From 9a0f05cb36888550d1509d60aa55788615abea44 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 21 Nov 2011 15:13:29 +0100 Subject: perf: Update the mmap control page on mmap() Apparently we didn't update the mmap control page right after mmap(), which leads to surprises when userspace wants to use it. Signed-off-by: Peter Zijlstra Cc: Stephane Eranian Cc: Arun Sharma Link: http://lkml.kernel.org/n/tip-dcpi7164djsexmx6ya7lilrc@git.kernel.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/events') diff --git a/kernel/events/core.c b/kernel/events/core.c index 2f8f3f1..0ca1f64 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3534,6 +3534,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) event->mmap_user = get_current_user(); vma->vm_mm->pinned_vm += event->mmap_locked; + perf_event_update_userpage(event); + unlock: if (!ret) atomic_inc(&event->mmap_count); -- cgit v1.1 From 35edc2a5095efb189e60dc32bbb9d2663aec6d24 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Sun, 20 Nov 2011 20:36:02 +0100 Subject: perf, arch: Rework perf_event_index() Put the logic to compute the event index into a per pmu method. This is required because the x86 rules are weird and wonderful and don't match the capabilities of the current scheme. AFAIK only powerpc actually has a usable userspace read of the PMCs but I'm not at all sure anybody actually used that. ARM is restored to the default since it currently does not support userspace access at all. And all software events are provided with a method that reports their index as 0 (disabled). Signed-off-by: Peter Zijlstra Cc: Michael Cree Cc: Will Deacon Cc: Deng-Cheng Zhu Cc: Anton Blanchard Cc: Eric B Munson Cc: Heiko Carstens Cc: Paul Mundt Cc: David S. Miller Cc: Richard Kuo Cc: Stephane Eranian Cc: Arun Sharma Link: http://lkml.kernel.org/n/tip-dfydxodki16lylkt3gl2j7cw@git.kernel.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 27 ++++++++++++++++++++++----- kernel/events/hw_breakpoint.c | 7 +++++++ 2 files changed, 29 insertions(+), 5 deletions(-) (limited to 'kernel/events') diff --git a/kernel/events/core.c b/kernel/events/core.c index 0ca1f64..3894309 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3208,10 +3208,6 @@ int perf_event_task_disable(void) return 0; } -#ifndef PERF_EVENT_INDEX_OFFSET -# define PERF_EVENT_INDEX_OFFSET 0 -#endif - static int perf_event_index(struct perf_event *event) { if (event->hw.state & PERF_HES_STOPPED) @@ -3220,7 +3216,7 @@ static int perf_event_index(struct perf_event *event) if (event->state != PERF_EVENT_STATE_ACTIVE) return 0; - return event->hw.idx + 1 - PERF_EVENT_INDEX_OFFSET; + return event->pmu->event_idx(event); } static void calc_timer_values(struct perf_event *event, @@ -4992,6 +4988,11 @@ static int perf_swevent_init(struct perf_event *event) return 0; } +static int perf_swevent_event_idx(struct perf_event *event) +{ + return 0; +} + static struct pmu perf_swevent = { .task_ctx_nr = perf_sw_context, @@ -5001,6 +5002,8 @@ static struct pmu perf_swevent = { .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, + + .event_idx = perf_swevent_event_idx, }; #ifdef CONFIG_EVENT_TRACING @@ -5087,6 +5090,8 @@ static struct pmu perf_tracepoint = { .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, + + .event_idx = perf_swevent_event_idx, }; static inline void perf_tp_register(void) @@ -5306,6 +5311,8 @@ static struct pmu perf_cpu_clock = { .start = cpu_clock_event_start, .stop = cpu_clock_event_stop, .read = cpu_clock_event_read, + + .event_idx = perf_swevent_event_idx, }; /* @@ -5378,6 +5385,8 @@ static struct pmu perf_task_clock = { .start = task_clock_event_start, .stop = task_clock_event_stop, .read = task_clock_event_read, + + .event_idx = perf_swevent_event_idx, }; static void perf_pmu_nop_void(struct pmu *pmu) @@ -5405,6 +5414,11 @@ static void perf_pmu_cancel_txn(struct pmu *pmu) perf_pmu_enable(pmu); } +static int perf_event_idx_default(struct perf_event *event) +{ + return event->hw.idx + 1; +} + /* * Ensures all contexts with the same task_ctx_nr have the same * pmu_cpu_context too. @@ -5594,6 +5608,9 @@ got_cpu_context: pmu->pmu_disable = perf_pmu_nop_void; } + if (!pmu->event_idx) + pmu->event_idx = perf_event_idx_default; + list_add_rcu(&pmu->entry, &pmus); ret = 0; unlock: diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index b7971d6..b0309f7 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -613,6 +613,11 @@ static void hw_breakpoint_stop(struct perf_event *bp, int flags) bp->hw.state = PERF_HES_STOPPED; } +static int hw_breakpoint_event_idx(struct perf_event *bp) +{ + return 0; +} + static struct pmu perf_breakpoint = { .task_ctx_nr = perf_sw_context, /* could eventually get its own */ @@ -622,6 +627,8 @@ static struct pmu perf_breakpoint = { .start = hw_breakpoint_start, .stop = hw_breakpoint_stop, .read = hw_breakpoint_pmu_read, + + .event_idx = hw_breakpoint_event_idx, }; int __init init_hw_breakpoint(void) -- cgit v1.1 From 365a4038486b57bb2bd516706a80f82f250f5306 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 21 Nov 2011 20:58:59 +0100 Subject: perf: Fix mmap_page::offset computation There's multiple reason the counter might be unavailable, change the condition to !