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linux-next/include/linux/trace_seq.h

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tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
#ifndef _LINUX_TRACE_SEQ_H
#define _LINUX_TRACE_SEQ_H
tracing/events: add support for modules to TRACE_EVENT 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>
2009-04-11 02:53:50 +08:00
#include <linux/fs.h>
tracing: fix undeclared 'PAGE_SIZE' in include/linux/trace_seq.h 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>
2009-06-14 14:52:30 +08:00
#include <asm/page.h>
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
/*
* Trace sequences are used to allow a function to call several other functions
tracing: Remove cpu arg from the rb_time_stamp() function 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>
2009-10-24 07:36:19 +08:00
* to create a string of data to use (up to a max of PAGE_SIZE).
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
*/
struct trace_seq {
unsigned char buffer[PAGE_SIZE];
unsigned int len;
unsigned int readpos;
tracing: Add full state to trace_seq 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>
2009-11-25 23:10:14 +08:00
int full;
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
};
static inline void
trace_seq_init(struct trace_seq *s)
{
s->len = 0;
s->readpos = 0;
tracing: Add full state to trace_seq 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>
2009-11-25 23:10:14 +08:00
s->full = 0;
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
}
/*
* Currently only defined when tracing is enabled.
*/
#ifdef CONFIG_TRACING
treewide: use __printf not __attribute__((format(printf,...))) Standardize the style for compiler based printf format verification. Standardized the location of __printf too. Done via script and a little typing. $ grep -rPl --include=*.[ch] -w "__attribute__" * | \ grep -vP "^(tools|scripts|include/linux/compiler-gcc.h)" | \ xargs perl -n -i -e 'local $/; while (<>) { s/\b__attribute__\s*\(\s*\(\s*format\s*\(\s*printf\s*,\s*(.+)\s*,\s*(.+)\s*\)\s*\)\s*\)/__printf($1, $2)/g ; print; }' [akpm@linux-foundation.org: revert arch bits] Signed-off-by: Joe Perches <joe@perches.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-01 08:11:33 +08:00
extern __printf(2, 3)
int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
extern __printf(2, 0)
int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args);
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
extern int
trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary);
tracing: Buffer the output of seq_file in case of filled buffer 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>
2009-12-07 22:11:39 +08:00
extern int trace_print_seq(struct seq_file *m, struct trace_seq *s);
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
size_t cnt);
extern int trace_seq_puts(struct trace_seq *s, const char *str);
extern int trace_seq_putc(struct trace_seq *s, unsigned char c);
extern int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len);
extern int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
size_t len);
extern void *trace_seq_reserve(struct trace_seq *s, size_t len);
constify path argument of trace_seq_path() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-15 09:51:10 +08:00
extern int trace_seq_path(struct trace_seq *s, const struct path *path);
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
#else /* CONFIG_TRACING */
static inline int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
return 0;
}
static inline int
trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
{
return 0;
}
tracing: Buffer the output of seq_file in case of filled buffer 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>
2009-12-07 22:11:39 +08:00
static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s)
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
{
tracing: Buffer the output of seq_file in case of filled buffer 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>
2009-12-07 22:11:39 +08:00
return 0;
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
}
static inline ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
size_t cnt)
{
return 0;
}
static inline int trace_seq_puts(struct trace_seq *s, const char *str)
{
return 0;
}
tracing: remove dangling semicolon 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>
2009-04-21 00:59:29 +08:00
static inline int trace_seq_putc(struct trace_seq *s, unsigned char c)
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
{
return 0;
}
static inline int
trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
{
return 0;
}
static inline int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
size_t len)
{
return 0;
}
static inline void *trace_seq_reserve(struct trace_seq *s, size_t len)
{
return NULL;
}
constify path argument of trace_seq_path() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-15 09:51:10 +08:00
static inline int trace_seq_path(struct trace_seq *s, const struct path *path)
tracing: make trace_seq operations available for core kernel 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>
2009-04-12 00:59:57 +08:00
{
return 0;
}
#endif /* CONFIG_TRACING */
#endif /* _LINUX_TRACE_SEQ_H */
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