perf_event_set_output(struct perf_event
return ret;
}
-static void mutex_lock_double(struct mutex *a, struct mutex *b)
-{
- if (b < a)
- swap(a, b);
-
- mutex_lock(a);
- mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
-}
-
static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
{
bool nmi_safe = false;
@@ -11939,37 +12076,6 @@ static int perf_event_set_clock(struct p
return 0;
}
-/*
- * Variation on perf_event_ctx_lock_nested(), except we take two context
- * mutexes.
- */
-static struct perf_event_context *
-__perf_event_ctx_lock_double(struct perf_event *group_leader,
- struct perf_event_context *ctx)
-{
- struct perf_event_context *gctx;
-
-again:
- rcu_read_lock();
- gctx = READ_ONCE(group_leader->ctx);
- if (!refcount_inc_not_zero(&gctx->refcount)) {
- rcu_read_unlock();
- goto again;
- }
- rcu_read_unlock();
-
- mutex_lock_double(&gctx->mutex, &ctx->mutex);
-
- if (group_leader->ctx != gctx) {
- mutex_unlock(&ctx->mutex);
- mutex_unlock(&gctx->mutex);
- put_ctx(gctx);
- goto again;
- }
-
- return gctx;
-}
-
static bool
perf_check_permission(struct perf_event_attr *attr, struct task_struct *task)
{
@@ -12015,9 +12121,10 @@ SYSCALL_DEFINE5(perf_event_open,
pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
{
struct perf_event *group_leader = NULL, *output_event = NULL;
+ struct perf_event_pmu_context *pmu_ctx;
struct perf_event *event, *sibling;
struct perf_event_attr attr;
- struct perf_event_context *ctx, *gctx;
+ struct perf_event_context *ctx;
struct file *event_file = NULL;
struct fd group = {NULL, 0};
struct task_struct *task = NULL;
@@ -12125,6 +12232,8 @@ SYSCALL_DEFINE5(perf_event_open,
goto err_task;
}
+ // XXX premature; what if this is allowed, but we get moved to a PMU
+ // that doesn't have this.
if (is_sampling_event(event)) {
if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
err = -EOPNOTSUPP;
@@ -12147,42 +12256,37 @@ SYSCALL_DEFINE5(perf_event_open,
if (pmu->task_ctx_nr == perf_sw_context)
event->event_caps |= PERF_EV_CAP_SOFTWARE;
- if (group_leader) {
- if (is_software_event(event) &&
- !in_software_context(group_leader)) {
- /*
- * If the event is a sw event, but the group_leader
- * is on hw context.
- *
- * Allow the addition of software events to hw
- * groups, this is safe because software events
- * never fail to schedule.
- */
- pmu = group_leader->ctx->pmu;
- } else if (!is_software_event(event) &&
- is_software_event(group_leader) &&
- (group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) {
- /*
- * In case the group is a pure software group, and we
- * try to add a hardware event, move the whole group to
- * the hardware context.
- */
- move_group = 1;
- }
- }
-
/*
* Get the target context (task or percpu):
*/
- ctx = find_get_context(pmu, task, event);
+ ctx = find_get_context(task, event);
if (IS_ERR(ctx)) {
err = PTR_ERR(ctx);
goto err_alloc;
}
- /*
- * Look up the group leader (we will attach this event to it):
- */
+ mutex_lock(&ctx->mutex);
+
+ if (ctx->task == TASK_TOMBSTONE) {
+ err = -ESRCH;
+ goto err_locked;
+ }
+
+ if (!task) {
+ /*
+ * Check if the @cpu we're creating an event for is online.
+ *
+ * We use the perf_cpu_context::ctx::mutex to serialize against
+ * the hotplug notifiers. See perf_event_{init,exit}_cpu().
