OpenCloudOS-Kernel/kernel/trace
Juri Lelli 52d85d7630 ftrace: Fix stddev calculation in function profiler
When FUNCTION_GRAPH_TRACER is enabled, ftrace can profile kernel functions
and print basic statistics about them. Unfortunately, running stddev
calculation is wrong. This patch corrects it implementing Welford’s method:

        s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) .
Link: http://lkml.kernel.org/r/1371031398-24048-1-git-send-email-juri.lelli@gmail.com

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-06-19 23:32:09 -04:00
..
Kconfig ring-buffer: Select IRQ_WORK 2013-05-03 19:24:17 -04:00
Makefile trace: Stop compiling in trace_clock unconditionally 2012-09-13 22:52:08 -04:00
blktrace.c Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block 2013-05-08 11:51:05 -07:00
ftrace.c ftrace: Fix stddev calculation in function profiler 2013-06-19 23:32:09 -04:00
power-traces.c PM / tracing: remove deprecated power trace API 2013-01-26 00:39:12 +01:00
ring_buffer.c ring-buffer: Do not poll non allocated cpu buffers 2013-05-28 10:53:20 -04:00
ring_buffer_benchmark.c tracing: Use NUMA allocation for per-cpu ring buffer pages 2011-06-14 22:04:39 -04:00
rpm-traces.c PM / Runtime: Introduce trace points for tracing rpm_* functions 2011-09-27 22:53:27 +02:00
trace.c tracing: Disable tracing on warning 2013-06-19 23:32:07 -04:00
trace.h Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-04-30 07:41:01 -07:00
trace_branch.c tracing: Fix the branch tracer that broke with buffer change 2013-03-15 00:35:54 -04:00
trace_clock.c tracing: Add "uptime" trace clock that uses jiffies 2013-03-15 00:36:09 -04:00
trace_entries.h tracing: Add trace_puts() for even faster trace_printk() tracing 2013-03-15 00:35:55 -04:00
trace_event_perf.c perf/core improvements and fixes: 2012-08-21 11:27:00 +02:00
trace_events.c tracing: Do not call kmem_cache_free() on allocation failure 2013-06-11 18:38:52 -04:00
trace_events_filter.c tracing: Add binary '&' filter for events 2013-06-19 23:30:40 -04:00
trace_events_filter_test.h tracing/filter: Add startup tests for events filter 2011-08-19 14:35:59 -04:00
trace_export.c tracing: Fix some section mismatch warnings 2013-03-15 00:34:54 -04:00
trace_functions.c tracing: Add function probe to trigger a ftrace dump of current CPU trace 2013-06-11 18:38:48 -04:00
trace_functions_graph.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_irqsoff.c tracing: Add function-trace option to disable function tracing of latency tracers 2013-03-15 00:36:08 -04:00
trace_kdb.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_kprobe.c tracing/kprobes: Remove unnecessary checking of trace_probe_is_enabled 2013-06-19 23:32:08 -04:00
trace_mmiotrace.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_nop.c tracing/ftrace: make nop-tracer use polling wait for events on pipe 2009-03-23 09:22:15 +01:00
trace_output.c Tracing updates for Linux 3.10 2013-04-29 13:55:38 -07:00
trace_output.h tracing: Rename trace_event_mutex to trace_event_sem 2013-03-15 13:22:10 -04:00
trace_printk.c tracing: Add percpu buffers for trace_printk() 2012-04-23 21:15:55 -04:00
trace_probe.c tracing: Replace strict_strto* with kstrto* 2012-10-31 16:45:23 -04:00
trace_probe.h uprobes/tracing: Introduce is_trace_uprobe_enabled() 2013-02-08 18:24:30 +01:00
trace_sched_switch.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_sched_wakeup.c tracing: Add function-trace option to disable function tracing of latency tracers 2013-03-15 00:36:08 -04:00
trace_selftest.c tracing: Fix bad parameter passed in branch selftest 2013-05-29 16:00:03 -04:00
trace_selftest_dynamic.c ftrace: Add self-tests for multiple function trace users 2011-05-18 19:24:51 -04:00
trace_stack.c Tracing updates for Linux 3.10 2013-04-29 13:55:38 -07:00
trace_stat.c tracing: Check return value of tracing_init_dentry() 2013-04-12 23:02:32 -04:00
trace_stat.h tracing/stat: Add stat_release() callback 2009-07-10 12:14:05 +02:00
trace_syscalls.c tracing: Fix comment about prefix in arch_syscall_match_sym_name() 2013-03-15 13:22:09 -04:00
trace_uprobe.c uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is empty 2013-04-15 17:39:52 +02:00