Commit 4dc0da86 authored by Avi Kivity's avatar Avi Kivity Committed by Ingo Molnar

perf: Add context field to perf_event

The perf_event overflow handler does not receive any caller-derived
argument, so many callers need to resort to looking up the perf_event
in their local data structure.  This is ugly and doesn't scale if a
single callback services many perf_events.

Fix by adding a context parameter to perf_event_create_kernel_counter()
(and derived hardware breakpoints APIs) and storing it in the perf_event.
The field can be accessed from the callback as event->overflow_handler_context.
All callers are updated.
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 89d6c0b5
...@@ -479,7 +479,8 @@ static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type) ...@@ -479,7 +479,8 @@ static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
attr.bp_type = type; attr.bp_type = type;
attr.disabled = 1; attr.disabled = 1;
return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, tsk); return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
tsk);
} }
static int ptrace_gethbpregs(struct task_struct *tsk, long num, static int ptrace_gethbpregs(struct task_struct *tsk, long num,
......
...@@ -973,7 +973,7 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, ...@@ -973,7 +973,7 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
&attr.bp_type); &attr.bp_type);
thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr, thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
ptrace_triggered, task); ptrace_triggered, NULL, task);
if (IS_ERR(bp)) { if (IS_ERR(bp)) {
thread->ptrace_bps[0] = NULL; thread->ptrace_bps[0] = NULL;
ptrace_put_breakpoints(task); ptrace_put_breakpoints(task);
......
...@@ -91,7 +91,8 @@ static int set_single_step(struct task_struct *tsk, unsigned long addr) ...@@ -91,7 +91,8 @@ static int set_single_step(struct task_struct *tsk, unsigned long addr)
attr.bp_len = HW_BREAKPOINT_LEN_2; attr.bp_len = HW_BREAKPOINT_LEN_2;
attr.bp_type = HW_BREAKPOINT_R; attr.bp_type = HW_BREAKPOINT_R;
bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk); bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
NULL, tsk);
if (IS_ERR(bp)) if (IS_ERR(bp))
return PTR_ERR(bp); return PTR_ERR(bp);
......
...@@ -638,7 +638,7 @@ void kgdb_arch_late(void) ...@@ -638,7 +638,7 @@ void kgdb_arch_late(void)
for (i = 0; i < HBP_NUM; i++) { for (i = 0; i < HBP_NUM; i++) {
if (breakinfo[i].pev) if (breakinfo[i].pev)
continue; continue;
breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL); breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL, NULL);
if (IS_ERR((void * __force)breakinfo[i].pev)) { if (IS_ERR((void * __force)breakinfo[i].pev)) {
printk(KERN_ERR "kgdb: Could not allocate hw" printk(KERN_ERR "kgdb: Could not allocate hw"
"breakpoints\nDisabling the kernel debugger\n"); "breakpoints\nDisabling the kernel debugger\n");
......
...@@ -715,7 +715,8 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr, ...@@ -715,7 +715,8 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
attr.bp_type = HW_BREAKPOINT_W; attr.bp_type = HW_BREAKPOINT_W;
attr.disabled = 1; attr.disabled = 1;
bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk); bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
NULL, tsk);
/* /*
* CHECKME: the previous code returned -EIO if the addr wasn't * CHECKME: the previous code returned -EIO if the addr wasn't
......
...@@ -79,7 +79,7 @@ static int op_create_counter(int cpu, int event) ...@@ -79,7 +79,7 @@ static int op_create_counter(int cpu, int event)
pevent = perf_event_create_kernel_counter(&counter_config[event].attr, pevent = perf_event_create_kernel_counter(&counter_config[event].attr,
cpu, NULL, cpu, NULL,
op_overflow_handler); op_overflow_handler, NULL);
if (IS_ERR(pevent)) if (IS_ERR(pevent))
return PTR_ERR(pevent); return PTR_ERR(pevent);
......
