user/sven/linux.git/kernel/trace/trace.c, branch v3.0.50

tracing: change CPU ring buffer state from tracing_cpumask

2012-07-16T15:47:51Z

commit 71babb2705e2203a64c27ede13ae3508a0d2c16c upstream. According to Documentation/trace/ftrace.txt: tracing_cpumask: This is a mask that lets the user only trace on specified CPUS. The format is a hex string representing the CPUS. The tracing_cpumask currently doesn't affect the tracing state of per-CPU ring buffers. This patch enables/disables CPU recording as its corresponding bit in tracing_cpumask is set/unset. Link: http://lkml.kernel.org/r/1336096792-25373-3-git-send-email-vnagarnaik@google.com Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Laurent Chavey Cc: Justin Teravest Cc: David Sharp Signed-off-by: Vaibhav Nagarnaik Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

tracing: Fix returning of duplicate data after EOF in trace_pipe_raw

2011-11-11T17:35:53Z

commit 436fc280261dcfce5af38f08b89287750dc91cd2 upstream. The trace_pipe_raw handler holds a cached page from the time the file is opened to the time it is closed. The cached page is used to handle the case of the user space buffer being smaller than what was read from the ring buffer. The left over buffer is held in the cache so that the next read will continue where the data left off. After EOF is returned (no more data in the buffer), the index of the cached page is set to zero. If a user app reads the page again after EOF, the check in the buffer will see that the cached page is less than page size and will return the cached page again. This will cause reading the trace_pipe_raw again after EOF to return duplicate data, making the output look like the time went backwards but instead data is just repeated. The fix is to not reset the index right after all data is read from the cache, but to reset it after all data is read and more data exists in the ring buffer. Reported-by: Jeremy Eder Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman

Merge commit 'v2.6.39-rc7' into perf/core

2011-05-10T15:05:45Z

Merge reason: pull in the latest fixes. Signed-off-by: Ingo Molnar

Regression: partial revert "tracing: Remove lock_depth from event entry"

2011-05-06T20:20:59Z

This partially reverts commit e6e1e2593592a8f6f6380496655d8c6f67431266. That commit changed the structure layout of the trace structure, which in turn broke PowerTOP (1.9x generation) quite badly. I appreciate not wanting to expose the variable in question, and PowerTOP was not using it, so I've replaced the variable with just a padding field - that way if in the future a new field is needed it can just use this padding field. Signed-off-by: Arjan van de Ven Signed-off-by: Linus Torvalds

Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core

2011-04-27T08:40:21Z

Conflicts: include/linux/perf_event.h Merge reason: pick up the latest jump-label enhancements, they are cooked ready. Signed-off-by: Ingo Molnar

tracing: Avoid soft lockup in trace_pipe

2011-04-04T16:18:24Z

running following commands: # enable the binary option echo 1 > ./options/bin # disable context info option echo 0 > ./options/context-info # tracing only events echo 1 > ./events/enable cat trace_pipe plus forcing system to generate many tracing events, is causing lockup (in NON preemptive kernels) inside tracing_read_pipe function. The issue is also easily reproduced by running ltp stress test. (ftrace_stress_test.sh) The reasons are: - bin/hex/raw output functions for events are set to trace_nop_print function, which prints nothing and returns TRACE_TYPE_HANDLED value - LOST EVENT trace do not handle trace_seq overflow These reasons force the while loop in tracing_read_pipe function never to break. The attached patch fixies handling of lost event trace, and changes trace_nop_print to print minimal info, which is needed for the correct tracing_read_pipe processing. v2 changes: - omit the cond_resched changes by trace_nop_print changes - WARN changed to WARN_ONCE and added info to be able to find out the culprit v3 changes: - make more accurate patch comment Signed-off-by: Jiri Olsa LKML-Reference: <20110325110518.GC1922@jolsa.brq.redhat.com> Signed-off-by: Steven Rostedt

Fix common misspellings

2011-03-31T14:26:23Z

Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi

tracing: Fix irqoff selftest expanding max buffer

2011-03-10T15:34:58Z

If the kernel command line declares a tracer "ftrace=sometracer" and that tracer is either not defined or is enabled after irqsoff, then the irqs off selftest will fail with the following error: Testing tracer irqsoff: ------------[ cut here ]------------ WARNING: at /home/rostedt/work/autotest/nobackup/linux-test.git/kernel/trace/tra ce.c:713 update_max_tr_single+0xfa/0x11b() Hardware name: Modules linked in: Pid: 1, comm: swapper Not tainted 2.6.38-rc8-test #1 Call Trace: [] ? warn_slowpath_common+0x65/0x7a [] ? update_max_tr_single+0xfa/0x11b [] ? warn_slowpath_null+0xf/0x13 [] ? update_max_tr_single+0xfa/0x11b [] ? stop_critical_timing+0x154/0x204 [] ? trace_selftest_startup_irqsoff+0x5b/0xc1 [] ? trace_selftest_startup_irqsoff+0x5b/0xc1 [] ? trace_selftest_startup_irqsoff+0x5b/0xc1 [] ? time_hardirqs_on+0x25/0x28 [] ? trace_hardirqs_on_caller+0x18/0x12f [] ? trace_hardirqs_on+0xb/0xd [] ? trace_selftest_startup_irqsoff+0x5b/0xc1 [] ? register_tracer+0xf8/0x1a3 [] ? init_irqsoff_tracer+0xd/0x11 [] ? do_one_initcall+0x71/0x121 [] ? init_irqsoff_tracer+0x0/0x11 [] ? kernel_init+0x13a/0x1b6 [] ? kernel_init+0x0/0x1b6 [] ? kernel_thread_helper+0x6/0x10 ---[ end trace e93713a9d40cd06c ]--- .. no entries found ..FAILED! What happens is the "ftrace=..." will expand the ring buffer to its default size (from its minimum size) but it will not expand the max ring buffer (the ring buffer to store maximum latencies). When the irqsoff test runs, it will call the ring buffer swap routine that checks if the max ring buffer is the same size as the normal ring buffer, and will fail if it is not. This causes the test to fail. The solution is to expand the max ring buffer before running the self test if the max ring buffer is used by that tracer and the normal ring buffer is expanded. The max ring buffer should be shrunk again after the test is done to save space. Signed-off-by: Steven Rostedt

tracing: Remove lock_depth from event entry

2011-03-10T15:31:48Z

The lock_depth field in the event headers was added as a temporary data point for help in removing the BKL. Now that the BKL is pretty much been removed, we can remove this field. This in turn changes the header from 12 bytes to 8 bytes, removing the 4 byte buffer that gcc would insert if the first field in the data load was 8 bytes in size. Signed-off-by: Steven Rostedt

tracing: Add an 'overwrite' trace_option.

2011-03-09T18:52:27Z

Add an "overwrite" trace_option for ftrace to control whether the buffer should be overwritten on overflow or not. The default remains to overwrite old events when the buffer is full. This patch adds the option to instead discard newest events when the buffer is full. This is useful to get a snapshot of traces just after enabling traces. Dropping the current event is also a simpler code path. Signed-off-by: David Sharp LKML-Reference: <1291844807-15481-1-git-send-email-dhsharp@google.com> Signed-off-by: Steven Rostedt