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path: root/include/linux/trace_seq.h
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2009-12-09tracing: Add full state to trace_seqJohannes Berg
The trace_seq buffer might fill up, and right now one needs to check the return value of each printf into the buffer to check for that. Instead, have the buffer keep track of whether it is full or not, and reject more input if it is full or would have overflowed with an input that wasn't added. Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-09tracing: Buffer the output of seq_file in case of filled bufferSteven Rostedt
If the seq_read fills the buffer it will call s_start again on the next itertation with the same position. This causes a problem with the function_graph tracer because it consumes the iteration in order to determine leaf functions. What happens is that the iterator stores the entry, and the function graph plugin will look at the next entry. If that next entry is a return of the same function and task, then the function is a leaf and the function_graph plugin calls ring_buffer_read which moves the ring buffer iterator forward (the trace iterator still points to the function start entry). The copying of the trace_seq to the seq_file buffer will fail if the seq_file buffer is full. The seq_read will not show this entry. The next read by userspace will cause seq_read to again call s_start which will reuse the trace iterator entry (the function start entry). But the function return entry was already consumed. The function graph plugin will think that this entry is a nested function and not a leaf. To solve this, the trace code now checks the return status of the seq_printf (trace_print_seq). If the writing to the seq_file buffer fails, we set a flag in the iterator (leftover) and we do not reset the trace_seq buffer. On the next call to s_start, we check the leftover flag, and if it is set, we just reuse the trace_seq buffer and do not call into the plugin print functions. Before this patch: 2) | fput() { 2) | __fput() { 2) 0.550 us | inotify_inode_queue_event(); 2) | __fsnotify_parent() { 2) 0.540 us | inotify_dentry_parent_queue_event(); After the patch: 2) | fput() { 2) | __fput() { 2) 0.550 us | inotify_inode_queue_event(); 2) 0.548 us | __fsnotify_parent(); 2) 0.540 us | inotify_dentry_parent_queue_event(); [ Updated the patch to fix a missing return 0 from the trace_print_seq() stub when CONFIG_TRACING is disabled. Reported-by: Ingo Molnar <mingo@elte.hu> ] Reported-by: Jiri Olsa <jolsa@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-10-24tracing: Remove cpu arg from the rb_time_stamp() functionJiri Olsa
The cpu argument is not used inside the rb_time_stamp() function. Plus fix a typo. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233647.118547500@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-15tracing: fix undeclared 'PAGE_SIZE' in include/linux/trace_seq.hWu Zhangjin
when compiling linux-mips with kmemtrace enabled, there will be an error: include/linux/trace_seq.h:12: error: 'PAGE_SIZE' undeclared here (not in a function) I checked the source code and found trace_seq.h used PAGE_SIZE but not included the relative header file, so, fix it via adding the header file <asm/page.h> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Wu Zhangjin <wuzj@lemote.com> LKML-Reference: <1244962350-28702-1-git-send-email-wuzhangjin@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-09tracing: add trace_seq_vprint interfaceSteven Rostedt
The code to update the print formats for events requires a vprintf format in the trace_seq. This patch adds that interface. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-20tracing: remove dangling semicolonSteven Rostedt
Due to a cut and paste error, the trace_seq_putc had a semicolon after the prototype but before the stub function when tracing is disabled. [Impact: fix compile error ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-18tracing: remove format attribute of inline functionSteven Rostedt
Due to a cut and paste error, I added the gcc attribute for printf format to the static inline stub of trace_seq_printf. This will cause a compile failure. [ Impact: fix compiler error when CONFIG_TRACING is off ] Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: =?ISO-8859-15?Q?Fr=E9d=E9ric_Weisbecker?= <fweisbec@gmail.com> LKML-Reference: <alpine.DEB.2.00.0904171717080.1016@gandalf.stny.rr.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14tracing/events: add support for modules to TRACE_EVENTSteven Rostedt
Impact: allow modules to add TRACE_EVENTS on load This patch adds the final hooks to allow modules to use the TRACE_EVENT macro. A notifier and a data structure are used to link the TRACE_EVENTs defined in the module to connect them with the ftrace event tracing system. It also adds the necessary automated clean ups to the trace events when a module is removed. Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14tracing: make trace_seq operations available for core kernelSteven Rostedt
In the process to make TRACE_EVENT macro work for modules, the trace_seq operations must be available for core kernel code. These operations are quite useful and can be used for other implementations. The main idea is that we create a trace_seq handle that acts very much like the seq_file handle. struct trace_seq *s = kmalloc(sizeof(*s, GFP_KERNEL); trace_seq_init(s); trace_seq_printf(s, "some data %d\n", variable); printk("%s", s->buffer); The main use is to allow a top level function call several other functions that may store printf like data into the buffer. Then at the end, the top level function can process all the data with any method it would like to. It could be passed to userspace, output via printk or even use seq_file: trace_seq_to_user(s, ubuf, cnt); seq_puts(m, s->buffer); Signed-off-by: Steven Rostedt <rostedt@goodmis.org>