->index since perf_event_index() should return 0 for all those cases. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-1ixr3olci40w8rgv2evv2ldh@git.kernel.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/events') diff --git a/kernel/events/core.c b/kernel/events/core.c index 3894309..05affc3 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3268,7 +3268,7 @@ void perf_event_update_userpage(struct perf_event *event) barrier(); userpg->index = perf_event_index(event); userpg->offset = perf_event_count(event); - if (event->state == PERF_EVENT_STATE_ACTIVE) + if (userpg->index) userpg->offset -= local64_read(&event->hw.prev_count); userpg->time_enabled = enabled + -- cgit v1.1 From 0c9d42ed4cee2aa1dfc3a260b741baae8615744f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Sun, 20 Nov 2011 23:30:47 +0100 Subject: perf, x86: Provide means for disabling userspace RDPMC Allow the disabling of RDPMC via a pmu specific attribute: echo 0 > /sys/bus/event_source/devices/cpu/rdpmc Signed-off-by: Peter Zijlstra Cc: Stephane Eranian Cc: Arun Sharma Link: http://lkml.kernel.org/n/tip-pqeog465zo5hsimtkfz73f27@git.kernel.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/events') diff --git a/kernel/events/core.c b/kernel/events/core.c index 05affc3..dcd4049e 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5505,6 +5505,7 @@ static int pmu_dev_alloc(struct pmu *pmu) if (!pmu->dev) goto out; + pmu->dev->groups = pmu->attr_groups; device_initialize(pmu->dev); ret = dev_set_name(pmu->dev, "%s", pmu->name); if (ret) -- cgit v1.1 From e3f3541c19c89a4daae39300defba68943301949 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 21 Nov 2011 11:43:53 +0100 Subject: perf: Extend the mmap control page with time (TSC) fields Extend the mmap control page with fields so that userspace can compute time deltas relative to the provided time fields. Currently only implemented for x86 with constant and nonstop TSC. Signed-off-by: Peter Zijlstra Cc: Stephane Eranian Cc: Arun Sharma Link: http://lkml.kernel.org/n/tip-3u1jucza77j3wuvs0x2bic0f@git.kernel.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) (limited to 'kernel/events') diff --git a/kernel/events/core.c b/kernel/events/core.c index dcd4049e..3a9c7d8 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3220,17 +3220,22 @@ static int perf_event_index(struct perf_event *event) } static void calc_timer_values(struct perf_event *event, + u64 *now, u64 *enabled, u64 *running) { - u64 now, ctx_time; + u64 ctx_time; - now = perf_clock(); - ctx_time = event->shadow_ctx_time + now; + *now = perf_clock(); + ctx_time = event->shadow_ctx_time + *now; *enabled = ctx_time - event->tstamp_enabled; *running = ctx_time - event->tstamp_running; } +void __weak perf_update_user_clock(struct perf_event_mmap_page *userpg, u64 now) +{ +} + /* * Callers need to ensure there can be no nesting of this function, otherwise * the seqlock logic goes bad. We can not serialize this because the arch @@ -3240,7 +3245,7 @@ void perf_event_update_userpage(struct perf_event *event) { struct perf_event_mmap_page *userpg; struct ring_buffer *rb; - u64 enabled, running; + u64 enabled, running, now; rcu_read_lock(); /* @@ -3252,7 +3257,7 @@ void perf_event_update_userpage(struct perf_event *event) * because of locking issue as we can be called in * NMI context */ - calc_timer_values(event, &enabled, &running); + calc_timer_values(event, &now, &enabled, &running); rb = rcu_dereference(event->rb); if (!rb) goto unlock; @@ -3277,6 +3282,8 @@ void perf_event_update_userpage(struct perf_event *event) userpg->time_running = running + atomic64_read(&event->child_total_time_running); + perf_update_user_clock(userpg, now); + barrier(); ++userpg->lock; preempt_enable(); @@ -3763,7 +3770,7 @@ static void perf_output_read_group(struct perf_output_handle *handle, static void perf_output_read(struct perf_output_handle *handle, struct perf_event *event) { - u64 enabled = 0, running = 0; + u64 enabled = 0, running = 0, now; u64 read_format = event->attr.read_format; /* @@ -3776,7 +3783,7 @@ static void perf_output_read(struct perf_output_handle *handle, * NMI context */ if (read_format & PERF_FORMAT_TOTAL_TIMES) - calc_timer_values(event, &enabled, &running); + calc_timer_values(event, &now, &enabled, &running); if (event->attr.read_format & PERF_FORMAT_GROUP) perf_output_read_group(handle, event, enabled, running); -- cgit v1.1