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![Peter Zijlstra](/assets/img/avatar_default.png)
Up until now record has worked on the assumption that type=0, config=0 was a suitable configuration - which it is. Lets make this a little more explicit and more readable via the use of proper symbols. [ Impact: cleanup ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
585 lines
13 KiB
C
585 lines
13 KiB
C
/*
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* builtin-record.c
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*
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* Builtin record command: Record the profile of a workload
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* (or a CPU, or a PID) into the perf.data output file - for
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* later analysis via perf report.
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*/
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#include "builtin.h"
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#include "perf.h"
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#include "util/util.h"
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#include "util/parse-options.h"
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#include "util/parse-events.h"
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#include "util/string.h"
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#include <unistd.h>
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#include <sched.h>
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#define ALIGN(x, a) __ALIGN_MASK(x, (typeof(x))(a)-1)
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#define __ALIGN_MASK(x, mask) (((x)+(mask))&~(mask))
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static int fd[MAX_NR_CPUS][MAX_COUNTERS];
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static long default_interval = 100000;
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static int nr_cpus = 0;
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static unsigned int page_size;
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static unsigned int mmap_pages = 128;
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static int freq = 0;
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static int output;
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static const char *output_name = "perf.data";
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static int group = 0;
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static unsigned int realtime_prio = 0;
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static int system_wide = 0;
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static pid_t target_pid = -1;
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static int inherit = 1;
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static int force = 0;
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static int append_file = 0;
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static int verbose = 0;
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static long samples;
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static struct timeval last_read;
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static struct timeval this_read;
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static __u64 bytes_written;
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static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
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static int nr_poll;
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static int nr_cpu;
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struct mmap_event {
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struct perf_event_header header;
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__u32 pid;
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__u32 tid;
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__u64 start;
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__u64 len;
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__u64 pgoff;
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char filename[PATH_MAX];
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};
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struct comm_event {
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struct perf_event_header header;
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__u32 pid;
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__u32 tid;
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char comm[16];
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};
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struct mmap_data {
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int counter;
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void *base;
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unsigned int mask;
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unsigned int prev;
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};
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static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
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static unsigned int mmap_read_head(struct mmap_data *md)
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{
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struct perf_counter_mmap_page *pc = md->base;
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int head;
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head = pc->data_head;
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rmb();
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return head;
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}
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static void mmap_read(struct mmap_data *md)
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{
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unsigned int head = mmap_read_head(md);
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unsigned int old = md->prev;
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unsigned char *data = md->base + page_size;
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unsigned long size;
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void *buf;
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int diff;
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gettimeofday(&this_read, NULL);
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/*
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* If we're further behind than half the buffer, there's a chance
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* the writer will bite our tail and mess up the samples under us.
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*
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* If we somehow ended up ahead of the head, we got messed up.
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*
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* In either case, truncate and restart at head.
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*/
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diff = head - old;
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if (diff > md->mask / 2 || diff < 0) {
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struct timeval iv;
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unsigned long msecs;
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timersub(&this_read, &last_read, &iv);
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msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
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fprintf(stderr, "WARNING: failed to keep up with mmap data."
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" Last read %lu msecs ago.\n", msecs);
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/*
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* head points to a known good entry, start there.
