user/sven/linux.git/kernel/trace/ring_buffer.c, branch v3.10

ring-buffer: Do not poll non allocated cpu buffers

2013-05-28T14:53:20Z

The tracing infrastructure sets up for possible CPUs, but it uses the ring buffer polling, it is possible to call the ring buffer polling code with a CPU that hasn't been allocated. This will cause a kernel oops when it access a ring buffer cpu buffer that is part of the possible cpus but hasn't been allocated yet as the CPU has never been online. Reported-by: Mauro Carvalho Chehab Tested-by: Mauro Carvalho Chehab Signed-off-by: Steven Rostedt

Merge tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2013-04-29T20:55:38Z

Pull tracing updates from Steven Rostedt: "Along with the usual minor fixes and clean ups there are a few major changes with this pull request. 1) Multiple buffers for the ftrace facility This feature has been requested by many people over the last few years. I even heard that Google was about to implement it themselves. I finally had time and cleaned up the code such that you can now create multiple instances of the ftrace buffer and have different events go to different buffers. This way, a low frequency event will not be lost in the noise of a high frequency event. Note, currently only events can go to different buffers, the tracers (ie function, function_graph and the latency tracers) still can only be written to the main buffer. 2) The function tracer triggers have now been extended. The function tracer had two triggers. One to enable tracing when a function is hit, and one to disable tracing. Now you can record a stack trace on a single (or many) function(s), take a snapshot of the buffer (copy it to the snapshot buffer), and you can enable or disable an event to be traced when a function is hit. 3) A perf clock has been added. A "perf" clock can be chosen to be used when tracing. This will cause ftrace to use the same clock as perf uses, and hopefully this will make it easier to interleave the perf and ftrace data for analysis." * tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (82 commits) tracepoints: Prevent null probe from being added tracing: Compare to 1 instead of zero for is_signed_type() tracing: Remove obsolete macro guard _TRACE_PROFILE_INIT ftrace: Get rid of ftrace_profile_bits tracing: Check return value of tracing_init_dentry() tracing: Get rid of unneeded key calculation in ftrace_hash_move() tracing: Reset ftrace_graph_filter_enabled if count is zero tracing: Fix off-by-one on allocating stat->pages kernel: tracing: Use strlcpy instead of strncpy tracing: Update debugfs README file tracing: Fix ftrace_dump() tracing: Rename trace_event_mutex to trace_event_sem tracing: Fix comment about prefix in arch_syscall_match_sym_name() tracing: Convert trace_destroy_fields() to static tracing: Move find_event_field() into trace_events.c tracing: Use TRACE_MAX_PRINT instead of constant tracing: Use pr_warn_once instead of open coded implementation ring-buffer: Add ring buffer startup selftest tracing: Bring Documentation/trace/ftrace.txt up to date tracing: Add "perf" trace_clock ... Conflicts: kernel/trace/ftrace.c kernel/trace/trace.c

ring-buffer: Add ring buffer startup selftest

2013-03-15T17:21:16Z

When testing my large changes to the ftrace system, there was a bug that looked like the ring buffer was dropping events. I wrote up a quick integrity checker of the ring buffer to see if it was. Although the bug ended up being something stupid I did in ftrace, and had nothing to do with the ring buffer, I figured if I spent the time to write up this test, I might as well include it in the kernel. I cleaned it up a bit, as the original version was rather ugly. Not saying this version is pretty, but it's a beauty queen compared to what I original wrote. To enable the start up test, set CONFIG_RING_BUFFER_STARTUP_TEST. Note, it runs for 10 seconds, so it will slow your boot time by at least 10 more seconds. What it does is documented in both the comments and the Kconfig help. Signed-off-by: Steven Rostedt

ring-buffer: Do not use schedule_work_on() for current CPU

2013-03-15T04:35:52Z

The ring buffer updates when done while the ring buffer is active, needs to be completed on the CPU that is used for the ring buffer per_cpu buffer. To accomplish this, schedule_work_on() is used to schedule work on the given CPU. Now there's no reason to use schedule_work_on() if the process doing the update happens to be on the CPU that it is processing. It has already filled the requirement. Instead, just do the work and continue. This is needed for tracing_snapshot_alloc() where it may be called really early in boot, where the work queues have not been set up yet. Signed-off-by: Steven Rostedt