...@@ -73,6 +73,7 @@ static inline unsigned long hw_breakpoint_len(struct perf_event *bp) ...@@ -73,6 +73,7 @@ static inline unsigned long hw_breakpoint_len(struct perf_event *bp)
extern struct perf_event * extern struct perf_event *
register_user_hw_breakpoint(struct perf_event_attr *attr, register_user_hw_breakpoint(struct perf_event_attr *attr,
perf_overflow_handler_t triggered, perf_overflow_handler_t triggered,
void *context,
struct task_struct *tsk); struct task_struct *tsk);
/* FIXME: only change from the attr, and don't unregister */ /* FIXME: only change from the attr, and don't unregister */
...@@ -85,11 +86,13 @@ modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr); ...@@ -85,11 +86,13 @@ modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr);
extern struct perf_event * extern struct perf_event *
register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr, register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
perf_overflow_handler_t triggered, perf_overflow_handler_t triggered,
void *context,
int cpu); int cpu);
extern struct perf_event * __percpu * extern struct perf_event * __percpu *
register_wide_hw_breakpoint(struct perf_event_attr *attr, register_wide_hw_breakpoint(struct perf_event_attr *attr,
perf_overflow_handler_t triggered); perf_overflow_handler_t triggered,
void *context);
extern int register_perf_hw_breakpoint(struct perf_event *bp); extern int register_perf_hw_breakpoint(struct perf_event *bp);
extern int __register_perf_hw_breakpoint(struct perf_event *bp); extern int __register_perf_hw_breakpoint(struct perf_event *bp);
...@@ -115,6 +118,7 @@ static inline int __init init_hw_breakpoint(void) { return 0; } ...@@ -115,6 +118,7 @@ static inline int __init init_hw_breakpoint(void) { return 0; }
static inline struct perf_event * static inline struct perf_event *
register_user_hw_breakpoint(struct perf_event_attr *attr, register_user_hw_breakpoint(struct perf_event_attr *attr,
perf_overflow_handler_t triggered, perf_overflow_handler_t triggered,
void *context,
struct task_struct *tsk) { return NULL; } struct task_struct *tsk) { return NULL; }
static inline int static inline int
modify_user_hw_breakpoint(struct perf_event *bp, modify_user_hw_breakpoint(struct perf_event *bp,
...@@ -122,10 +126,12 @@ modify_user_hw_breakpoint(struct perf_event *bp, ...@@ -122,10 +126,12 @@ modify_user_hw_breakpoint(struct perf_event *bp,
static inline struct perf_event * static inline struct perf_event *
register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr, register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
perf_overflow_handler_t triggered, perf_overflow_handler_t triggered,
void *context,
int cpu) { return NULL; } int cpu) { return NULL; }
static inline struct perf_event * __percpu * static inline struct perf_event * __percpu *
register_wide_hw_breakpoint(struct perf_event_attr *attr, register_wide_hw_breakpoint(struct perf_event_attr *attr,
perf_overflow_handler_t triggered) { return NULL; } perf_overflow_handler_t triggered,
void *context) { return NULL; }
static inline int static inline int
register_perf_hw_breakpoint(struct perf_event *bp) { return -ENOSYS; } register_perf_hw_breakpoint(struct perf_event *bp) { return -ENOSYS; }
static inline int static inline int
......
...@@ -839,6 +839,7 @@ struct perf_event { ...@@ -839,6 +839,7 @@ struct perf_event {
u64 id; u64 id;
perf_overflow_handler_t overflow_handler; perf_overflow_handler_t overflow_handler;
void *overflow_handler_context;
#ifdef CONFIG_EVENT_TRACING #ifdef CONFIG_EVENT_TRACING
struct ftrace_event_call *tp_event; struct ftrace_event_call *tp_event;
...@@ -960,7 +961,8 @@ extern struct perf_event * ...@@ -960,7 +961,8 @@ extern struct perf_event *
perf_event_create_kernel_counter(struct perf_event_attr *attr, perf_event_create_kernel_counter(struct perf_event_attr *attr,
int cpu, int cpu,
struct task_struct *task, struct task_struct *task,
perf_overflow_handler_t callback); perf_overflow_handler_t callback,
void *context);
extern u64 perf_event_read_value(struct perf_event *event, extern u64 perf_event_read_value(struct perf_event *event,
u64 *enabled, u64 *running); u64 *enabled, u64 *running);
......
