linux_dsm_epyc7002/kernel/trace
Steven Rostedt (VMware) 2824f50332 tracing: Make the snapshot trigger work with instances
The snapshot trigger currently only affects the main ring buffer, even when
it is used by the instances. This can be confusing as the snapshot trigger
is listed in the instance.

 > # cd /sys/kernel/tracing
 > # mkdir instances/foo
 > # echo snapshot > instances/foo/events/syscalls/sys_enter_fchownat/trigger
 > # echo top buffer > trace_marker
 > # echo foo buffer > instances/foo/trace_marker
 > # touch /tmp/bar
 > # chown rostedt /tmp/bar
 > # cat instances/foo/snapshot
 # tracer: nop
 #
 #
 # * Snapshot is freed *
 #
 # Snapshot commands:
 # echo 0 > snapshot : Clears and frees snapshot buffer
 # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.
 #                      Takes a snapshot of the main buffer.
 # echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)
 #                      (Doesn't have to be '2' works with any number that
 #                       is not a '0' or '1')

 > # cat snapshot
 # tracer: nop
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |
             bash-1189  [000] ....   111.488323: tracing_mark_write: top buffer

Not only did the snapshot occur in the top level buffer, but the instance
snapshot buffer should have been allocated, and it is still free.

Cc: stable@vger.kernel.org
Fixes: 85f2b08268 ("tracing: Add basic event trigger framework")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-28 12:49:32 -04:00
..
blktrace.c blktrace: fix trace mutex deadlock 2017-11-27 12:03:58 -07:00
bpf_trace.c bpf/tracing: fix a deadlock in perf_event_detach_bpf_prog 2018-04-11 01:01:40 +02:00
ftrace.c ftrace: Have set_graph_* files have normal file modes 2018-05-03 11:55:31 -04:00
Kconfig tracing: Add inter-event blurb to HIST_TRIGGERS config option 2018-03-10 16:06:05 -05:00
Makefile Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
power-traces.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ring_buffer_benchmark.c
ring_buffer.c ring-buffer: Add set/clear_current_oom_origin() during allocations 2018-04-06 08:56:52 -04:00
rpm-traces.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_benchmark.c trace: Eliminate cond_resched_rcu_qs() in favor of cond_resched() 2017-12-04 10:28:58 -08:00
trace_benchmark.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_branch.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_clock.c tracing: Hide global trace clock from lockdep 2018-04-06 08:56:52 -04:00
trace_entries.h tracing: Fix missing tab for hwlat_detector print format 2018-04-25 10:28:46 -04:00
trace_event_perf.c perf/core: Fix perf_uprobe_init() 2018-04-10 07:33:10 +02:00
trace_events_filter_test.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_events_filter.c tracing: Fix regex_match_front() to not over compare the test string 2018-05-11 10:56:42 -04:00
trace_events_hist.c tracing: Add field modifier parsing hist error for hist triggers 2018-04-26 21:39:58 -04:00
trace_events_trigger.c tracing: Make the snapshot trigger work with instances 2018-05-28 12:49:32 -04:00
trace_events.c tracing: Make sure the parsed string always terminates with '\0' 2018-01-23 15:57:28 -05:00
trace_export.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_functions_graph.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_functions.c tracing: Update stack trace skipping for ORC unwinder 2018-01-23 15:57:00 -05:00
trace_hwlat.c
trace_irqsoff.c tracing: Add support for preempt and irq enable/disable events 2017-10-10 18:58:43 -04:00
trace_kdb.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_kprobe.c trace_kprobe: Remove warning message "Could not insert probe at..." 2018-04-17 07:54:57 +02:00
trace_mmiotrace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_nop.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_output.c sched/debug: Rename task-state printing helpers 2017-10-10 11:43:29 +02:00
trace_output.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_printk.c treewide: Align function definition open/close braces 2018-03-26 11:13:09 +02:00
trace_probe.c tracing: probeevent: Fix to support minus offset from symbol 2018-03-23 12:02:37 -04:00
trace_probe.h Merge branch 'perf/urgent' into perf/core 2018-03-29 16:03:48 +02:00
trace_sched_switch.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_sched_wakeup.c Merge branch 'linus' into sched/core, to pick up fixes 2017-11-08 10:17:15 +01:00
trace_selftest_dynamic.c ftrace: Mark function tracer test functions noinline/noclone 2018-01-23 15:57:29 -05:00
trace_selftest.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace_seq.c
trace_stack.c tracing: Fix the file mode of stack tracer 2018-05-03 11:58:05 -04:00
trace_stat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_stat.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_syscalls.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace_uprobe.c tracing: Fix bad use of igrab in trace_uprobe.c 2018-04-26 14:49:55 -04:00
trace.c tracing: Make the snapshot trigger work with instances 2018-05-28 12:49:32 -04:00
trace.h tracing: Make the snapshot trigger work with instances 2018-05-28 12:49:32 -04:00
tracing_map.c tracing: Add per-element variable support to tracing_map 2018-03-10 16:05:53 -05:00
tracing_map.h tracing: Add per-element variable support to tracing_map 2018-03-10 16:05:53 -05:00