| Message ID | 20190222142836.12596-7-tstoyanov@vmware.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | trace-cmd: Timetamps sync between host and guest machines, relying on vsock events. | expand |
On Fri, Feb 22, 2019 at 04:28:35PM +0200, Tzvetomir Stoyanov wrote: > In order to match host and guest events, a mapping between guest VCPU > and the host task, running this VCPU is needed. Extended existing > struct guest to hold such mapping and added logic in read_qemu_guests() > function to initialize it. Implemented a new internal API, > get_guest_vcpu_pids(), to retrieve VCPU-task mapping for given VM. > > Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com> > --- > tracecmd/include/trace-local.h | 3 ++ > tracecmd/trace-record.c | 57 +++++++++++++++++++++++++++++++++- > 2 files changed, 59 insertions(+), 1 deletion(-) > > diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h > index d7bdb1f..ef6848f 100644 > --- a/tracecmd/include/trace-local.h > +++ b/tracecmd/include/trace-local.h > @@ -236,6 +236,9 @@ void show_instance_file(struct buffer_instance *instance, const char *name); > > int count_cpus(void); > > +#define VCPUS_MAX 256 Is VCPUS_MAX intended to be used somewhere outside of trace-record.c? If not, I think we should keep it there locally and not expose it. > +int *get_guest_vcpu_pids(int cid); > + > /* No longer in event-utils.h */ > void __noreturn die(const char *fmt, ...); /* Can be overriden */ > void *malloc_or_die(unsigned int size); /* Can be overridden */ > diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c > index c57ed6b..59f0197 100644 > --- a/tracecmd/trace-record.c > +++ b/tracecmd/trace-record.c > @@ -2752,6 +2752,7 @@ struct guest { > char *name; > int cid; > int pid; > + int cpu_pid[VCPUS_MAX]; > }; > > static struct guest *guests; > @@ -2772,9 +2773,10 @@ static char *get_qemu_guest_name(char *arg) > static void read_qemu_guests(void) > { > static bool initialized; > + struct dirent *entry_t; > struct dirent *entry; > char path[PATH_MAX]; > - DIR *dir; > + DIR *dir, *dir_t; > > if (initialized) > return; > @@ -2830,6 +2832,49 @@ static void read_qemu_guests(void) > if (!is_qemu) > goto next; > I think the following section should go into separate function since this one is already getting too long. Then here we can just do: read_qemu_guest_vcpus(&guest); Where read_qemu_guest_vcpus can be something like that: static void read_qemu_guest_vcpus(struct guest *guest) { struct dirent *entry; char path[PATH_MAX]; size_t buf_len = 0; char *buf = NULL; int vcpu; DIR *dir; FILE *f; snprintf(path, sizeof(path), "/proc/%d/task", guest->pid); dir = opendir(path); if (!dir) return; for (entry = readdir(dir); entry; entry = readdir(dir)) { if (!(entry->d_type == DT_DIR && is_digits(entry->d_name))) continue; snprintf(path, sizeof(path), "/proc/%d/task/%s/comm", guest->pid, entry->d_name); f = fopen(path, "r"); if (!f) continue; if (getline(&buf, &buf_len, f) < 0) goto next; if (strncmp(buf, "CPU ", 4) != 0) goto next; vcpu = atoi(buf + 4); if (!(vcpu >= 0 && vcpu < VCPUS_MAX)) goto next; guest->cpu_pid[vcpu] = atoi(entry->d_name); next: fclose(f); } free(buf); } Thank you, -- Slavi > + snprintf(path, sizeof(path), "/proc/%s/task", entry->d_name); > + dir_t = opendir(path); > + if (dir_t) { > + unsigned int vcpu; > + char *buf = NULL; > + char *cpu_str; > + FILE *ft; > + size_t n; > + int j; > + > + for (entry_t = readdir(dir_t); entry_t; entry_t = readdir(dir_t)) { > + if (!