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authorLinus Torvalds <torvalds@linux-foundation.org>2021-02-22 14:07:15 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-22 14:07:15 -0800
commitc9584234709aff90fbf38f71904a068ee9e8bce3 (patch)
tree85d0d76c25767b49470eb3f6f2cb9142914c5dae /Documentation
parent3a36281a17199737b468befb826d4a23eb774445 (diff)
parentc85c9a2c6e368dc94907e63babb18a9788e5c9b6 (diff)
Merge tag 'trace-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: - Update to the way irqs and preemption is tracked via the trace event PC field - Fix handling of unregistering event failing due to allocate memory. This is only triggered by failure injection, as it is pretty much guaranteed to have less than a page allocation succeed. - Do not show the useless "filter" or "enable" files for the "ftrace" trace system, as they have no effect on doing anything. - Add a warning if kprobes are registered more than once. - Synthetic events now have their fields parsed by semicolons. Old formats without semicolons will still work, but new features will require them. - New option to allow trace events to show %p without hashing in trace file. The trace file can only be read by root, and reading the raw event buffer did not have any pointers hashed, so this does not expose anything new. - New directory in tools called tools/tracing, where a new tool that reads sequential latency reports from the ftrace latency tracers. - Other minor fixes and cleanups. * tag 'trace-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) kprobes: Fix to delay the kprobes jump optimization tracing/tools: Add the latency-collector to tools directory tracing: Make hash-ptr option default tracing: Add ptr-hash option to show the hashed pointer value tracing: Update the stage 3 of trace event macro comment tracing: Show real address for trace event arguments selftests/ftrace: Add '!event' synthetic event syntax check selftests/ftrace: Update synthetic event syntax errors tracing: Add a backward-compatibility check for synthetic event creation tracing: Update synth command errors tracing: Rework synthetic event command parsing tracing/dynevent: Delegate parsing to create function kprobes: Warn if the kprobe is reregistered ftrace: Remove unused ftrace_force_update() tracepoints: Code clean up tracepoints: Do not punish non static call users tracepoints: Remove unnecessary "data_args" macro parameter tracing: Do not create "enable" or "filter" files for ftrace event subsystem kernel: trace: preemptirq_delay_test: add cpu affinity tracepoint: Do not fail unregistering a probe due to memory failure ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/trace/ftrace.rst6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst
index 87cf5c010d5d..62c98e9bbdd9 100644
--- a/Documentation/trace/ftrace.rst
+++ b/Documentation/trace/ftrace.rst
@@ -1159,6 +1159,12 @@ Here are the available options:
This simulates the original behavior of the trace file.
When the file is closed, tracing will be enabled again.
+ hash-ptr
+ When set, "%p" in the event printk format displays the
+ hashed pointer value instead of real address.
+ This will be useful if you want to find out which hashed
+ value is corresponding to the real value in trace log.
+
record-cmd
When any event or tracer is enabled, a hook is enabled
in the sched_switch trace point to fill comm cache