From 404ff638403e9286691b9b1f86d514c1d7737e8f Mon Sep 17 00:00:00 2001 From: Deng-Cheng Zhu Date: Fri, 21 Jan 2011 16:19:18 +0800 Subject: MIPS, Perf-events: Work with the new PMU interface This is the MIPS part of the following commits by Peter Zijlstra: - a4eaf7f14675cb512d69f0c928055e73d0c6d252 perf: Rework the PMU methods Replace pmu::{enable,disable,start,stop,unthrottle} with pmu::{add,del,start,stop}, all of which take a flags argument. The new interface extends the capability to stop a counter while keeping it scheduled on the PMU. We replace the throttled state with the generic stopped state. This also allows us to efficiently stop/start counters over certain code paths (like IRQ handlers). It also allows scheduling a counter without it starting, allowing for a generic frozen state (useful for rotating stopped counters). The stopped state is implemented in two different ways, depending on how the architecture implemented the throttled state: 1) We disable the counter: a) the pmu has per-counter enable bits, we flip that b) we program a NOP event, preserving the counter state 2) We store the counter state and ignore all read/overflow events For MIPSXX, the stopped state is implemented in the way of 1.b as above. - 33696fc0d141bbbcb12f75b69608ea83282e3117 perf: Per PMU disable Changes perf_disable() into perf_pmu_disable(). - 24cd7f54a0d47e1d5b3de29e2456bfbd2d8447b7 perf: Reduce perf_disable() usage Since the current perf_disable() usage is only an optimization, remove it for now. This eases the removal of the __weak hw_perf_enable() interface. - b0a873ebbf87bf38bf70b5e39a7cadc96099fa13 perf: Register PMU implementations Simple registration interface for struct pmu, this provides the infrastructure for removing all the weak functions. - 51b0fe39549a04858001922919ab355dee9bdfcf perf: Deconstify struct pmu sed -ie 's/const struct pmu\>/struct pmu/g' `git grep -l "const struct pmu\>"` Reported-by: Wu Zhangjin Acked-by: David Daney Signed-off-by: Deng-Cheng Zhu To: a.p.zijlstra@chello.nl To: fweisbec@gmail.com To: will.deacon@arm.com Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: wuzhangjin@gmail.com Cc: paulus@samba.org Cc: mingo@elte.hu Cc: acme@redhat.com Cc: dengcheng.zhu@gmail.com Cc: matt@console-pimps.org Cc: sshtylyov@mvista.com Cc: ddaney@caviumnetworks.com Patchwork: http://patchwork.linux-mips.org/patch/2012/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/perf_event.c | 275 ++++++++++++++++++++++++------------------ 1 file changed, 156 insertions(+), 119 deletions(-) (limited to 'arch/mips/kernel/perf_event.c') diff --git a/arch/mips/kernel/perf_event.c b/arch/mips/kernel/perf_event.c index 2b7f3f703b83..1ee44a3f9718 100644 --- a/arch/mips/kernel/perf_event.c +++ b/arch/mips/kernel/perf_event.c @@ -161,41 +161,6 @@ mipspmu_event_set_period(struct perf_event *event, return ret; } -static int mipspmu_enable(struct perf_event *event) -{ - struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); - struct hw_perf_event *hwc = &event->hw; - int idx; - int err = 0; - - /* To look for a free counter for this event. */ - idx = mipspmu->alloc_counter(cpuc, hwc); - if (idx < 0) { - err = idx; - goto out; - } - - /* - * If there is an event in the counter we are going to use then - * make sure it is disabled. - */ - event->hw.idx = idx; - mipspmu->disable_event(idx); - cpuc->events[idx] = event; - - /* Set the period for the event. */ - mipspmu_event_set_period(event, hwc, idx); - - /* Enable the event. */ - mipspmu->enable_event(hwc, idx); - - /* Propagate our changes to the userspace mapping. */ - perf_event_update_userpage(event); - -out: - return err; -} - static void mipspmu_event_update(struct perf_event *event, struct hw_perf_event *hwc, int idx) @@ -231,32 +196,90 @@ again: return; } -static void mipspmu_disable(struct perf_event *event) +static void mipspmu_start(struct perf_event *event, int flags) +{ + struct hw_perf_event *hwc = &event->hw; + + if (!mipspmu) + return; + + if (flags & PERF_EF_RELOAD) + WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE)); + + hwc->state = 0; + + /* Set the period for the event. */ + mipspmu_event_set_period(event, hwc, hwc->idx); + + /* Enable the event. */ + mipspmu->enable_event(hwc, hwc->idx); +} + +static void mipspmu_stop(struct perf_event *event, int flags) +{ + struct hw_perf_event *hwc = &event->hw; + + if (!mipspmu) + return; + + if (!