+ */
+ struct perf_cpu_context *cpuctx = per_cpu_ptr(&cpu_context, event->cpu);
+
+ if (!cpuctx->online) {
+ err = -ENODEV;
+ goto err_locked;
+ }
+ }
+
if (group_leader) {
err = -EINVAL;
@@ -12191,11 +12295,11 @@ SYSCALL_DEFINE5(perf_event_open,
* becoming part of another group-sibling):
*/
if (group_leader->group_leader != group_leader)
- goto err_context;
+ goto err_locked;
/* All events in a group should have the same clock */
if (group_leader->clock != event->clock)
- goto err_context;
+ goto err_locked;
/*
* Make sure we're both events for the same CPU;
@@ -12203,41 +12307,60 @@ SYSCALL_DEFINE5(perf_event_open,
* you can never concurrently schedule them anyhow.
*/
if (group_leader->cpu != event->cpu)
- goto err_context;
-
- /*
- * Make sure we're both on the same task, or both
- * per-CPU events.
- */
- if (group_leader->ctx->task != ctx->task)
- goto err_context;
+ goto err_locked;
/*
- * Do not allow to attach to a group in a different task
- * or CPU context. If we're moving SW events, we'll fix
- * this up later, so allow that.
- *
- * Racy, not holding group_leader->ctx->mutex, see comment with
- * perf_event_ctx_lock().
+ * Make sure we're both on the same context; either task or cpu.
*/
- if (!move_group && group_leader->ctx != ctx)
- goto err_context;
+ if (group_leader->ctx != ctx)
+ goto err_locked;
/*
* Only a group leader can be exclusive or pinned
*/
if (attr.exclusive || attr.pinned)
- goto err_context;
+ goto err_locked;
+
+ if (is_software_event(event) &&
+ !in_software_context(group_leader)) {
+ /*
+ * If the event is a sw event, but the group_leader
+ * is on hw context.
+ *
+ * Allow the addition of software events to hw
+ * groups, this is safe because software events
+ * never fail to schedule.
+ */
+ pmu = group_leader->pmu_ctx->pmu;
+ } else if (!is_software_event(event) &&
+ is_software_event(group_leader) &&
+ (group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) {
+ /*
+ * In case the group is a pure software group, and we
+ * try to add a hardware event, move the whole group to
+ * the hardware context.
+ */
+ move_group = 1;
+ }
}
+ /*
+ * Now that we're certain of the pmu; find the pmu_ctx.
+ */
+ pmu_ctx = find_get_pmu_context(pmu, ctx, event);
+ if (IS_ERR(pmu_ctx)) {
+ err = PTR_ERR(pmu_ctx);
+ goto err_locked;
+ }
+ event->pmu_ctx = pmu_ctx;
+
if (output_event) {
err = perf_event_set_output(event, output_event);
if (err)
goto err_context;
}
- event_file = anon_inode_getfile("[perf_event]", &perf_fops, event,
- f_flags);
+ event_file = anon_inode_getfile("[perf_event]", &perf_fops, event, f_flags);
if (IS_ERR(event_file)) {
err = PTR_ERR(event_file);
event_file = NULL;
@@ -12260,59 +12383,6 @@ SYSCALL_DEFINE5(perf_event_open,
goto err_cred;
}
- if (move_group) {
- gctx = __perf_event_ctx_lock_double(group_leader, ctx);
-
- if (gctx->task == TASK_TOMBSTONE) {
- err = -ESRCH;
- goto err_locked;
- }
-
- /*
- * Check if we raced against another sys_perf_event_open() call
- * moving the software group underneath us.
- */
- if (!(group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) {
- /*
- * If someone moved the group out from under us, check
- * if this new event wound up on the same ctx, if so
- * its the regular !move_group case, otherwise fail.
- */
- if (gctx != ctx) {
- err = -EINVAL;
- goto err_locked;
- } else {
- perf_event_ctx_unlock(group_leader, gctx);
- move_group = 0;
- goto not_move_group;
- }
- }
-
- /*
- * Failure to create exclusive events returns -EBUSY.
