| Message ID | 20200302101404.150035-2-tz.stoyanov@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Timestamp synchronization of host - guest tracing session | expand |
On Mon, 2 Mar 2020 12:13:52 +0200 "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote: > +static int read_qemu_guests_pids(char *guest_task, struct guest *guest) > +{ > + struct dirent *entry; > + char path[PATH_MAX]; > + char *buf = NULL; > + size_t n = 0; > + long vcpu; > + long pid; > + DIR *dir; > + FILE *f; int ret = 0; > + > + snprintf(path, sizeof(path), "/proc/%s/task", guest_task); > + dir = opendir(path); > + if (!dir) > + return -1; > + > + while ((entry = readdir(dir))) { while (!ret && (entry = readdir(dir)) { > + if (!(entry->d_type == DT_DIR && is_digits(entry->d_name))) > + continue; > + > + snprintf(path, sizeof(path), "/proc/%s/task/%s/comm", > + guest_task, entry->d_name); > + f = fopen(path, "r"); > + if (!f) > + continue; > + > + if (getline(&buf, &n, f) >= 0 && > + strncmp(buf, "CPU ", 4) == 0) { > + vcpu = strtol(buf + 4, NULL, 10); > + pid = strtol(entry->d_name, NULL, 10); > + if (vcpu < INT_MAX && pid < INT_MAX && > + vcpu >= 0 && pid >= 0) { > + if (set_vcpu_pid_mapping(guest, vcpu, pid)) > + return -1; > + } Perhaps this should error on else. Also, you don't want a return here, but instead, a break. if (...) { ret = -1; break; } > + } > + > + fclose(f); > + } > + free(buf); > + return 0; return ret; Otherwise you don't close the file descriptor and free buf. -- Steve > +} > + > static void read_qemu_guests(void) > { > static bool initialized; > @@ -3115,6 +3179,10 @@ static void read_qemu_guests(void) > if (!is_qemu) > goto next; > > + if (read_qemu_guests_pids(entry->d_name, &guest)) > + warning("Failed to retrieve VPCU - PID mapping for guest %s", > + guest.name ? guest.name : "Unknown"); > + > guests = realloc(guests, (guests_len + 1) * sizeof(*guests)); > if (!guests) > die("Can not allocate guest buffer"); > @@ -3160,6 +3228,22 @@ static char *parse_guest_name(char *guest, int *cid, int *port) > return guest; > } > > +int get_guest_vcpu_pid(unsigned int guest_cid, unsigned int guest_vcpu) > +{ > + int i; > + > + if (!guests) > + return -1; > + > + for (i = 0; i < guests_len; i++) { > + if (guests[i].cpu_pid < 0 || guest_vcpu >= guests[i].cpu_max) > + continue; > + if (guest_cid == guests[i].cid) > + return guests[i].cpu_pid[guest_vcpu]; > + } > + return -1; > +} > + > static void set_prio(int prio) > { > struct sched_param sp;
On Mon, 2 Mar 2020 12:13:52 +0200 "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote: > +static int set_vcpu_pid_mapping(struct guest *guest, int cpu, int pid) > +{ > + int *cpu_pid; > + int i; > + > + if (cpu >= guest->cpu_max) { > + cpu_pid = realloc(guest->cpu_pid, (cpu + 1) * sizeof(int)); > + if (!cpu_pid) > + return -1; > + /* Handle sparse CPU numbers */ > + for (i = guest->cpu_max; i < cpu; i++) > + guest->cpu_pid[i] = -1; That needs to be: cpu_pid[i] = -1; as realloc() may have freed guest->cpu_pid here. -- Steve > + guest->cpu_max = cpu + 1; > + guest->cpu_pid = cpu_pid; > + } > + guest->cpu_pid[cpu] = pid; > + return 0; > +}
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h index 29f27793..a5cf0640 100644 --- a/tracecmd/include/trace-local.h +++ b/tracecmd/include/trace-local.h @@ -247,6 +247,8 @@ void update_first_instance(struct buffer_instance *instance, int topt); void show_instance_file(struct buffer_instance *instance, const char *name); +int get_guest_vcpu_pid(unsigned int guest_cid, unsigned int guest_vcpu); + /* moved from trace-cmd.h */ void tracecmd_create_top_instance(char *name); void tracecmd_remove_instances(void); diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c index 0a3851ad..3cbc832c 100644 --- a/tracecmd/trace-record.c +++ b/tracecmd/trace-record.c @@ -3035,11 +3035,32 @@ struct guest { char *name; int cid; int pid; + int cpu_max; + int *cpu_pid; }; static struct guest *guests; static size_t guests_len; +static int set_vcpu_pid_mapping(struct guest *guest, int cpu, int pid) +{ + int *cpu_pid; + int i; + + if (cpu >= guest->cpu_max) { + cpu_pid = realloc(guest->cpu_pid, (cpu + 1) * sizeof(int)); + if (!cpu_pid) + return -1; + /* Handle sparse CPU numbers */ + for (i = guest->cpu_max; i < cpu; i++) + guest->cpu_pid[i] = -1; + guest->cpu_max = cpu + 1; + guest->cpu_pid = cpu_pid; + } + guest->cpu_pid[cpu] = pid; + return 0; +} + static char *get_qemu_guest_name(char *arg) { char *tok, *end = arg; @@ -3052,6 +3073,49 @@ static char *get_qemu_guest_name(char *arg) return arg; } +static int read_qemu_guests_pids(char *guest_task, struct guest *guest) +{ + struct dirent *entry; + char path[PATH_MAX]; + char *buf = NULL; + size_t n = 0; + long vcpu; + long pid; + DIR *dir; + FILE *f; + + snprintf(path, sizeof(path), "/proc/%s/task", guest_task); + dir = opendir(path); + if (!dir) + return -1; + + while ((entry = readdir(dir))) { + if (!(entry->d_type == DT_DIR && is_digits(entry->d_name))) + continue; + + snprintf(path, sizeof(path), "/proc/%s/task/%s/comm", + guest_task, entry->d_name); + f = fopen(path, "r"); + if (!f) + continue; + + if (getline(&buf, &n, f) >= 0 && + strncmp(buf, "CPU ", 4) == 0) { + vcpu = strtol(buf + 4, NULL, 10); + pid = strtol(entry->d_name, NULL, 10); + if (vcpu < INT_MAX && pid < INT_MAX && + vcpu >= 0 && pid >= 0) { + if (set_vcpu_pid_mapping(guest, vcpu, pid)) + return -1; + } + } + + fclose(f); + } + free(buf); + return 0; +} + static void read_qemu_guests(void) { static bool initialized; @@ -3115,6 +3179,10 @@ static void read_qemu_guests(void) if (!is_qemu) goto next; + if (read_qemu_guests_pids(entry->d_name, &guest)) + warning("Failed to retrieve VPCU - PID mapping for guest %s", + guest.name ? guest.name : "Unknown"); + guests = realloc(guests, (guests_len + 1) * sizeof(*guests)); if (!guests) die("Can not allocate guest buffer"); @@ -3160,6 +3228,22 @@ static char *parse_guest_name(char *guest, int *cid, int *port) return guest; } +int get_guest_vcpu_pid(unsigned int guest_cid, unsigned int guest_vcpu) +{ + int i; + + if (!guests) + return -1; + + for (i = 0; i < guests_len; i++) { + if (guests[i].cpu_pid < 0 || guest_vcpu >= guests[i].cpu_max) + continue; + if (guest_cid == guests[i].cid) + return guests[i].cpu_pid[guest_vcpu]; + } + return -1; +} + static void set_prio(int prio) { struct sched_param sp;