From: Arnaldo Carvalho de Melo Date: Fri, 15 May 2009 01:50:46 +0000 (-0300) Subject: perf record: Allow specifying a pid to record X-Git-Tag: v2.6.31-rc1~383^2~282 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1a853e36871b533ccc3f3c5bdd5cd0d867043a00;p=platform%2Fkernel%2Flinux-3.10.git perf record: Allow specifying a pid to record Allow specifying a pid instead of always fork+exec'ing a command. Because the PERF_EVENT_COMM and PERF_EVENT_MMAP events happened before we connected, we must synthesize them so that 'perf report' can get what it needs. [ Impact: add new command line option ] Signed-off-by: Arnaldo Carvalho de Melo Cc: Clark Williams Cc: John Kacur Cc: Peter Zijlstra LKML-Reference: <20090515015046.GA13664@ghostprotocols.net> Signed-off-by: Ingo Molnar --- diff --git a/Documentation/perf_counter/builtin-record.c b/Documentation/perf_counter/builtin-record.c index 5f5e6df..efb8759 100644 --- a/Documentation/perf_counter/builtin-record.c +++ b/Documentation/perf_counter/builtin-record.c @@ -34,6 +34,9 @@ #include "perf.h" +#define ALIGN(x,a) __ALIGN_MASK(x,(typeof(x))(a)-1) +#define __ALIGN_MASK(x,mask) (((x)+(mask))&~(mask)) + static int nr_counters = 0; static __u64 event_id[MAX_COUNTERS] = { }; static int default_interval = 100000; @@ -47,6 +50,7 @@ static char *output_name = "output.perf"; static int group = 0; static unsigned int realtime_prio = 0; static int system_wide = 0; +static pid_t target_pid = -1; static int inherit = 1; static int nmi = 1; @@ -180,6 +184,7 @@ static void display_help(void) " -c CNT --count=CNT # event period to sample\n" " -m pages --mmap_pages= # number of mmap data pages\n" " -o file --output= # output file\n" + " -p pid --pid= # record events on existing pid\n" " -r prio --realtime= # use RT prio\n" " -s --system # system wide profiling\n" ); @@ -199,13 +204,14 @@ static void process_options(int argc, const char *argv[]) {"event", required_argument, NULL, 'e'}, {"mmap_pages", required_argument, NULL, 'm'}, {"output", required_argument, NULL, 'o'}, + {"pid", required_argument, NULL, 'p'}, {"realtime", required_argument, NULL, 'r'}, {"system", no_argument, NULL, 's'}, {"inherit", no_argument, NULL, 'i'}, {"nmi", no_argument, NULL, 'n'}, {NULL, 0, NULL, 0 } }; - int c = getopt_long(argc, argv, "+:c:e:m:o:r:sin", + int c = getopt_long(argc, argv, "+:c:e:m:o:p:r:sin", long_options, &option_index); if (c == -1) break; @@ -215,6 +221,7 @@ static void process_options(int argc, const char *argv[]) case 'e': error = parse_events(optarg); break; case 'm': mmap_pages = atoi(optarg); break; case 'o': output_name = strdup(optarg); break; + case 'p': target_pid = atoi(optarg); break; case 'r': realtime_prio = atoi(optarg); break; case 's': system_wide ^= 1; break; case 'i': inherit ^= 1; break; @@ -223,7 +230,7 @@ static void process_options(int argc, const char *argv[]) } } - if (argc - optind == 0) + if (argc - optind == 0 && target_pid == -1) error = 1; if (error) @@ -350,15 +357,135 @@ static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS]; static int nr_poll; static int nr_cpu; -static void open_counters(int cpu) +struct mmap_event { + struct perf_event_header header; + __u32 pid, tid; + __u64 start; + __u64 len; + __u64 pgoff; + char filename[PATH_MAX]; +}; +struct comm_event { + struct perf_event_header header; + __u32 pid,tid; + char comm[16]; +}; + +static pid_t pid_synthesize_comm_event(pid_t pid) +{ + char filename[PATH_MAX]; + char bf[BUFSIZ]; + struct comm_event comm_ev; + size_t size; + int