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*/
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old = head;
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}
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last_read = this_read;
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if (old != head)
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samples++;
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size = head - old;
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if ((old & md->mask) + size != (head & md->mask)) {
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buf = &data[old & md->mask];
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size = md->mask + 1 - (old & md->mask);
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old += size;
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while (size) {
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int ret = write(output, buf, size);
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if (ret < 0)
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die("failed to write");
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size -= ret;
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buf += ret;
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bytes_written += ret;
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}
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}
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buf = &data[old & md->mask];
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size = head - old;
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old += size;
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while (size) {
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int ret = write(output, buf, size);
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if (ret < 0)
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die("failed to write");
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size -= ret;
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buf += ret;
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bytes_written += ret;
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}
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md->prev = old;
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}
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static volatile int done = 0;
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static volatile int signr = -1;
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static void sig_handler(int sig)
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{
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done = 1;
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signr = sig;
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}
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static void sig_atexit(void)
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{
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if (signr == -1)
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return;
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signal(signr, SIG_DFL);
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kill(getpid(), signr);
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}
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static void pid_synthesize_comm_event(pid_t pid, int full)
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{
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struct comm_event comm_ev;
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char filename[PATH_MAX];
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char bf[BUFSIZ];
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int fd, ret;
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size_t size;
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char *field, *sep;
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DIR *tasks;
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struct dirent dirent, *next;
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snprintf(filename, sizeof(filename), "/proc/%d/stat", pid);
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fd = open(filename, O_RDONLY);
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if (fd < 0) {
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fprintf(stderr, "couldn't open %s\n", filename);
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exit(EXIT_FAILURE);
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}
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if (read(fd, bf, sizeof(bf)) < 0) {
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fprintf(stderr, "couldn't read %s\n", filename);
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exit(EXIT_FAILURE);
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}
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close(fd);
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/* 9027 (cat) R 6747 9027 6747 34816 9027 ... */
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memset(&comm_ev, 0, sizeof(comm_ev));
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field = strchr(bf, '(');
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if (field == NULL)
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goto out_failure;
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sep = strchr(++field, ')');
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if (sep == NULL)
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goto out_failure;
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size = sep - field;
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memcpy(comm_ev.comm, field, size++);
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comm_ev.pid = pid;
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comm_ev.header.type = PERF_EVENT_COMM;
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size = ALIGN(size, sizeof(__u64));
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comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
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if (!full) {
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comm_ev.tid = pid;
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ret = write(output, &comm_ev, comm_ev.header.size);
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if (ret < 0) {
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perror("failed to write");
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exit(-1);
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}
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return;
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}
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snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
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tasks = opendir(filename);
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while (!readdir_r(tasks, &dirent, &next) && next) {
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char *end;
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pid = strtol(dirent.d_name, &end, 10);
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if (*end)
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continue;
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comm_ev.tid = pid;
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ret = write(output, &comm_ev, comm_ev.header.size);
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if (ret < 0) {
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perror("failed to write");
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exit(-1);
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}
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}
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closedir(tasks);
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return;
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out_failure:
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fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
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filename);
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exit(EXIT_FAILURE);
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}
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static void pid_synthesize_mmap_samples(pid_t pid)
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{
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char filename[PATH_MAX];
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FILE *fp;
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snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
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fp = fopen(filename, "r");
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if (fp == NULL) {
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fprintf(stderr, "couldn't open %s\n", filename);
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exit(EXIT_FAILURE);
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}
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while (1) {
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char bf[BUFSIZ], *pbf = bf;
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struct mmap_event mmap_ev = {