- */
- err = -EBUSY;
- if (!exclusive_event_installable(group_leader, ctx))
- goto err_locked;
-
- for_each_sibling_event(sibling, group_leader) {
- if (!exclusive_event_installable(sibling, ctx))
- goto err_locked;
- }
- } else {
- mutex_lock(&ctx->mutex);
-
- /*
- * Now that we hold ctx->lock, (re)validate group_leader->ctx == ctx,
- * see the group_leader && !move_group test earlier.
- */
- if (group_leader && group_leader->ctx != ctx) {
- err = -EINVAL;
- goto err_locked;
- }
- }
-not_move_group:
-
if (ctx->task == TASK_TOMBSTONE) {
err = -ESRCH;
goto err_locked;
@@ -12350,7 +12420,7 @@ SYSCALL_DEFINE5(perf_event_open,
*/
if (!exclusive_event_installable(event, ctx)) {
err = -EBUSY;
- goto err_locked;
+ goto err_cred;
}
WARN_ON_ONCE(ctx->parent_ctx);
@@ -12361,25 +12431,15 @@ SYSCALL_DEFINE5(perf_event_open,
*/
if (move_group) {
- /*
- * See perf_event_ctx_lock() for comments on the details
- * of swizzling perf_event::ctx.
- */
perf_remove_from_context(group_leader, 0);
- put_ctx(gctx);
+ put_pmu_ctx(group_leader->pmu_ctx);
for_each_sibling_event(sibling, group_leader) {
perf_remove_from_context(sibling, 0);
- put_ctx(gctx);
+ put_pmu_ctx(sibling->pmu_ctx);
}
/*
- * Wait for everybody to stop referencing the events through
- * the old lists, before installing it on new lists.
- */
- synchronize_rcu();
-
- /*
* Install the group siblings before the group leader.
*
* Because a group leader will try and install the entire group
@@ -12390,9 +12450,10 @@ SYSCALL_DEFINE5(perf_event_open,
* reachable through the group lists.
*/
for_each_sibling_event(sibling, group_leader) {
+ sibling->pmu_ctx = pmu_ctx;
+ get_pmu_ctx(pmu_ctx);
perf_event__state_init(sibling);
perf_install_in_context(ctx, sibling, sibling->cpu);
- get_ctx(ctx);
}
/*
@@ -12400,9 +12461,10 @@ SYSCALL_DEFINE5(perf_event_open,
* event. What we want here is event in the initial
* startup state, ready to be add into new context.
*/
+ group_leader->pmu_ctx = pmu_ctx;
+ get_pmu_ctx(pmu_ctx);
perf_event__state_init(group_leader);
perf_install_in_context(ctx, group_leader, group_leader->cpu);
- get_ctx(ctx);
}
/*
@@ -12419,8 +12481,6 @@ SYSCALL_DEFINE5(perf_event_open,
perf_install_in_context(ctx, event, event->cpu);
perf_unpin_context(ctx);
- if (move_group)
- perf_event_ctx_unlock(group_leader, gctx);
mutex_unlock(&ctx->mutex);
if (task) {
@@ -12442,16 +12502,15 @@ SYSCALL_DEFINE5(perf_event_open,
fd_install(event_fd, event_file);
return event_fd;
-err_locked:
- if (move_group)
- perf_event_ctx_unlock(group_leader, gctx);
- mutex_unlock(&ctx->mutex);
err_cred:
if (task)
up_read(&task->signal->exec_update_lock);
err_file:
fput(event_file);
err_context:
+ /* event->pmu_ctx freed by free_event() */
+err_locked:
+ mutex_unlock(&ctx->mutex);
perf_unpin_context(ctx);
put_ctx(ctx);
err_alloc:
@@ -12486,8 +12545,10 @@ perf_event_create_kernel_counter(struct
perf_overflow_handler_t overflow_handler,
void *context)
{
+ struct perf_event_pmu_context *pmu_ctx;
struct perf_event_context *ctx;
struct perf_event *event;
+ struct pmu *pmu;
int err;
/*
@@ -12506,16 +12567,32 @@ perf_event_create_kernel_counter(struct
/* Mark owner so we could distinguish it from user events. */
event->owner = TASK_TOMBSTONE;
+ pmu = event->pmu;
+
+ if (pmu->task_ctx_nr < 0 && task) {
+ err = -EINVAL;
+ goto err_alloc;
