From ed0449af5373abd766c79fbf83254bebc996bd23 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 1 Nov 2011 09:09:35 +0800 Subject: tracing: Restore system filter behavior Though not all events have field 'prev_pid', it was allowed to do this: # echo 'prev_pid == 100' > events/sched/filter but commit 75b8e98263fdb0bfbdeba60d4db463259f1fe8a2 (tracing/filter: Swap entire filter of events) broke it without any reason. Link: http://lkml.kernel.org/r/4EAF46CF.8040408@cn.fujitsu.com Signed-off-by: Li Zefan Signed-off-by: Steven Rostedt --- include/linux/ftrace_event.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 96efa6794ea5..c3da42dd22ba 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -172,6 +172,7 @@ enum { TRACE_EVENT_FL_FILTERED_BIT, TRACE_EVENT_FL_RECORDED_CMD_BIT, TRACE_EVENT_FL_CAP_ANY_BIT, + TRACE_EVENT_FL_NO_SET_FILTER_BIT, }; enum { @@ -179,6 +180,7 @@ enum { TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT), TRACE_EVENT_FL_RECORDED_CMD = (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT), TRACE_EVENT_FL_CAP_ANY = (1 << TRACE_EVENT_FL_CAP_ANY_BIT), + TRACE_EVENT_FL_NO_SET_FILTER = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT), }; struct ftrace_event_call { -- cgit v1.2.3 From 0f5a2601284237e2ba089389fd75d67f77626cef Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 16 Nov 2011 14:38:16 +0100 Subject: perf: Avoid a useless pmu_disable() in the perf-tick Gleb writes: > Currently pmu is disabled and re-enabled on each timer interrupt even > when no rotation or frequency adjustment is needed. On Intel CPU this > results in two writes into PERF_GLOBAL_CTRL MSR per tick. On bare metal > it does not cause significant slowdown, but when running perf in a virtual > machine it leads to 20% slowdown on my machine. Cure this by keeping a perf_event_context::nr_freq counter that counts the number of active events that require frequency adjustments and use this in a similar fashion to the already existing nr_events != nr_active test in perf_rotate_context(). By being able to exclude both rotation and frequency adjustments a-priory for the common case we can avoid the otherwise superfluous PMU disable. Suggested-by: Gleb Natapov Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-515yhoatehd3gza7we9fapaa@git.kernel.org Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index b1f89122bf6a..cb44c9e75660 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -890,6 +890,7 @@ struct perf_event_context { int nr_active; int is_active; int nr_stat; + int nr_freq; int rotate_disable; atomic_t refcount; struct task_struct *task; -- cgit v1.2.3 From 1e2ad28f80b4e155678259238f51edebc19e4014 Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Fri, 18 Nov 2011 12:35:21 +0100 Subject: perf, x86: Implement event scheduler helper functions This patch introduces x86 perf scheduler code helper functions. We need this to later add more complex functionality to support overlapping counter constraints (next patch). The algorithm is modified so that the range of weight values is now generated from the constraints. There shouldn't be other functional changes. With the helper functions the scheduler is controlled. There are functions to initialize, traverse the event list, find unused counters etc. The scheduler keeps its own state. V3: * Added macro for_each_set_bit_cont(). * Changed functions interfaces of perf_sched_find_counter() and perf_sched_next_event() to use bool as return value. * Added some comments to make code better understandable. V4: * Fix broken event assignment if weight of the first event is not wmin (perf_sched_init()). Signed-off-by: Robert Richter Signed-off-by: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1321616122-1533-2-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar --- include/linux/bitops.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/bitops.h b/include/linux/bitops.h index a3ef66a2a083..3c1063acb2ab 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -22,8 +22,14 @@ extern unsigned long __sw_hweight64(__u64 w); #include #define for_each_set_bit(bit, addr, size) \ - for ((bit) = find_first_bit((addr), (size)); \ - (bit) < (size); \ + for ((bit) = find_first_bit((addr), (size)); \ + (bit) < (size); \ + (bit) = find_next_bit((addr), (size), (bit) + 1)) + +/* same as for_each_set_bit() but use bit as value to start with */ +#define for_each_set_bit_cont(bit, addr, size) \ + for ((bit) = find_next_bit((addr), (size), (bit)); \ + (bit) < (size); \ (bit) = find_next_bit((addr), (size), (bit) + 1)) static __inline__ int get_bitmask_order(unsigned int count) -- cgit v1.2.3 From b202952075f62603bea9bfb6ebc6b0420db11949 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Sun, 27 Nov 2011 17:59:09 +0200 Subject: perf, core: Rate limit perf_sched_events jump_label patching jump_lable patching is very expensive operation that involves pausing all cpus. The patching of perf_sched_events jump_label is easily controllable from userspace by unprivileged user. When te user runs a loop like this: "while true; do perf stat -e cycles true; done" ... the performance of my test application that just increments a counter for one second drops by 4%. This is on a 16 cpu box with my test application using only one of them. An impact on a real server doing real work will be worse. Performance of KVM PMU drops nearly 50% due to jump_lable for "perf record" since KVM PMU implementation creates and destroys perf event frequently. This patch introduces a way to rate limit jump_label patching and uses it to