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.header.type = PERF_EVENT_MMAP,
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};
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int n;
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size_t size;
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if (fgets(bf, sizeof(bf), fp) == NULL)
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break;
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/* 00400000-0040c000 r-xp 00000000 fd:01 41038 /bin/cat */
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n = hex2u64(pbf, &mmap_ev.start);
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if (n < 0)
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continue;
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pbf += n + 1;
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n = hex2u64(pbf, &mmap_ev.len);
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if (n < 0)
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continue;
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pbf += n + 3;
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if (*pbf == 'x') { /* vm_exec */
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char *execname = strrchr(bf, ' ');
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if (execname == NULL || execname[1] != '/')
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continue;
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execname += 1;
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size = strlen(execname);
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execname[size - 1] = '\0'; /* Remove \n */
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memcpy(mmap_ev.filename, execname, size);
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size = ALIGN(size, sizeof(__u64));
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mmap_ev.len -= mmap_ev.start;
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mmap_ev.header.size = (sizeof(mmap_ev) -
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(sizeof(mmap_ev.filename) - size));
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mmap_ev.pid = pid;
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mmap_ev.tid = pid;
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if (write(output, &mmap_ev, mmap_ev.header.size) < 0) {
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perror("failed to write");
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exit(-1);
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}
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}
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}
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fclose(fp);
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}
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static void synthesize_samples(void)
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{
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DIR *proc;
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struct dirent dirent, *next;
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proc = opendir("/proc");
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while (!readdir_r(proc, &dirent, &next) && next) {
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char *end;
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pid_t pid;
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pid = strtol(dirent.d_name, &end, 10);
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if (*end) /* only interested in proper numerical dirents */
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continue;
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pid_synthesize_comm_event(pid, 1);
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pid_synthesize_mmap_samples(pid);
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}
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closedir(proc);
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}
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static int group_fd;
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static void create_counter(int counter, int cpu, pid_t pid)
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{
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struct perf_counter_attr *attr = attrs + counter;
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int track = 1;
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attr->sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
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if (freq) {
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attr->sample_type |= PERF_SAMPLE_PERIOD;
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attr->freq = 1;
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attr->sample_freq = freq;
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}
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attr->mmap = track;
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attr->comm = track;
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attr->inherit = (cpu < 0) && inherit;
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attr->disabled = 1;
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track = 0; /* only the first counter needs these */
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try_again:
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fd[nr_cpu][counter] = sys_perf_counter_open(attr, pid, cpu, group_fd, 0);
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if (fd[nr_cpu][counter] < 0) {
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int err = errno;
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if (err == EPERM)
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die("Permission error - are you root?\n");
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/*
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* If it's cycles then fall back to hrtimer
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* based cpu-clock-tick sw counter, which
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* is always available even if no PMU support:
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*/
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if (attr->type == PERF_TYPE_HARDWARE
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&& attr->config == PERF_COUNT_HW_CPU_CYCLES) {
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if (verbose)
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warning(" ... trying to fall back to cpu-clock-ticks\n");
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attr->type = PERF_TYPE_SOFTWARE;
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attr->config = PERF_COUNT_SW_CPU_CLOCK;
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goto try_again;
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}
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printf("\n");
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error("perfcounter syscall returned with %d (%s)\n",
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fd[nr_cpu][counter], strerror(err));
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die("No CONFIG_PERF_COUNTERS=y kernel support configured?\n");
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exit(-1);
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}
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assert(fd[nr_cpu][counter] >= 0);
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fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
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/*
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* First counter acts as the group leader:
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*/
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if (group && group_fd == -1)
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group_fd = fd[nr_cpu][counter];
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event_array[nr_poll].fd = fd[nr_cpu][counter];
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event_array[nr_poll].events = POLLIN;
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nr_poll++;
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mmap_array[nr_cpu][counter].counter = counter;
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mmap_array[nr_cpu][counter].prev = 0;
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mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
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mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
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PROT_READ, MAP_SHARED, fd[nr_cpu][counter], 0);
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if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
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error("failed to mmap with %d (%s)\n", errno, strerror(errno));
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exit(-1);
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}
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ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
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}