(hwc->state & PERF_HES_STOPPED)) { + /* We are working on a local event. */ + mipspmu->disable_event(hwc->idx); + barrier(); + mipspmu_event_update(event, hwc, hwc->idx); + hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE; + } +} + +static int mipspmu_add(struct perf_event *event, int flags) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); struct hw_perf_event *hwc = &event->hw; - int idx = hwc->idx; + int idx; + int err = 0; + perf_pmu_disable(event->pmu); - WARN_ON(idx < 0 || idx >= mipspmu->num_counters); + /* To look for a free counter for this event. */ + idx = mipspmu->alloc_counter(cpuc, hwc); + if (idx < 0) { + err = idx; + goto out; + } - /* We are working on a local event. */ + /* + * If there is an event in the counter we are going to use then + * make sure it is disabled. + */ + event->hw.idx = idx; mipspmu->disable_event(idx); + cpuc->events[idx] = event; - barrier(); - - mipspmu_event_update(event, hwc, idx); - cpuc->events[idx] = NULL; - clear_bit(idx, cpuc->used_mask); + hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE; + if (flags & PERF_EF_START) + mipspmu_start(event, PERF_EF_RELOAD); + /* Propagate our changes to the userspace mapping. */ perf_event_update_userpage(event); + +out: + perf_pmu_enable(event->pmu); + return err; } -static void mipspmu_unthrottle(struct perf_event *event) +static void mipspmu_del(struct perf_event *event, int flags) { + struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; - mipspmu->enable_event(hwc, hwc->idx); + WARN_ON(idx < 0 || idx >= mipspmu->num_counters); + + mipspmu_stop(event, PERF_EF_UPDATE); + cpuc->events[idx] = NULL; + clear_bit(idx, cpuc->used_mask); + + perf_event_update_userpage(event); } static void mipspmu_read(struct perf_event *event) @@ -270,12 +293,17 @@ static void mipspmu_read(struct perf_event *event) mipspmu_event_update(event, hwc, hwc->idx); } -static struct pmu pmu = { - .enable = mipspmu_enable, - .disable = mipspmu_disable, - .unthrottle = mipspmu_unthrottle, - .read = mipspmu_read, -}; +static void mipspmu_enable(struct pmu *pmu) +{ + if (mipspmu) + mipspmu->start(); +} + +static void mipspmu_disable(struct pmu *pmu) +{ + if (mipspmu) + mipspmu->stop(); +} static atomic_t active_events = ATOMIC_INIT(0); static DEFINE_MUTEX(pmu_reserve_mutex); @@ -318,6 +346,82 @@ static void mipspmu_free_irq(void) perf_irq = save_perf_irq; } +/* + * mipsxx/rm9000/loongson2 have different performance counters, they have + * specific low-level init routines. + */ +static void reset_counters(void *arg); +static int __hw_perf_event_init(struct perf_event *event); + +static void hw_perf_event_destroy(struct perf_event *event) +{ + if (atomic_dec_and_mutex_lock(&active_events, + &pmu_reserve_mutex)) { + /* + * We must not call the destroy function with interrupts + * disabled. + */ + on_each_cpu(reset_counters, + (void *)(long)mipspmu->num_counters, 1); + mipspmu_free_irq(); + mutex_unlock(&pmu_reserve_mutex); + } +} + +static int mipspmu_event_init(struct perf_event *event) +{ + int err = 0; + + switch (event->attr.type) { + case PERF_TYPE_RAW: + case PERF_TYPE_HARDWARE: + case PERF_TYPE_HW_CACHE: + break; + + default: + return -ENOENT; + } + + if (!mipspmu || event->cpu >= nr_cpumask_bits || + (event->cpu >= 0 && !cpu_online(event->cpu))) + return -ENODEV; + + if (!atomic_inc_not_zero(&active_events)) { + if (atomic_read(&active_events) > MIPS_MAX_HWEVENTS) { + atomic_dec(&active_events); + return -ENOSPC; + } + + mutex_lock(&pmu_reserve_mutex); + if (atomic_read(&active_events) == 0) + err = mipspmu_get_irq(); + + if (!err) + atomic_inc(&active_events); + mutex_unlock(&pmu_reserve_mutex); + } + + if (err) + return err; + + err = __hw_perf_event_init(event); + if (err) + hw_perf_event_destroy(event); + + return err; +} + +static struct pmu pmu = { + .pmu_enable = mipspmu_enable, + .pmu_disable = mipspmu_disable, + .event_init = mipspmu_event_init, + .add = mipspmu_add, + .del = mipspmu_del, + .start = mipspmu_start, + .stop = mipspmu_stop, + .read = mipspmu_read, +}; + static inline unsigned int mipspmu_perf_event_encode(const struct mips_perf_event *pev) { @@ -409,73 +513,6 @@ static int validate_group(struct perf_event *event) return 0; } -/* - * mipsxx/rm9000/loongson2 have different performance counters, they have - * specific low-level init routines. - */ -static void reset_counters(void *arg); -static int __hw_perf_event_init(struct perf_event *event); - -static void hw_perf_event_destroy(struct perf_event *event) -{ - if (atomic_dec_and_mutex_lock(&active_events, - &pmu_reserve_mutex)) { - /* - * We must not call the destroy function with interrupts - * disabled. - */ - on_each_cpu(reset_counters, - (void *)(long)mipspmu->num_counters, 1); - mipspmu_free_irq(); - mutex_unlock(&pmu_reserve_mutex); - } -} - -const struct pmu *hw_perf_event_init(struct perf_event *event) -{ - int err = 0; - - if (!mipspmu || event->cpu >= nr_cpumask_bits || - (event->cpu >= 0 && !cpu_online(event->cpu))) - return ERR_PTR(-ENODEV); - - if (!atomic_inc_not_zero(&active_events)) { - if (atomic_read(&active_events) > MIPS_MAX_HWEVENTS) { - atomic_dec(&active_events); - return ERR_PTR(-ENOSPC); - } - - mutex_lock(&pmu_reserve_mutex); - if (atomic_read(&active_events) == 0) - err = mipspmu_get_irq(); - - if (!err) - atomic_inc(&active_events); - mutex_unlock(&pmu_reserve_mutex); - } - - if (err) - return ERR_PTR(err); - - err = __hw_perf_event_init(event); - if (err) - hw_perf_event_destroy(event); - - return err ? ERR_PTR(err) : &pmu; -} - -void hw_perf_enable(void) -{ - if (mipspmu) - mipspmu->start(); -} - -void hw_perf_disable(void) -{ - if (mipspmu) - mipspmu->stop(); -} - /* This is needed by specific irq handlers in perf_event_*.c */ static void handle_associated_event(struct cpu_hw_events *cpuc, -- cgit v1.2.3 From c049b6a5f2d8ca16094a4f2a6d8ad39f888a551a Mon Sep 17 00:00:00 2001 From: Deng-Cheng Zhu Date: Fri, 21 Jan 2011 16:19:19 +0800 Subject: MIPS, Perf-events: Fix event check in validate_event() Ignore events that are in off/error state or belong to a different PMU. This patch originates from the following commit for ARM by Will Deacon: - 65b4711ff513767341aa1915c822de6ec0de65cb ARM: 6352/1: perf: fix event validation The validate_event function in the ARM perf events backend has the following problems: 1.) Events that are disabled count towards the cost. 2.) Events associated with other PMUs [for example, software events or breakpoints] do not count towards the cost, but do fail validation, causing the group to fail. This patch changes validate_event so that it ignores events in the PERF_EVENT_STATE_OFF state or that are scheduled for other PMUs. Acked-by: Will Deacon Acked-by: David Daney Signed-off-by: Deng-Cheng Zhu To: a.p.zijlstra@chello.nl To: fweisbec@gmail.com To: will.deacon@arm.com Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: wuzhangjin@gmail.com Cc: paulus@samba.org Cc: mingo@elte.hu Cc: acme@redhat.com Cc: dengcheng.zhu@gmail.com Cc: matt@console-pimps.org Cc: sshtylyov@mvista.com Cc: ddaney@caviumnetworks.com Patchwork: http://patchwork.linux-mips.org/patch/2013/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/perf_event.