(entry_t->d_type == DT_DIR && > + is_digits(entry_t->d_name))) > + continue; > + snprintf(path, sizeof(path), > + "/proc/%s/task/%s/comm", > + entry->d_name, entry_t->d_name); > + ft = fopen(path, "r"); > + if (!ft) > + continue; > + getline(&buf, &n, ft); > + if (buf && strncmp(buf, "CPU ", 4) == 0) { > + cpu_str = buf; > + while (*cpu_str != '\0' && > + isdigit(*cpu_str) == 0) > + cpu_str++; > + if (*cpu_str != '\0') { > + j = 0; > + while (cpu_str[j] != '\0' && > + isdigit(cpu_str[j]) != 0) > + j++; > + cpu_str[j] = '\0'; > + vcpu = atoi(cpu_str); > + if (vcpu < VCPUS_MAX) > + guest.cpu_pid[vcpu] = atoi(entry_t->d_name); > + } > + } > + free(buf); > + fclose(ft); > + buf = NULL; > + } > + } > + > guests = realloc(guests, (guests_len + 1) * sizeof(*guests)); > if (!guests) > die("Can not allocate guest buffer"); > @@ -2875,6 +2920,16 @@ static char *parse_guest_name(char *guest, int *cid, int *port) > return guest; > } > > +int *get_guest_vcpu_pids(int cid) > +{ > + int i; > + > + for (i = 0; i < guests_len; i++) > + if (cid == guests[i].cid) > + return guests[i].cpu_pid; > + return NULL; > +} > + > static void set_prio(int prio) > { > struct sched_param sp; > -- > 2.20.1 >
On Fri, 22 Feb 2019 19:07:09 +0200 Slavomir Kaslev <kaslevs@vmware.com> wrote: > I think the following section should go into separate function since this one is > already getting too long. Then here we can just do: Thanks for reviewing these Slavomir. Tvzetomir, can you update the patch series and send out a new version with these updates when you get a chance. Thanks! -- Steve
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h index d7bdb1f..ef6848f 100644 --- a/tracecmd/include/trace-local.h +++ b/tracecmd/include/trace-local.h @@ -236,6 +236,9 @@ void show_instance_file(struct buffer_instance *instance, const char *name); int count_cpus(void); +#define VCPUS_MAX 256 +int *get_guest_vcpu_pids(int cid); + /* No longer in event-utils.h */ void __noreturn die(const char *fmt, ...); /* Can be overriden */ void *malloc_or_die(unsigned int size); /* Can be overridden */ diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c index c57ed6b..59f0197 100644 --- a/tracecmd/trace-record.c +++ b/tracecmd/trace-record.c @@ -2752,6 +2752,7 @@ struct guest { char *name; int cid; int pid; + int cpu_pid[VCPUS_MAX]; }; static struct guest *guests; @@ -2772,9 +2773,10 @@ static char *get_qemu_guest_name(char *arg) static void read_qemu_guests(void) { static bool initialized; + struct dirent *entry_t; struct dirent *entry; char path[PATH_MAX]; - DIR *dir; + DIR *dir, *dir_t; if (initialized) return; @@ -2830,6 +2832,49 @@ static void read_qemu_guests(void) if (!is_qemu) goto next; + snprintf(path, sizeof(path), "/proc/%s/task", entry->d_name); + dir_t = opendir(path); + if (dir_t) { + unsigned int vcpu; + char *buf = NULL; + char *cpu_str; + FILE *ft; + size_t n; + int j; + + for (entry_t = readdir(dir_t); entry_t; entry_t = readdir(dir_t)) { + if (!(entry_t->d_type == DT_DIR && + is_digits(entry_t->d_name))) + continue; + snprintf(path, sizeof(path), + "/proc/%s/task/%s/comm", + entry->d_name, entry_t->d_name); + ft = fopen(path, "r"); + if (!ft) + continue; + getline(&buf, &n, ft); + if (buf && strncmp(buf, "CPU ", 4) == 0) { + cpu_str = buf; + while (*cpu_str != '\0' && + isdigit(*cpu_str) == 0) + cpu_str++; + if (*cpu_str != '\0') { + j = 0; + while (cpu_str[j] != '\0' && + isdigit(cpu_str[j]) != 0) + j++; + cpu_str[j] = '\0'; + vcpu = atoi(cpu_str); + if (vcpu < VCPUS_MAX) + guest.cpu_pid[vcpu] = atoi(entry_t->d_name); + } + } + free(buf); + fclose(ft); + buf = NULL; + } + } + guests = realloc(guests, (guests_len + 1) * sizeof(*guests)); if (!guests) die("Can not allocate guest buffer"); @@ -2875,6 +2920,16 @@ static char *parse_guest_name(char *guest, int *cid, int *port) return guest; } +int *get_guest_vcpu_pids(int cid) +{ + int i; + + for (i = 0; i < guests_len; i++) + if (cid == guests[i].cid) + return guests[i].cpu_pid; + return NULL; +} + static void set_prio(int prio) { struct sched_param sp;
In order to match host and guest events, a mapping between guest VCPU and the host task, running this VCPU is needed. Extended existing struct guest to hold such mapping and added logic in read_qemu_guests() function to initialize it. Implemented a new internal API, get_guest_vcpu_pids(), to retrieve VCPU-task mapping for given VM. Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com> --- tracecmd/include/trace-local.h | 3 ++ tracecmd/trace-record.c | 57 +++++++++++++++++++++++++++++++++- 2 files changed, 59 insertions(+), 1 deletion(-)