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static void open_counters(int cpu, pid_t pid)
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{
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int counter;
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if (pid > 0) {
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pid_synthesize_comm_event(pid, 0);
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pid_synthesize_mmap_samples(pid);
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}
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group_fd = -1;
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for (counter = 0; counter < nr_counters; counter++)
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create_counter(counter, cpu, pid);
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nr_cpu++;
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}
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static int __cmd_record(int argc, const char **argv)
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{
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int i, counter;
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struct stat st;
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pid_t pid;
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int flags;
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int ret;
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page_size = sysconf(_SC_PAGE_SIZE);
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nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
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assert(nr_cpus <= MAX_NR_CPUS);
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assert(nr_cpus >= 0);
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if (!stat(output_name, &st) && !force && !append_file) {
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fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
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output_name);
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exit(-1);
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}
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flags = O_CREAT|O_RDWR;
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if (append_file)
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flags |= O_APPEND;
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else
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flags |= O_TRUNC;
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output = open(output_name, flags, S_IRUSR|S_IWUSR);
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if (output < 0) {
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perror("failed to create output file");
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exit(-1);
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}
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if (!system_wide) {
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open_counters(-1, target_pid != -1 ? target_pid : getpid());
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} else for (i = 0; i < nr_cpus; i++)
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open_counters(i, target_pid);
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atexit(sig_atexit);
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signal(SIGCHLD, sig_handler);
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signal(SIGINT, sig_handler);
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if (target_pid == -1 && argc) {
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pid = fork();
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if (pid < 0)
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perror("failed to fork");
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if (!pid) {
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if (execvp(argv[0], (char **)argv)) {
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perror(argv[0]);
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exit(-1);
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}
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}
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}
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if (realtime_prio) {
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struct sched_param param;
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param.sched_priority = realtime_prio;
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if (sched_setscheduler(0, SCHED_FIFO, ¶m)) {
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printf("Could not set realtime priority.\n");
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exit(-1);
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}
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}
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if (system_wide)
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synthesize_samples();
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while (!done) {
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int hits = samples;
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for (i = 0; i < nr_cpu; i++) {
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for (counter = 0; counter < nr_counters; counter++)
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mmap_read(&mmap_array[i][counter]);
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}
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if (hits == samples)
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ret = poll(event_array, nr_poll, 100);
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}
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/*
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* Approximate RIP event size: 24 bytes.
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*/
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fprintf(stderr,
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"[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
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(double)bytes_written / 1024.0 / 1024.0,
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output_name,
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bytes_written / 24);
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return 0;
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}
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static const char * const record_usage[] = {
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"perf record [<options>] [<command>]",
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"perf record [<options>] -- <command> [<options>]",
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NULL
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};
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static const struct option options[] = {
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OPT_CALLBACK('e', "event", NULL, "event",
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"event selector. use 'perf list' to list available events",
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parse_events),
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OPT_INTEGER('p', "pid", &target_pid,
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"record events on existing pid"),
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OPT_INTEGER('r', "realtime", &realtime_prio,
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"collect data with this RT SCHED_FIFO priority"),
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OPT_BOOLEAN('a', "all-cpus", &system_wide,
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"system-wide collection from all CPUs"),
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OPT_BOOLEAN('A', "append", &append_file,
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"append to the output file to do incremental profiling"),
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OPT_BOOLEAN('f', "force", &force,
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"overwrite existing data file"),
|
|
OPT_LONG('c', "count", &default_interval,
|
|
"event period to sample"),
|
|
OPT_STRING('o', "output", &output_name, "file",
|
|
"output file name"),
|
|
OPT_BOOLEAN('i', "inherit", &inherit,
|
|
"child tasks inherit counters"),
|
|
OPT_INTEGER('F', "freq", &freq,
|
|
"profile at this frequency"),
|
|
OPT_INTEGER('m', "mmap-pages", &mmap_pages,
|
|
"number of mmap data pages"),
|
|
OPT_BOOLEAN('v', "verbose", &verbose,
|
|
"be more verbose (show counter open errors, etc)"),
|
|
OPT_END()
|
|
};
|
|
|
|
int cmd_record(int argc, const char **argv, const char *prefix)
|
|
{
|
|
int counter;
|
|
|
|
argc = parse_options(argc, argv, options, record_usage, 0);
|
|
if (!argc && target_pid == -1 && !system_wide)
|
|
usage_with_options(record_usage, options);
|
|
|
|
if (!nr_counters) {
|
|
nr_counters = 1;
|
|
attrs[0].type = PERF_TYPE_HARDWARE;
|
|
attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
|
|
}
|
|
|
|
for (counter = 0; counter < nr_counters; counter++) {
|
|
if (attrs[counter].sample_period)
|
|
continue;
|
|
|
|
attrs[counter].sample_period = default_interval;
|
|
}
|
|
|
|
return __cmd_record(argc, argv);
|
|
}
|