From c48b60538c3ba05a7a2713c4791b25405525431b Mon Sep 17 00:00:00 2001 From: Vince Weaver Date: Thu, 1 Mar 2012 17:28:14 -0500 Subject: perf/x86: Use rdpmc() rather than rdmsr() when possible in the kernel The rdpmc instruction is faster than the equivelant rdmsr call, so use it when possible in the kernel. The perfctr kernel patches did this, after extensive testing showed rdpmc to always be faster (One can look in etc/costs in the perfctr-2.6 package to see a historical list of the overhead). I have done some tests on a 3.2 kernel, the kernel module I used was included in the first posting of this patch: rdmsr rdpmc Core2 T9900: 203.9 cycles 30.9 cycles AMD fam0fh: 56.2 cycles 9.8 cycles Atom 6/28/2: 129.7 cycles 50.6 cycles The speedup of using rdpmc is large. [ It's probably possible (and desirable) to do this without requiring a new field in the hw_perf_event structure, but the fixed events make this tricky. ] Signed-off-by: Vince Weaver Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1203011724030.26934@cl320.eecs.utk.edu Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/perf_event.h') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 45db49f64bb4..1ce887abcc5c 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -677,6 +677,7 @@ struct hw_perf_event { u64 last_tag; unsigned long config_base; unsigned long event_base; + int event_base_rdpmc; int idx; int last_cpu; -- cgit v1.2.3 From 0cda4c023132aa93f2dd94811061f812e88daf4c Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Fri, 15 Jun 2012 14:31:33 +0800 Subject: perf: Introduce perf_pmu_migrate_context() Originally from Peter Zijlstra. The helper migrates perf events from one cpu to another cpu. Signed-off-by: Zheng Yan Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1339741902-8449-5-git-send-email-zheng.z.yan@intel.com Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/perf_event.h') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 1ce887abcc5c..76c5c8b724a7 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1107,6 +1107,8 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, struct task_struct *task, perf_overflow_handler_t callback, void *context); +extern void perf_pmu_migrate_context(struct pmu *pmu, + int src_cpu, int dst_cpu); extern u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running); -- cgit v1.2.3 From e6dab5ffab59e910ec0e3355f4a6f29f7a7be474 Mon Sep 17 00:00:00 2001 From: Andrew Vagin Date: Wed, 11 Jul 2012 18:14:58 +0400 Subject: perf/trace: Add ability to set a target task for events A few events are interesting not only for a current task. For example, sched_stat_* events are interesting for a task which wakes up. For this reason, it will be good if such events will be delivered to a target task too. Now a target task can be set by using __perf_task(). The original idea and a draft patch belongs to Peter Zijlstra. I need these events for profiling sleep times. sched_switch is used for getting callchains and sched_stat_* is used for getting time periods. These events are combined in user space, then it can be analyzed by perf tools. Inspired-by: Peter Zijlstra Cc: Steven Rostedt Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Steven Rostedt Cc: Arun Sharma Signed-off-by: Andrew Vagin Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1342016098-213063-1-git-send-email-avagin@openvz.org Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/perf_event.h') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 76c5c8b724a7..7602ccb3f40e 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1272,7 +1272,8 @@ static inline bool perf_paranoid_kernel(void) extern void perf_event_init(void); extern void perf_tp_event(u64 addr, u64 count, void *record, int entry_size, struct pt_regs *regs, - struct hlist_head *head, int rctx); + struct hlist_head *head, int rctx, + struct task_struct *task); extern void perf_bp_event(struct perf_event *event, void *data); #ifndef perf_misc_flags -- cgit v1.2.3