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* trace_stat: Fix missing entry in stat fileLi Zefan2009-08-17
| | | | | | | | | | | | | | One entry is missing in the output of a stat file. The cause is, when stat_seq_start() is called the 2nd time, we should start from the (pos-1)th elem in the rbtree but not pos, because pos == 0 is the header. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A891A65.70009@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'linus' into tracing/coreIngo Molnar2009-08-11
|\ | | | | | | | | | | | | | | | | Conflicts: kernel/trace/trace_events_filter.c We use the tracing/core version. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * tracing/stat: Fix seqfile memory leakLi Zefan2009-07-23
| | | | | | | | | | | | | | | | | | | | | | Every time we cat a trace_stat file, we leak memory allocated by seq_open(). Also fix memory leak in a failure path in tracing_stat_open(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4A67D92B.4060704@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | tracing/stat: Add stat_release() callbackLai Jiangshan2009-07-10
|/ | | | | | | | | | | | | Add stat_release() callback to struct tracer_stat, so a stat tracer can release it's entries after the stat file has been read out. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A51B16A.6020708@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* trace_stat: Don't increment @pos in seq start()Li Zefan2009-06-24
| | | | | | | | | | | | | It's wrong to increment @pos in stat_seq_start(). It causes some stat entries lost when reading stat file, if the output of the file is larger than PAGE_SIZE. Reviewed-by: Liming Wang <liming.wang@windriver.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <4A418716.90209@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/stat: remove unappropriate safe walk on listFrederic Weisbecker2009-06-01
| | | | | | | | | | | register_stat_tracer() uses list_for_each_entry_safe to check whether a tracer is already present in the list. But we don't delete anything from the list here, so we don't need the safe version [ Impact: cleanup list use is stat tracing ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* tracing/stat: do some cleanupsLi Zefan2009-06-01
| | | | | | | | | | - remove duplicate code in stat_seq_init() - update comments to reflect the change from stat list to stat rbtree [ Impact: clean up ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* tracing/stat: remember to free root nodeLi Zefan2009-06-01
| | | | | | | | | | When closing a trace_stat file, we destroy the rbtree constructed during file open, but there is memory leak that the root node is not freed. [ Impact: fix memory leak when closing a trace_stat file ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* tracing/stat: change dummpy_cmp() to return -1Li Zefan2009-06-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the output of trace_stat/workqueues is totally reversed: # cat /debug/tracing/trace_stat/workqueues ... 1 17 17 210 37 `-blk_unplug_work+0x0/0x57 1 3779 3779 181 11 |-cfq_kick_queue+0x0/0x2f 1 3796 3796 kblockd/1:120 ... The correct output should be: 1 3796 3796 kblockd/1:120 1 3779 3779 181 11 |-cfq_kick_queue+0x0/0x2f 1 17 17 210 37 `-blk_unplug_work+0x0/0x57 It's caused by "tracing/stat: replace linked list by an rbtree for sorting" (53059c9b67a62a3dc8c80204d3da42b9267ea5a0). dummpy_cmp() should return -1, so rb_node will always be inserted as right-most node in the rbtree, thus we sort the output in ascending order. [ Impact: fix the output of trace_stat/workqueues ] Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* tracing/stat: replace linked list by an rbtree for sortingFrederic Weisbecker2009-06-01
| | | | | | | | | | | | | | | | | | | | | | | When the stat tracing framework prepares the entries from a tracer to output them to the user, it starts by computing a linear sort through a linked list to give the entries ordered by relevance to the user. This is quite ugly and causes a small latency when we begin to read the file. This patch changes that by turning the linked list into a red-black tree. Athough the whole iteration using the start and next tracer callbacks while opening the file remain the same, it is now much more fast and scalable. The rbtree guarantees O(log(n)) insertions whereas a linked list with linear sorting brought us a O(n) despair. Now the (visible) latency has disapeared. [ Impact: kill the latency while starting to read a stat tracer file ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* tracing/stat: replace trace_stat_session by stat_sessionFrederic Weisbecker2009-06-01
| | | | | | | | | | | | The "trace" prefix in struct trace_stat_session type is annoying while reading the trace_stat.c file. It makes the lines longer, and is not that much useful to explain the sense of this type. Just keep "struct stat_session" for this type. [ Impact: make the code a bit more readable ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* Merge branch 'linus' into tracing/coreIngo Molnar2009-04-07