...@@ -5745,7 +5745,8 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, ...@@ -5745,7 +5745,8 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
struct task_struct *task, struct task_struct *task,
struct perf_event *group_leader, struct perf_event *group_leader,
struct perf_event *parent_event, struct perf_event *parent_event,
perf_overflow_handler_t overflow_handler) perf_overflow_handler_t overflow_handler,
void *context)
{ {
struct pmu *pmu; struct pmu *pmu;
struct perf_event *event; struct perf_event *event;
...@@ -5803,10 +5804,13 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, ...@@ -5803,10 +5804,13 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
#endif #endif
} }
if (!overflow_handler && parent_event) if (!overflow_handler && parent_event) {
overflow_handler = parent_event->overflow_handler; overflow_handler = parent_event->overflow_handler;
context = parent_event->overflow_handler_context;
}
event->overflow_handler = overflow_handler; event->overflow_handler = overflow_handler;
event->overflow_handler_context = context;
if (attr->disabled) if (attr->disabled)
event->state = PERF_EVENT_STATE_OFF; event->state = PERF_EVENT_STATE_OFF;
...@@ -6073,7 +6077,8 @@ SYSCALL_DEFINE5(perf_event_open, ...@@ -6073,7 +6077,8 @@ SYSCALL_DEFINE5(perf_event_open,
} }
} }
event = perf_event_alloc(&attr, cpu, task, group_leader, NULL, NULL); event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
NULL, NULL);
if (IS_ERR(event)) { if (IS_ERR(event)) {
err = PTR_ERR(event); err = PTR_ERR(event);
goto err_task; goto err_task;
...@@ -6258,7 +6263,8 @@ SYSCALL_DEFINE5(perf_event_open, ...@@ -6258,7 +6263,8 @@ SYSCALL_DEFINE5(perf_event_open,
struct perf_event * struct perf_event *
perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
struct task_struct *task, struct task_struct *task,
perf_overflow_handler_t overflow_handler) perf_overflow_handler_t overflow_handler,
void *context)
{ {
struct perf_event_context *ctx; struct perf_event_context *ctx;
struct perf_event *event; struct perf_event *event;
...@@ -6268,7 +6274,8 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, ...@@ -6268,7 +6274,8 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
* Get the target context (task or percpu): * Get the target context (task or percpu):
*/ */
event = perf_event_alloc(attr, cpu, task, NULL, NULL, overflow_handler); event = perf_event_alloc(attr, cpu, task, NULL, NULL,
overflow_handler, context);
if (IS_ERR(event)) { if (IS_ERR(event)) {
err = PTR_ERR(event); err = PTR_ERR(event);
goto err; goto err;
...@@ -6552,7 +6559,7 @@ inherit_event(struct perf_event *parent_event, ...@@ -6552,7 +6559,7 @@ inherit_event(struct perf_event *parent_event,
parent_event->cpu, parent_event->cpu,
child, child,
group_leader, parent_event, group_leader, parent_event,
NULL); NULL, NULL);
if (IS_ERR(child_event)) if (IS_ERR(child_event))
return child_event; return child_event;
get_ctx(child_ctx); get_ctx(child_ctx);
...@@ -6579,6 +6586,8 @@ inherit_event(struct perf_event *parent_event, ...@@ -6579,6 +6586,8 @@ inherit_event(struct perf_event *parent_event,
child_event->ctx = child_ctx; child_event->ctx = child_ctx;
child_event->overflow_handler = parent_event->overflow_handler; child_event->overflow_handler = parent_event->overflow_handler;
child_event->overflow_handler_context
= parent_event->overflow_handler_context;
/* /*
* Precalculate sample_data sizes * Precalculate sample_data sizes
......