+ }
+
+ if (pmu->task_ctx_nr == perf_sw_context)
+ event->event_caps |= PERF_EV_CAP_SOFTWARE;
/*
* Get the target context (task or percpu):
*/
- ctx = find_get_context(event->pmu, task, event);
+ ctx = find_get_context(task, event);
if (IS_ERR(ctx)) {
err = PTR_ERR(ctx);
- goto err_free;
+ goto err_alloc;
}
+ pmu_ctx = find_get_pmu_context(pmu, ctx, event);
+ if (IS_ERR(pmu_ctx)) {
+ err = PTR_ERR(pmu_ctx);
+ goto err_ctx;
+ }
+ event->pmu_ctx = pmu_ctx;
+
WARN_ON_ONCE(ctx->parent_ctx);
mutex_lock(&ctx->mutex);
if (ctx->task == TASK_TOMBSTONE) {
@@ -12551,9 +12628,10 @@ perf_event_create_kernel_counter(struct
err_unlock:
mutex_unlock(&ctx->mutex);
+err_ctx:
perf_unpin_context(ctx);
put_ctx(ctx);
-err_free:
+err_alloc:
free_event(event);
err:
return ERR_PTR(err);
@@ -12562,6 +12640,7 @@ EXPORT_SYMBOL_GPL(perf_event_create_kern
void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
{
+#if 0 // XXX buggered - cpu hotplug, who cares
struct perf_event_context *src_ctx;
struct perf_event_context *dst_ctx;
struct perf_event *event, *tmp;
@@ -12622,6 +12701,7 @@ void perf_pmu_migrate_context(struct pmu
}
mutex_unlock(&dst_ctx->mutex);
mutex_unlock(&src_ctx->mutex);
+#endif
}
EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
@@ -12699,14 +12779,14 @@ perf_event_exit_event(struct perf_event
perf_event_wakeup(event);
}
-static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
+static void perf_event_exit_task_context(struct task_struct *child)
{
struct perf_event_context *child_ctx, *clone_ctx = NULL;
struct perf_event *child_event, *next;
WARN_ON_ONCE(child != current);
- child_ctx = perf_pin_task_context(child, ctxn);
+ child_ctx = perf_pin_task_context(child);
if (!child_ctx)
return;
@@ -12728,13 +12808,13 @@ static void perf_event_exit_task_context
* in.
*/
raw_spin_lock_irq(&child_ctx->lock);
- task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx, EVENT_ALL);
+ task_ctx_sched_out(child_ctx, EVENT_ALL);
/*
* Now that the context is inactive, destroy the task <-> ctx relation
* and mark the context dead.
*/
- RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL);
+ RCU_INIT_POINTER(child->perf_event_ctxp, NULL);
put_ctx(child_ctx); /* cannot be last */
WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE);
put_task_struct(current); /* cannot be last */
@@ -12769,7 +12849,6 @@ static void perf_event_exit_task_context
void perf_event_exit_task(struct task_struct *child)
{
struct perf_event *event, *tmp;
- int ctxn;
mutex_lock(&child->perf_event_mutex);
list_for_each_entry_safe(event, tmp, &child->perf_event_list,
@@ -12785,8 +12864,7 @@ void perf_event_exit_task(struct task_st
}
mutex_unlock(&child->perf_event_mutex);
- for_each_task_context_nr(ctxn)
- perf_event_exit_task_context(child, ctxn);
+ perf_event_exit_task_context(child);
/*
* The perf_event_exit_task_context calls perf_event_task
@@ -12829,56 +12907,51 @@ void perf_event_free_task(struct task_st
{
struct perf_event_context *ctx;
struct perf_event *event, *tmp;
- int ctxn;
- for_each_task_context_nr(ctxn) {
- ctx = task->perf_event_ctxp[ctxn];
- if (!ctx)
- continue;
+ ctx = rcu_dereference(task->perf_event_ctxp);
+ if (!ctx)
+ return;
- mutex_lock(&ctx->mutex);
- raw_spin_lock_irq(&ctx->lock);
- /*
- * Destroy the task <-> ctx relation and mark the context dead.
