kernel-ark/tools/virtio/virtio-trace/trace-agent.h
Yoshihiro YUNOMAE 108fc82596 tools: Add guest trace agent as a user tool
This patch adds a user tool, "trace agent" for sending trace data of a guest to
a Host in low overhead. This agent has the following functions:
 - splice a page of ring-buffer to read_pipe without memory copying
 - splice the page from write_pipe to virtio-console without memory copying
 - write trace data to stdout by using -o option
 - controlled by start/stop orders from a Host

Changes in v2:
 - Cleanup (change fprintf() to pr_err() and an include guard)

Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-28 15:05:13 +09:30

76 lines
2.1 KiB
C

#ifndef __TRACE_AGENT_H__
#define __TRACE_AGENT_H__
#include <pthread.h>
#include <stdbool.h>
#define MAX_CPUS 256
#define PIPE_INIT (1024*1024)
/*
* agent_info - structure managing total information of guest agent
* @pipe_size: size of pipe (default 1MB)
* @use_stdout: set to true when o option is added (default false)
* @cpus: total number of CPUs
* @ctl_fd: fd of control path, /dev/virtio-ports/agent-ctl-path
* @rw_ti: structure managing information of read/write threads
*/
struct agent_info {
unsigned long pipe_size;
bool use_stdout;
int cpus;
int ctl_fd;
struct rw_thread_info *rw_ti[MAX_CPUS];
};
/*
* rw_thread_info - structure managing a read/write thread a cpu
* @cpu_num: cpu number operating this read/write thread
* @in_fd: fd of reading trace data path in cpu_num
* @out_fd: fd of writing trace data path in cpu_num
* @read_pipe: fd of read pipe
* @write_pipe: fd of write pipe
* @pipe_size: size of pipe (default 1MB)
*/
struct rw_thread_info {
int cpu_num;
int in_fd;
int out_fd;
int read_pipe;
int write_pipe;
unsigned long pipe_size;
};
/* use for stopping rw threads */
extern bool global_sig_receive;
/* use for notification */
extern bool global_run_operation;
extern pthread_mutex_t mutex_notify;
extern pthread_cond_t cond_wakeup;
/* for controller of read/write threads */
extern int rw_ctl_init(const char *ctl_path);
extern void *rw_ctl_loop(int ctl_fd);
/* for trace read/write thread */
extern void *rw_thread_info_new(void);
extern void *rw_thread_init(int cpu, const char *in_path, const char *out_path,
bool stdout_flag, unsigned long pipe_size,
struct rw_thread_info *rw_ti);
extern pthread_t rw_thread_run(struct rw_thread_info *rw_ti);
static inline void *zalloc(size_t size)
{
return calloc(1, size);
}
#define pr_err(format, ...) fprintf(stderr, format, ## __VA_ARGS__)
#define pr_info(format, ...) fprintf(stdout, format, ## __VA_ARGS__)
#ifdef DEBUG
#define pr_debug(format, ...) fprintf(stderr, format, ## __VA_ARGS__)
#else
#define pr_debug(format, ...) do {} while (0)
#endif
#endif /*__TRACE_AGENT_H__*/