...@@ -431,9 +431,11 @@ int register_perf_hw_breakpoint(struct perf_event *bp) ...@@ -431,9 +431,11 @@ int register_perf_hw_breakpoint(struct perf_event *bp)
struct perf_event * struct perf_event *
register_user_hw_breakpoint(struct perf_event_attr *attr, register_user_hw_breakpoint(struct perf_event_attr *attr,
perf_overflow_handler_t triggered, perf_overflow_handler_t triggered,
void *context,
struct task_struct *tsk) struct task_struct *tsk)
{ {
return perf_event_create_kernel_counter(attr, -1, tsk, triggered); return perf_event_create_kernel_counter(attr, -1, tsk, triggered,
context);
} }
EXPORT_SYMBOL_GPL(register_user_hw_breakpoint); EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
...@@ -502,7 +504,8 @@ EXPORT_SYMBOL_GPL(unregister_hw_breakpoint); ...@@ -502,7 +504,8 @@ EXPORT_SYMBOL_GPL(unregister_hw_breakpoint);
*/ */
struct perf_event * __percpu * struct perf_event * __percpu *
register_wide_hw_breakpoint(struct perf_event_attr *attr, register_wide_hw_breakpoint(struct perf_event_attr *attr,
perf_overflow_handler_t triggered) perf_overflow_handler_t triggered,
void *context)
{ {
struct perf_event * __percpu *cpu_events, **pevent, *bp; struct perf_event * __percpu *cpu_events, **pevent, *bp;
long err; long err;
...@@ -515,7 +518,8 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr, ...@@ -515,7 +518,8 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr,
get_online_cpus(); get_online_cpus();
for_each_online_cpu(cpu) { for_each_online_cpu(cpu) {
pevent = per_cpu_ptr(cpu_events, cpu); pevent = per_cpu_ptr(cpu_events, cpu);
bp = perf_event_create_kernel_counter(attr, cpu, NULL, triggered); bp = perf_event_create_kernel_counter(attr, cpu, NULL,
triggered, context);
*pevent = bp; *pevent = bp;
......
...@@ -375,7 +375,7 @@ static int watchdog_nmi_enable(int cpu) ...@@ -375,7 +375,7 @@ static int watchdog_nmi_enable(int cpu)
hw_nmi_watchdog_set_attr(wd_attr); hw_nmi_watchdog_set_attr(wd_attr);
/* Try to register using hardware perf events */ /* Try to register using hardware perf events */
event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback); event = perf_event_create_kernel_counter(wd_attr, cpu, NULL, watchdog_overflow_callback, NULL);
if (!IS_ERR(event)) { if (!IS_ERR(event)) {
printk(KERN_INFO "NMI watchdog enabled, takes one hw-pmu counter.\n"); printk(KERN_INFO "NMI watchdog enabled, takes one hw-pmu counter.\n");
goto out_save; goto out_save;
......
...@@ -60,7 +60,7 @@ static int __init hw_break_module_init(void) ...@@ -60,7 +60,7 @@ static int __init hw_break_module_init(void)
attr.bp_len = HW_BREAKPOINT_LEN_4; attr.bp_len = HW_BREAKPOINT_LEN_4;
attr.bp_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R; attr.bp_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R;
sample_hbp = register_wide_hw_breakpoint(&attr, sample_hbp_handler); sample_hbp = register_wide_hw_breakpoint(&attr, sample_hbp_handler, NULL);
if (IS_ERR((void __force *)sample_hbp)) { if (IS_ERR((void __force *)sample_hbp)) {
ret = PTR_ERR((void __force *)sample_hbp); ret = PTR_ERR((void __force *)sample_hbp);
goto fail; goto fail;
......
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