- *
- * This is important because even though the task hasn't been
- * exposed yet the context has been (through child_list).
- */
- RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], NULL);
- WRITE_ONCE(ctx->task, TASK_TOMBSTONE);
- put_task_struct(task); /* cannot be last */
- raw_spin_unlock_irq(&ctx->lock);
+ mutex_lock(&ctx->mutex);
+ raw_spin_lock_irq(&ctx->lock);
+ /*
+ * Destroy the task <-> ctx relation and mark the context dead.
+ *
+ * This is important because even though the task hasn't been
+ * exposed yet the context has been (through child_list).
+ */
+ RCU_INIT_POINTER(task->perf_event_ctxp, NULL);
+ WRITE_ONCE(ctx->task, TASK_TOMBSTONE);
+ put_task_struct(task); /* cannot be last */
+ raw_spin_unlock_irq(&ctx->lock);
- list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry)
- perf_free_event(event, ctx);
- mutex_unlock(&ctx->mutex);
+ list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry)
+ perf_free_event(event, ctx);
- /*
- * perf_event_release_kernel() could've stolen some of our
- * child events and still have them on its free_list. In that
- * case we must wait for these events to have been freed (in
- * particular all their references to this task must've been
- * dropped).
- *
- * Without this copy_process() will unconditionally free this
- * task (irrespective of its reference count) and
- * _free_event()'s put_task_struct(event->hw.target) will be a
- * use-after-free.
- *
- * Wait for all events to drop their context reference.
- */
- wait_var_event(&ctx->refcount, refcount_read(&ctx->refcount) == 1);
- put_ctx(ctx); /* must be last */
- }
+ mutex_unlock(&ctx->mutex);
+
+ /*
+ * perf_event_release_kernel() could've stolen some of our
+ * child events and still have them on its free_list. In that
+ * case we must wait for these events to have been freed (in
+ * particular all their references to this task must've been
+ * dropped).
+ *
+ * Without this copy_process() will unconditionally free this
+ * task (irrespective of its reference count) and
+ * _free_event()'s put_task_struct(event->hw.target) will be a
+ * use-after-free.
+ *
+ * Wait for all events to drop their context reference.