|\ | | | | | | | | | | Merge reason: update to upstream tracing facilities Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * trace_stat: keep original orderLai Jiangshan2009-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: make trace_stat files show items with the original order trace_stat tracer reverse the items, it makes the output looks a little ugly. Example, when we read trace_stat/workqueues, we get cpu#7's stat. at first, and then cpu#6... cpu#0. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <49C9F23F.5040307@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * trace_stat: don't call seq_printf() in seq_operation->start()Lai Jiangshan2009-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | | Impact: Fix incorrect way using seq_file's API Use SEQ_START_TOKEN instead of calling ->stat_headers() int seq_operation->start(). Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> LKML-Reference: <49C9EAE5.5070202@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing: add handler to trace_statSteven Rostedt2009-03-24
|/ | | | | | | | | | Currently, if a trace_stat user wants a handle to some private data, the trace_stat infrastructure does not supply a way to do that. This patch passes the trace_stat structure to the start function of the trace_stat code. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
* tracing: fix memory leak in trace_statSteven Rostedt2009-03-24
| | | | | | | | | | | | | | | | | | | | | If the function profiler does not have any items recorded and one were to cat the function stat file, the kernel would take a BUG with a NULL pointer dereference. Looking further into this, I found that returning NULL from stat_start did not stop the stat logic, and would later call stat_next. This breaks from the way seq_file works, so I looked into fixing the stat code. This is where I noticed that the last next_entry is never freed. It is allocated, and if the stat_next returns NULL, the code breaks out of the loop, unlocks the mutex and exits. We never link the next_entry nor do we free it. Thus it is a real memory leak. This patch rearranges the code a bit to not only fix the memory leak, but also to act more like seq_file where nothing is printed if there is nothing to print. That is, stat_start returns NULL. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
* tracing: fix typing mistake in hint message and commentsWenji Huang2009-02-17
| | | | | | | | | Impact: cleanup Fix incorrect hint message in code and typos in comments. Signed-off-by: Wenji Huang <wenji.huang@oracle.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
* tracing: trace_stat.c cleanupIngo Molnar2009-01-15
| | | | | | | | | Impact: cleanup - whitespace / code alignment cleanups - avoid unnecessary forward prototype by reordering functions Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/ftrace: add missing unlock in register_stat_tracer()Li Zefan2009-01-15
| | | | | | | | We should unlock all_stat_sessions_mutex before returning failure. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/ftrace: separate events tracing and stats tracing engineFrederic Weisbecker2009-01-14
| | | | | | | | | | | | | | | | | Impact: tracing's Api change Currently, the stat tracing depends on the events tracing. When you switch to a new tracer, the stats files of the previous tracer will disappear. But it's more scalable to separate those two engines. This way, we can keep the stat files of one or several tracers when we want, without bothering of multiple tracer stat files or tracer switching. To build/destroys its stats files, a tracer just have to call register_stat_tracer/unregister_stat_tracer everytimes it wants to. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/ftrace: handle more than one stat file per tracerFrederic Weisbecker2009-01-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: new API for tracers Make the stat tracing API reentrant. And also provide the new directory /debugfs/tracing/trace_stat which will contain all the stat files for the current active tracer. Now a tracer will, if desired, want to provide a zero terminated array of tracer_stat structures. Each one contains the callbacks necessary for one stat file. It have to provide at least a name for its stat file, an iterator with stat_start/start_next callback and an output callback for one stat entry. Also adapt the branch tracer to this new API. We create two files "all" and "annotated" inside the /debugfs/tracing/trace_stat directory, making the both stats simultaneously available instead of needing to change an option to switch from one stat file to another. The output of these stats haven't changed. Changes in v2: _ Apply the previous memory leak fix (rebase against tip/master) Changes in v3: _ Merge the patch that adapted the branch tracer to this Api in this patch to not break the kernel build. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* trace: clean up funny line breaks in stat_seq_showSteven Rostedt2009-01-07
| | | | | | | | | | | | Impact: clean up Andrew Morton pointed out that the entry assignment in stat_seq_show did not need to be done in the declaration, causing funny line breaks. This patch makes it a bit more pleasing on the eyes. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/ftrace: fix a memory leak in stat tracingFrederic Weisbecker2009-01-07
| | | | | | | | | | | | | | | Impact: fix memory leak This patch fixes a memory leak inside reset_stat_list(). The freeing loop iterated only once. Also turn the stat_list into a simple struct list_head, which simplify the code and avoid an unused static pointer. Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* tracing/ftrace: provide the base infrastructure for histogram tracingFrederic Weisbecker2008-12-29
Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>