fd; + + snprintf(filename, sizeof(filename), "/proc/%d/stat", pid); + + fd = open(filename, O_RDONLY); + if (fd < 0) { + fprintf(stderr, "couldn't open %s\n", filename); + exit(EXIT_FAILURE); + } + if (read(fd, bf, sizeof(bf)) < 0) { + fprintf(stderr, "couldn't read %s\n", filename); + exit(EXIT_FAILURE); + } + close(fd); + + pid_t spid, ppid; + char state; + char comm[18]; + + memset(&comm_ev, 0, sizeof(comm_ev)); + int nr = sscanf(bf, "%d %s %c %d %d ", + &spid, comm, &state, &ppid, &comm_ev.pid); + if (nr != 5) { + fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n", + filename); + exit(EXIT_FAILURE); + } + comm_ev.header.type = PERF_EVENT_COMM; + comm_ev.tid = pid; + size = strlen(comm); + comm[--size] = '\0'; /* Remove the ')' at the end */ + --size; /* Remove the '(' at the begin */ + memcpy(comm_ev.comm, comm + 1, size); + size = ALIGN(size, sizeof(uint64_t)); + comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size); + int ret = write(output, &comm_ev, comm_ev.header.size); + if (ret < 0) { + perror("failed to write"); + exit(-1); + } + return comm_ev.pid; +} + +static void pid_synthesize_mmap_events(pid_t pid, pid_t pgid) +{ + char filename[PATH_MAX]; + FILE *fp; + + snprintf(filename, sizeof(filename), "/proc/%d/maps", pid); + + fp = fopen(filename, "r"); + if (fp == NULL) { + fprintf(stderr, "couldn't open %s\n", filename); + exit(EXIT_FAILURE); + } + while (1) { + char bf[BUFSIZ]; + unsigned char vm_read, vm_write, vm_exec, vm_mayshare; + struct mmap_event mmap_ev = { + .header.type = PERF_EVENT_MMAP, + }; + unsigned long ino; + int major, minor; + size_t size; + if (fgets(bf, sizeof(bf), fp) == NULL) + break; + + /* 00400000-0040c000 r-xp 00000000 fd:01 41038 /bin/cat */ + sscanf(bf, "%llx-%llx %c%c%c%c %llx %x:%x %lu", + &mmap_ev.start, &mmap_ev.len, + &vm_read, &vm_write, &vm_exec, &vm_mayshare, + &mmap_ev.pgoff, &major, &minor, &ino); + if (vm_exec == 'x') { + char *execname = strrchr(bf, ' '); + + if (execname == NULL || execname[1] != '/') + continue; + + execname += 1; + size = strlen(execname); + execname[size - 1] = '\0'; /* Remove \n */ + memcpy(mmap_ev.filename, execname, size); + size = ALIGN(size, sizeof(uint64_t)); + mmap_ev.len -= mmap_ev.start; + mmap_ev.header.size = (sizeof(mmap_ev) - + (sizeof(mmap_ev.filename) - size)); + mmap_ev.pid = pgid; + mmap_ev.tid = pid; + + if (write(output, &mmap_ev, mmap_ev.header.size) < 0) { + perror("failed to write"); + exit(-1); + } + } + } + + fclose(fp); +} + +static void open_counters(int cpu, pid_t pid) { struct perf_counter_hw_event hw_event; int counter, group_fd; int track = 1; - pid_t pid = -1; - if (cpu < 0) - pid = 0; + if (pid > 0) { + pid_t pgid = pid_synthesize_comm_event(pid); + pid_synthesize_mmap_events(pid, pgid); + } group_fd = -1; for (counter = 0; counter < nr_counters; counter++) { @@ -435,22 +562,24 @@ int cmd_record(int argc, const char **argv) argc -= optind; argv += optind; - if (!system_wide) - open_counters(-1); - else for (i = 0; i < nr_cpus; i++) - open_counters(i); + if (!system_wide) { + open_counters(-1, target_pid != -1 ? target_pid : 0); + } else for (i = 0; i < nr_cpus; i++) + open_counters(i, target_pid); signal(SIGCHLD, sig_handler); signal(SIGINT, sig_handler); - pid = fork(); - if (pid < 0) - perror("failed to fork"); + if (target_pid == -1) { + pid = fork(); + if (pid < 0) + perror("failed to fork"); - if (!pid) { - if (execvp(argv[0], argv)) { - perror(argv[0]); - exit(-1); + if (!pid) { + if (execvp(argv[0], argv)) { + perror(argv[0]); + exit(-1); + } } }