+ */
+ wait_var_event(&ctx->refcount, refcount_read(&ctx->refcount) == 1);
+ put_ctx(ctx); /* must be last */
}
void perf_event_delayed_put(struct task_struct *task)
{
- int ctxn;
-
- for_each_task_context_nr(ctxn)
- WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
+ WARN_ON_ONCE(task->perf_event_ctxp);
}
struct file *perf_event_get(unsigned int fd)
@@ -12928,6 +13001,7 @@ inherit_event(struct perf_event *parent_
struct perf_event_context *child_ctx)
{
enum perf_event_state parent_state = parent_event->state;
+ struct perf_event_pmu_context *pmu_ctx;
struct perf_event *child_event;
unsigned long flags;
@@ -12948,17 +13022,12 @@ inherit_event(struct perf_event *parent_
if (IS_ERR(child_event))
return child_event;
-
- if ((child_event->attach_state & PERF_ATTACH_TASK_DATA) &&
- !child_ctx->task_ctx_data) {
- struct pmu *pmu = child_event->pmu;
-
- child_ctx->task_ctx_data = alloc_task_ctx_data(pmu);
- if (!child_ctx->task_ctx_data) {
- free_event(child_event);
- return ERR_PTR(-ENOMEM);
- }
+ pmu_ctx = find_get_pmu_context(child_event->pmu, child_ctx, child_event);
+ if (!pmu_ctx) {
+ free_event(child_event);
+ return NULL;
}
+ child_event->pmu_ctx = pmu_ctx;
/*
* is_orphaned_event() and list_add_tail(&parent_event->child_list)
@@ -13081,11 +13150,11 @@ static int inherit_group(struct perf_eve
static int
inherit_task_group(struct perf_event *event, struct task_struct *parent,
struct perf_event_context *parent_ctx,
- struct task_struct *child, int ctxn,
+ struct task_struct *child,
u64 clone_flags, int *inherited_all)
{
- int ret;
struct perf_event_context *child_ctx;
+ int ret;
if (!event->attr.inherit ||
(event->attr.inherit_thread && !(clone_flags & CLONE_THREAD)) ||
@@ -13095,7 +13164,7 @@ inherit_task_group(struct perf_event *ev
return 0;
}
- child_ctx = child->perf_event_ctxp[ctxn];
+ child_ctx = child->perf_event_ctxp;
if (!child_ctx) {
/*
* This is executed from the parent task context, so
@@ -13103,16 +13172,14 @@ inherit_task_group(struct perf_event *ev
* First allocate and initialize a context for the
* child.
*/
- child_ctx = alloc_perf_context(parent_ctx->pmu, child);
+ child_ctx = alloc_perf_context(child);
if (!child_ctx)
return -ENOMEM;
- child->perf_event_ctxp[ctxn] = child_ctx;
+ child->perf_event_ctxp = child_ctx;
}
- ret = inherit_group(event, parent, parent_ctx,
- child, child_ctx);
-
+ ret = inherit_group(event, parent, parent_ctx, child, child_ctx);
if (ret)
*inherited_all = 0;
@@ -13122,8 +13189,7 @@ inherit_task_group(struct perf_event *ev
/*
* Initialize the perf_event context in task_struct
*/
-static int perf_event_init_context(struct task_struct *child, int ctxn,
- u64 clone_flags)
+static int perf_event_init_context(struct task_struct *child, u64 clone_flags)
{
struct perf_event_context *child_ctx, *parent_ctx;
struct perf_event_context *cloned_ctx;
@@ -13133,14 +13199,14 @@ static int perf_event_init_context(struc
unsigned long flags;
int ret = 0;
- if (likely(!parent->perf_event_ctxp[ctxn]))
+ if (likely(!parent->perf_event_ctxp))
return 0;
/*
* If the parent's context is a clone, pin it so it won't get
* swapped under us.
