iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
417944c4c7
linux/kernel/trace
History
Steven Rostedt (Red Hat) 417944c4c7 tracing: Add a way to soft disable trace events 
In order to let triggers enable or disable events, we need a 'soft'
method for doing so. For example, if a function probe is added that
lets a user enable or disable events when a function is called, that
change must be done without taking locks or a mutex, and definitely
it can't sleep. But the full enabling of a tracepoint is expensive.

By adding a 'SOFT_DISABLE' flag, and converting the flags to be updated
without the protection of a mutex (using set/clear_bit()), this soft
disable flag can be used to allow critical sections to enable or disable
events from being traced (after the event has been placed into "SOFT_MODE").

Some caveats though: The comm recorder (to map pids with a comm) can not
be soft disabled (yet). If you disable an event with with a "soft"
disable and wait a while before reading the trace, the comm cache may be
replaced and you'll get a bunch of <...> for comms in the trace.

Reading the "enable" file for an event that is disabled will now give
you "0*" where the '*' denotes that the tracepoint is still active but
the event itself is "disabled".

[ fixed _BIT used in & operation : thanks to Dan Carpenter and smatch ]

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-03-15 00:36:03 -04:00
..
blktrace.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
ftrace.c ftrace: Use manual free after synchronize_sched() not call_rcu_sched() 2013-03-15 00:36:03 -04:00
Kconfig tracing: Add config option to allow snapshot to swap per cpu 2013-03-15 00:35:47 -04:00
Makefile trace: Stop compiling in trace_clock unconditionally 2012-09-13 22:52:08 -04:00
power-traces.c
ring_buffer_benchmark.c tracing: Use NUMA allocation for per-cpu ring buffer pages 2011-06-14 22:04:39 -04:00
ring_buffer.c ring-buffer: Do not use schedule_work_on() for current CPU 2013-03-15 00:35:52 -04:00
rpm-traces.c PM / Runtime: Introduce trace points for tracing rpm_* functions 2011-09-27 22:53:27 +02:00
trace_branch.c tracing: Fix the branch tracer that broke with buffer change 2013-03-15 00:35:54 -04:00
trace_clock.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 17:49:41 -08:00
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_filter_test.h tracing/filter: Add startup tests for events filter 2011-08-19 14:35:59 -04:00
trace_events_filter.c tracing: Separate out trace events from global variables 2013-03-15 00:34:40 -04:00
trace_events.c tracing: Add a way to soft disable trace events 2013-03-15 00:36:03 -04:00
trace_export.c tracing: Fix some section mismatch warnings 2013-03-15 00:34:54 -04:00
trace_functions_graph.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_functions.c ftrace: Separate unlimited probes from count limited probes 2013-03-15 00:35:59 -04:00
trace_irqsoff.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -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: Use irq_work for wake ups and remove *_nowake_*() functions 2012-11-02 10:21:52 -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
trace_output.c tracing: Add trace_puts() for even faster trace_printk() tracing 2013-03-15 00:35:55 -04:00
trace_output.h tracing: Add trace_puts() for even faster trace_printk() tracing 2013-03-15 00:35:55 -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: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_selftest_dynamic.c ftrace: Add self-tests for multiple function trace users 2011-05-18 19:24:51 -04:00
trace_selftest.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_stack.c tracing: Remove unneeded checks from the stack tracer 2012-11-19 15:07:13 -05:00
trace_stat.c
trace_stat.h
trace_syscalls.c tracing: Consolidate max_tr into main trace_array structure 2013-03-15 00:35:40 -04:00
trace_uprobe.c uprobes/perf: Avoid uprobe_apply() whenever possible 2013-02-08 18:28:08 +01:00
trace.c tracing: Add snapshot trigger to function probes 2013-03-15 00:36:01 -04:00
trace.h tracing: Add internal ftrace trace_puts() for ftrace to use 2013-03-15 00:35:56 -04:00