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/mips/kernel/perf_event.c') diff --git a/arch/mips/kernel/perf_event.c b/arch/mips/kernel/perf_event.c index 1ee44a3f9718..3d55761146e5 100644 --- a/arch/mips/kernel/perf_event.c +++ b/arch/mips/kernel/perf_event.c @@ -486,8 +486,9 @@ static int validate_event(struct cpu_hw_events *cpuc, { struct hw_perf_event fake_hwc = event->hw; - if (event->pmu && event->pmu != &pmu) - return 0; + /* Allow mixed event group. So return 1 to pass validation. */ + if (event->pmu != &pmu || event->state <= PERF_EVENT_STATE_OFF) + return 1; return mipspmu->alloc_counter(cpuc, &fake_hwc) >= 0; } -- cgit v1.2.3 From 98f92f2f9e2fd959157b1d52f7ae160683812740 Mon Sep 17 00:00:00 2001 From: Deng-Cheng Zhu Date: Fri, 21 Jan 2011 16:19:20 +0800 Subject: MIPS, Perf-events: Work with the new callchain interface This is the MIPS part of the following commits by Frederic Weisbecker: - f72c1a931e311bb7780fee19e41a89ac42cab50e perf: Factorize callchain context handling Store the kernel and user contexts from the generic layer instead of archs, this gathers some repetitive code. - 56962b4449af34070bb1994621ef4f0265eed4d8 perf: Generalize some arch callchain code - Most archs use one callchain buffer per cpu, except x86 that needs to deal with NMIs. Provide a default perf_callchain_buffer() implementation that x86 overrides. - Centralize all the kernel/user regs handling and invoke new arch handlers from there: perf_callchain_user() / perf_callchain_kernel() That avoid all the user_mode(), current->mm checks and so... - Invert some parameters in perf_callchain_*() helpers: entry to the left, regs to the right, following the traditional (dst, src). - 70791ce9ba68a5921c9905ef05d23f62a90bc10c perf: Generalize callchain_store() callchain_store() is the same on every archs, inline it in perf_event.h and rename it to perf_callchain_store() to avoid any collision. This removes repetitive code. - c1a65932fd7216fdc9a0db8bbffe1d47842f862c perf: Drop unappropriate tests on arch callchains Drop the TASK_RUNNING test on user tasks for callchains as this check doesn't seem to make any sense. Also remove the tests for !current that is not supposed to happen and current->pid as this should be handled at the generic level, with exclude_idle attribute. Reported-by: Wu Zhangjin Acked-by: Frederic Weisbecker Acked-by: David Daney Signed-off-by: Deng-Cheng Zhu To: a.p.zijlstra@chello.nl To: will.deacon@arm.com Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: paulus@samba.org Cc: mingo@elte.hu Cc: acme@redhat.com Cc: dengcheng.zhu@gmail.com Cc: matt@console-pimps.org Cc: sshtylyov@mvista.com Patchwork: http://patchwork.linux-mips.org/patch/2014/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/perf_event.c | 63 +++++-------------------------------------- 1 file changed, 6 insertions(+), 57 deletions(-) (limited to 'arch/mips/kernel/perf_event.c') diff --git a/arch/mips/kernel/perf_event.c b/arch/mips/kernel/perf_event.c index 3d55761146e5..8f7d2f84d095 100644 --- a/arch/mips/kernel/perf_event.c +++ b/arch/mips/kernel/perf_event.c @@ -534,21 +534,13 @@ handle_associated_event(struct cpu_hw_events *cpuc, #include "perf_event_mipsxx.c" /* Callchain handling code. */ -static inline void -callchain_store(struct perf_callchain_entry *entry, - u64 ip) -{ - if (entry->nr < PERF_MAX_STACK_DEPTH) - entry->ip[entry->nr++] = ip; -} /* * Leave userspace callchain empty for now. When we find a way to trace * the user stack callchains, we add here. */ -static void -perf_callchain_user(struct pt_regs *regs, - struct perf_callchain_entry *entry) +void perf_callchain_user(struct perf_callchain_entry *entry, + struct pt_regs *regs) { } @@ -561,23 +553,21 @@ static void save_raw_perf_callchain(struct perf_callchain_entry *entry, while (!kstack_end(sp)) { addr = *sp++; if (__kernel_text_address(addr)) { - callchain_store(entry, addr); + perf_callchain_store(entry, addr); if (entry->nr >= PERF_MAX_STACK_DEPTH) break; } } } -static void -perf_callchain_kernel(struct pt_regs *regs, - struct perf_callchain_entry *entry) +void perf_callchain_kernel(struct perf_callchain_entry *entry, + struct pt_regs *regs) { unsigned long sp = regs->regs[29]; #ifdef CONFIG_KALLSYMS unsigned long ra = regs->regs[31]; unsigned long pc = regs->cp0_epc; - callchain_store(entry, PERF_CONTEXT_KERNEL); if (raw_show_trace || !__kernel_text_address(pc)) { unsigned long stack_page = (unsigned long)task_stack_page(current); @@ -587,53 +577,12 @@ perf_callchain_kernel(struct pt_regs *regs, return; } do { - callchain_store(entry, pc); + perf_callchain_store(entry, pc); if (entry->nr >= PERF_MAX_STACK_DEPTH) break; pc = unwind_stack(current, &sp, pc, &ra); } while (pc); #else - callchain_store(entry, PERF_CONTEXT_KERNEL); save_raw_perf_callchain(entry, sp); #endif } - -static void -perf_do_callchain(struct pt_regs *regs, - struct perf_callchain_entry *entry) -{ - int is_user; - - if (!regs) - return; - - is_user = user_mode(regs); - - if (!current || !current->pid) - return; - - if (is_user && current->state != TASK_RUNNING) - return; - - if (!is_user) { - perf_callchain_kernel(regs, entry); - if (current->mm) - regs = task_pt_regs(current); - else - regs = NULL; - } - if (regs) - perf_callchain_user(regs, entry); -} - -static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry); - -struct perf_callchain_entry * -perf_callchain(struct pt_regs *regs) -{ - struct perf_callchain_entry *entry = &__get_cpu_var(pmc_irq_entry); - - entry->nr = 0; - perf_do_callchain(regs, entry); - return entry; -} -- cgit v1.2.3 From ba9786f32473410bbec256db9745a7fbcaace69f Mon Sep 17 00:00:00 2001 From: Deng-Cheng Zhu Date: Fri, 21 Jan 2011 16:19:21 +0800 Subject: MIPS, Perf-events: Use unsigned delta for right shift in event update Leverage the commit for ARM by Will Deacon: - 446a5a8b1eb91a6990e5c8fe29f14e7a95b69132 ARM: 6205/1: perf: ensure counter delta is treated as unsigned Hardware performance counters on ARM are 32-bits wide but atomic64_t variables are used to represent counter data in the hw_perf_event structure. The armpmu_event_update function right-shifts a signed 64-bit delta variable and adds the result to the event count. This can lead to shifting in sign-bits if the MSB of the 32-bit counter value is set. This results in perf output such as: Performance counter stats for 'sleep 20': 18446744073460670464 cycles <-- 0xFFFFFFFFF12A6000 7783773 instructions # 0.000 IPC 465 context-switches 161 page-faults 1172393 branches 20.154242147 seconds time elapsed This patch ensures that the delta value is treated as unsigned so that the right shift sets the upper bits to zero. Acked-by: Will Deacon Acked-by: David Daney Signed-off-by: Deng-Cheng Zhu To: a.p.zijlstra@chello.nl To: fweisbec@gmail.com To: will.deacon@arm.com Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: wuzhangjin@gmail.com Cc: paulus@samba.org Cc: mingo@elte.hu Cc: acme@redhat.com Cc: matt@console-pimps.org Cc: sshtylyov@mvista.com Patchwork: http://patchwork.linux-mips.org/patch/2015/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/perf_event.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/mips/kernel/perf_event.c') diff --git a/arch/mips/kernel/perf_event.c b/arch/mips/kernel/perf_event.c index 8f7d2f84d095..a8244854d3dc 100644 --- a/arch/mips/kernel/perf_event.c +++ b/arch/mips/kernel/perf_event.c @@ -169,7 +169,7 @@ static void mipspmu_event_update(struct perf_event *event, unsigned long flags; int shift = 64 - TOTAL_BITS; s64 prev_raw_count, new_raw_count; - s64 delta; + u64 delta; again: prev_raw_count = local64_read(&hwc->prev_count); -- cgit v1.2.3