*/
- parent_ctx = perf_pin_task_context(parent, ctxn);
+ parent_ctx = perf_pin_task_context(parent);
if (!parent_ctx)
return 0;
@@ -13163,8 +13229,7 @@ static int perf_event_init_context(struc
*/
perf_event_groups_for_each(event, &parent_ctx->pinned_groups) {
ret = inherit_task_group(event, parent, parent_ctx,
- child, ctxn, clone_flags,
- &inherited_all);
+ child, clone_flags, &inherited_all);
if (ret)
goto out_unlock;
}
@@ -13180,8 +13245,7 @@ static int perf_event_init_context(struc
perf_event_groups_for_each(event, &parent_ctx->flexible_groups) {
ret = inherit_task_group(event, parent, parent_ctx,
- child, ctxn, clone_flags,
- &inherited_all);
+ child, clone_flags, &inherited_all);
if (ret)
goto out_unlock;
}
@@ -13189,7 +13253,7 @@ static int perf_event_init_context(struc
raw_spin_lock_irqsave(&parent_ctx->lock, flags);
parent_ctx->rotate_disable = 0;
- child_ctx = child->perf_event_ctxp[ctxn];
+ child_ctx = child->perf_event_ctxp;
if (child_ctx && inherited_all) {
/*
@@ -13225,18 +13289,16 @@ static int perf_event_init_context(struc
*/
int perf_event_init_task(struct task_struct *child, u64 clone_flags)
{
- int ctxn, ret;
+ int ret;
- memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
+ child->perf_event_ctxp = NULL;
mutex_init(&child->perf_event_mutex);
INIT_LIST_HEAD(&child->perf_event_list);
- for_each_task_context_nr(ctxn) {
- ret = perf_event_init_context(child, ctxn, clone_flags);
- if (ret) {
- perf_event_free_task(child);
- return ret;
- }
+ ret = perf_event_init_context(child, clone_flags);
+ if (ret) {
+ perf_event_free_task(child);
+ return ret;
}
return 0;
@@ -13245,6 +13307,7 @@ int perf_event_init_task(struct task_str
static void __init perf_event_init_all_cpus(void)
{
struct swevent_htable *swhash;
+ struct perf_cpu_context *cpuctx;
int cpu;
zalloc_cpumask_var(&perf_online_mask, GFP_KERNEL);
@@ -13252,7 +13315,6 @@ static void __init perf_event_init_all_c
for_each_possible_cpu(cpu) {
swhash = &per_cpu(swevent_htable, cpu);
mutex_init(&swhash->hlist_mutex);
- INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu));
INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu));
raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu));
@@ -13261,6 +13323,14 @@ static void __init perf_event_init_all_c
INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list, cpu));
#endif
INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu));
+
+ cpuctx = per_cpu_ptr(&cpu_context, cpu);
+ __perf_event_init_context(&cpuctx->ctx);
+ lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
+ lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
+ cpuctx->online = cpumask_test_cpu(cpu, perf_online_mask);
+ cpuctx->heap_size = ARRAY_SIZE(cpuctx->heap_default);
+ cpuctx->heap = cpuctx->heap_default;
}
}
@@ -13282,12 +13352,12 @@ static void perf_swevent_init_cpu(unsign
#if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
static void __perf_event_exit_context(void *__info)
{
+ struct perf_cpu_context *cpuctx = this_cpu_ptr(&cpu_context);
struct perf_event_context *ctx = __info;
- struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
struct perf_event *event;
raw_spin_lock(&ctx->lock);
- ctx_sched_out(ctx, cpuctx, EVENT_TIME);
+ ctx_sched_out(ctx, EVENT_TIME);
list_for_each_entry(event, &ctx->event_list, event_entry)
__perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP);
raw_spin_unlock(&ctx->lock);
@@ -13297,18 +13367,16 @@ static void perf_event_exit_cpu_context(