fix the above problem. I believe that as jump_label use will spread the problem will become more common and thus solving it in a generic code is appropriate. Also fixing it in the perf code would result in moving jump_label accounting logic to perf code with all the ifdefs in case of JUMP_LABEL=n kernel. With this patch all details are nicely hidden inside jump_label code. Signed-off-by: Gleb Natapov Acked-by: Jason Baron Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20111127155909.GO2557@redhat.com Signed-off-by: Ingo Molnar --- include/linux/jump_label.h | 24 ++++++++++++++++++++++++ include/linux/perf_event.h | 6 +++--- 2 files changed, 27 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 388b0d425b50..a1e7f909c801 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -3,6 +3,7 @@ #include #include +#include #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) @@ -14,6 +15,12 @@ struct jump_label_key { #endif }; +struct jump_label_key_deferred { + struct jump_label_key key; + unsigned long timeout; + struct delayed_work work; +}; + # include # define HAVE_JUMP_LABEL #endif /* CC_HAVE_ASM_GOTO && CONFIG_JUMP_LABEL */ @@ -51,8 +58,11 @@ extern void arch_jump_label_transform_static(struct jump_entry *entry, extern int jump_label_text_reserved(void *start, void *end); extern void jump_label_inc(struct jump_label_key *key); extern void jump_label_dec(struct jump_label_key *key); +extern void jump_label_dec_deferred(struct jump_label_key_deferred *key); extern bool jump_label_enabled(struct jump_label_key *key); extern void jump_label_apply_nops(struct module *mod); +extern void jump_label_rate_limit(struct jump_label_key_deferred *key, + unsigned long rl); #else /* !HAVE_JUMP_LABEL */ @@ -68,6 +78,10 @@ static __always_inline void jump_label_init(void) { } +struct jump_label_key_deferred { + struct jump_label_key key; +}; + static __always_inline bool static_branch(struct jump_label_key *key) { if (unlikely(atomic_read(&key->enabled))) @@ -85,6 +99,11 @@ static inline void jump_label_dec(struct jump_label_key *key) atomic_dec(&key->enabled); } +static inline void jump_label_dec_deferred(struct jump_label_key_deferred *key) +{ + jump_label_dec(&key->key); +} + static inline int jump_label_text_reserved(void *start, void *end) { return 0; @@ -102,6 +121,11 @@ static inline int jump_label_apply_nops(struct module *mod) { return 0; } + +static inline void jump_label_rate_limit(struct jump_label_key_deferred *key, + unsigned long rl) +{ +} #endif /* HAVE_JUMP_LABEL */ #endif /* _LINUX_JUMP_LABEL_H */ diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index cb44c9e75660..564769cdb473 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1064,12 +1064,12 @@ perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr) } } -extern struct jump_label_key perf_sched_events; +extern struct jump_label_key_deferred perf_sched_events; static inline void perf_event_task_sched_in(struct task_struct *prev, struct task_struct *task) { - if (static_branch(&perf_sched_events)) + if (static_branch(&perf_sched_events.key)) __perf_event_task_sched_in(prev, task); } @@ -1078,7 +1078,7 @@ static inline void perf_event_task_sched_out(struct task_struct *prev, { perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, NULL, 0); - if (static_branch(&perf_sched_events)) + if (static_branch(&perf_sched_events.key)) __perf_event_task_sched_out(prev, next); } -- cgit v1.2.3 From ac99b862fb98a36929831791da31714f709c2aa8 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 6 Jul 2011 14:20:14 +0200 Subject: jump_label: Provide jump_label_key initializers Provide two initializers for jump_label_key that initialize it enabled or disabled. Also modify all jump_label code to allow for jump_labels to be initialized enabled. Signed-off-by: Peter Zijlstra Cc: Jason Baron Link: http://lkml.kernel.org/n/tip-p40e3yj21b68y03z1yv825e7@git.kernel.org Signed-off-by: Ingo Molnar --- include/linux/jump_label.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index a1e7f909c801..5ce8b140428f 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -128,4 +128,7 @@ static inline void jump_label_rate_limit(struct jump_label_key_deferred *key, } #endif /* HAVE_JUMP_LABEL */ +#define jump_label_key_enabled ((struct jump_label_key){ .enabled = ATOMIC_INIT(1), }) +#define jump_label_key_disabled ((struct jump_label_key){ .enabled = ATOMIC_INIT(0), }) + #endif /* _LINUX_JUMP_LABEL_H */ -- cgit v1.2.3 From c37e17497e01fc0f5d2d6feb5723b210b3ab8890 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Sun, 11 Dec 2011 00:28:52 +0100 Subject: perf events: Add PERF_COUNT_HW_REF_CPU_CYCLES generic PMU event This event counts the number of reference core cpu cycles. Reference means that the event increments at a constant rate which is not subject to core CPU frequency adjustments. The event may not count when the processor is in halted (low power) state. As such, it may not be equivalent to wall clock time. However, when the processor is not halted state, the event keeps a constant correlation with wall clock time. Signed-off-by: Stephane Eranian Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1323559734-3488-3-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 564769cdb473..08855613ceb3 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -54,6 +54,7 @@ enum perf_hw_id { PERF_COUNT_HW_BUS_CYCLES = 6, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND = 7, PERF_COUNT_HW_STALLED_CYCLES_BACKEND = 8, + PERF_COUNT_HW_REF_CPU_CYCLES = 9, PERF_COUNT_HW_MAX, /* non-ABI */ }; -- cgit v1.2.3