ring-buffer: Init waitqueue for blocked readers

2013-03-15T04:34:55Z

The move of blocked readers to the ring buffer left out the init of the wait queue that is used. Tests missed this due to running stress tests against the buffers, which didn't allow for any readers to end up waiting. Running a simple read and wait triggered a bug. Signed-off-by: Steven Rostedt

tracing/ring-buffer: Move poll wake ups into ring buffer code

2013-03-15T04:34:50Z

Move the logic to wake up on ring buffer data into the ring buffer code itself. This simplifies the tracing code a lot and also has the added benefit that waiters on one of the instance buffers can be woken only when data is added to that instance instead of data added to any instance. Signed-off-by: Steven Rostedt

Merge tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag

2013-03-03T20:06:09Z

Pull new ImgTec Meta architecture from James Hogan: "This adds core architecture support for Imagination's Meta processor cores, followed by some later miscellaneous arch/metag cleanups and fixes which I kept separate to ease review: - Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture - A few fixes all over, particularly for symbol prefixes - A few privilege protection fixes - Several cleanups (setup.c includes, split out a lot of metag_ksyms.c) - Fix some missing exports - Convert hugetlb to use vm_unmapped_area() - Copy device tree to non-init memory - Provide dma_get_sgtable()" * tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits) metag: Provide dma_get_sgtable() metag: prom.h: remove declaration of metag_dt_memblock_reserve() metag: copy devicetree to non-init memory metag: cleanup metag_ksyms.c includes metag: move mm/init.c exports out of metag_ksyms.c metag: move usercopy.c exports out of metag_ksyms.c metag: move setup.c exports out of metag_ksyms.c metag: move kick.c exports out of metag_ksyms.c metag: move traps.c exports out of metag_ksyms.c metag: move irq enable out of irqflags.h on SMP genksyms: fix metag symbol prefix on crc symbols metag: hugetlb: convert to vm_unmapped_area() metag: export clear_page and copy_page metag: export metag_code_cache_flush_all metag: protect more non-MMU memory regions metag: make TXPRIVEXT bits explicit metag: kernel/setup.c: sort includes perf: Enable building perf tools for Meta metag: add boot time LNKGET/LNKSET check metag: add __init to metag_cache_probe() ...

trace/ring_buffer: handle 64bit aligned structs

2013-03-02T20:09:16Z

Some 32 bit architectures require 64 bit values to be aligned (for example Meta which has 64 bit read/write instructions). These require 8 byte alignment of event data too, so use !CONFIG_HAVE_64BIT_ALIGNED_ACCESS instead of !CONFIG_64BIT || CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to decide alignment, and align buffer_data_page::data accordingly. Signed-off-by: James Hogan Cc: Frederic Weisbecker Cc: Ingo Molnar Acked-by: Steven Rostedt (previous version subtly different)

ring-buffer: Add stats field for amount read from trace ring buffer

2013-01-30T16:01:53Z

Add a stat about the number of events read from the ring buffer: # cat /debug/tracing/per_cpu/cpu0/stats entries: 39869 overrun: 870512 commit overrun: 0 bytes: 1449912 oldest event ts: 6561.368690 now ts: 6565.246426 dropped events: 0 read events: 112 <-- Added Signed-off-by: Steven Rostedt

ring-buffer: Remove trace.h from ring_buffer.c

2013-01-23T04:38:03Z

ring_buffer.c use to require declarations from trace.h, but these have moved to the generic header files. There's nothing in trace.h that ring_buffer.c requires. There's some headers that trace.h included that ring_buffer.c needs, but it's best that it includes them directly, and not include trace.h. Also, some things may use ring_buffer.c without having tracing configured. This removes the dependency that may come in the future. Signed-off-by: Steven Rostedt