{
struct perf_cpu_context *cpuctx;
struct perf_event_context *ctx;
- struct pmu *pmu;
+ // XXX simplify cpuctx->online
mutex_lock(&pmus_lock);
- list_for_each_entry(pmu, &pmus, entry) {
- cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
- ctx = &cpuctx->ctx;
+ cpuctx = per_cpu_ptr(&cpu_context, cpu);
+ ctx = &cpuctx->ctx;
- mutex_lock(&ctx->mutex);
- smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
- cpuctx->online = 0;
- mutex_unlock(&ctx->mutex);
- }
+ mutex_lock(&ctx->mutex);
+ smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
+ cpuctx->online = 0;
+ mutex_unlock(&ctx->mutex);
cpumask_clear_cpu(cpu, perf_online_mask);
mutex_unlock(&pmus_lock);
}
@@ -13322,20 +13390,17 @@ int perf_event_init_cpu(unsigned int cpu
{
struct perf_cpu_context *cpuctx;
struct perf_event_context *ctx;
- struct pmu *pmu;
perf_swevent_init_cpu(cpu);
mutex_lock(&pmus_lock);
cpumask_set_cpu(cpu, perf_online_mask);
- list_for_each_entry(pmu, &pmus, entry) {
- cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
- ctx = &cpuctx->ctx;
+ cpuctx = per_cpu_ptr(&cpu_context, cpu);
+ ctx = &cpuctx->ctx;
- mutex_lock(&ctx->mutex);
- cpuctx->online = 1;
- mutex_unlock(&ctx->mutex);
- }
+ mutex_lock(&ctx->mutex);
+ cpuctx->online = 1;
+ mutex_unlock(&ctx->mutex);
mutex_unlock(&pmus_lock);
return 0;
next prev parent reply other threads:[~2022-06-13 16:49 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-13 13:47 [RFC v2] perf: Rewrite core context handling Ravi Bangoria
2022-01-13 19:06 ` [RFC PATCH] perf: find_get_pmu_context can be static kernel test robot
2022-01-13 19:15 ` [RFC v2] perf: Rewrite core context handling kernel test robot
2022-01-17 7:18 ` [perf] f7cf7134e4: WARNING:at_kernel/events/core.c:#__pmu_ctx_sched_out kernel test robot
2022-01-17 7:18 ` kernel test robot
2022-01-31 4:43 ` [RFC v2] perf: Rewrite core context handling Ravi Bangoria
2022-06-13 14:35 ` Peter Zijlstra [this message]
2022-06-13 14:36 ` Peter Zijlstra
2022-06-13 14:38 ` Peter Zijlstra
2022-08-02 6:11 ` Ravi Bangoria
2022-08-22 15:29 ` Peter Zijlstra
2022-08-22 15:43 ` Peter Zijlstra
2022-08-22 16:37 ` Ravi Bangoria
2022-08-23 4:20 ` Ravi Bangoria
2022-08-29 3:54 ` Ravi Bangoria
2022-08-23 6:30 ` Peter Zijlstra
2022-08-29 4:00 ` Ravi Bangoria
2022-08-29 11:58 ` Peter Zijlstra
2022-08-22 16:52 ` Peter Zijlstra
2022-08-23 4:57 ` Ravi Bangoria
2022-06-13 14:41 ` Peter Zijlstra
2022-08-22 14:38 ` Ravi Bangoria
2022-06-13 14:43 ` Peter Zijlstra
2022-08-02 6:16 ` Ravi Bangoria
2022-08-23 8:57 ` Peter Zijlstra
2022-08-24 5:07 ` Ravi Bangoria
2022-08-24 7:27 ` Peter Zijlstra
2022-08-24 7:53 ` Ravi Bangoria
2022-06-13 14:55 ` Peter Zijlstra
2022-08-02 6:10 ` Ravi Bangoria
2022-08-22 16:44 ` Peter Zijlstra
2022-08-23 4:46 ` Ravi Bangoria
2022-06-17 13:36 ` Peter Zijlstra
2022-08-24 10:13 ` Peter Zijlstra
2022-06-27 4:18 ` Ravi Bangoria
2022-08-02 6:06 ` Ravi Bangoria
2022-08-24 12:15 ` Peter Zijlstra
2022-08-24 14:59 ` Peter Zijlstra
2022-08-25 5:39 ` Ravi Bangoria
2022-08-25 9:17 ` Peter Zijlstra
2022-08-25 11:03 ` Ravi Bangoria
2022-08-02 6:13 ` Ravi Bangoria
2022-08-23 7:10 ` Peter Zijlstra
2022-08-02 6:17 ` Ravi Bangoria
2022-08-23 7:26 ` Peter Zijlstra
2022-08-23 15:14 ` Ravi Bangoria
2022-08-22 14:40 ` Ravi Bangoria
2022-01-14 21:48 kernel test robot
2022-01-18 6:01 ` kernel test robot
2022-01-18 6:01 ` kernel test robot
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