Re: [libvirt] [PATCHv3] Add util virCgroupGetBlkioIo*Serviced methods.

This reads blkio stats from blkio.throttle.io_service_bytes and blkio.throttle.io_serviced. --- Note on v3: - rebased to current master, sadly the virCgroupSetBlkioDeviceReadBps etc conflicted src/libvirt_private.syms | 2 + src/util/vircgroup.c | 242 +++++++++++++++++++++++++++++++++++++++++++++++ src/util/vircgroup.h | 12 +++ 3 files changed, 256 insertions(+) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 3ede3d5..1e44ed8 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1002,6 +1002,8 @@ virCgroupDenyDevice; virCgroupDenyDeviceMajor; virCgroupDenyDevicePath; virCgroupFree; +virCgroupGetBlkioIoDeviceServiced; +virCgroupGetBlkioIoServiced; virCgroupGetBlkioWeight; virCgroupGetCpuacctPercpuUsage; virCgroupGetCpuacctStat; diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c index a6d60c5..2b70bcb 100644 --- a/src/util/vircgroup.c +++ b/src/util/vircgroup.c @@ -1786,6 +1786,221 @@ virCgroupPathOfController(virCgroupPtr group, /** + * virCgroupGetBlkioIoServiced: + * + * @group: The cgroup to get throughput for + * @bytes_read: Pointer to returned bytes read + * @bytes_write: Pointer to returned bytes written + * @requests_read: Pointer to returned read io ops + * @requests_write: Pointer to returned write io ops + * + * Returns: 0 on success, -1 on error + */ +int +virCgroupGetBlkioIoServiced(virCgroupPtr group, + long long *bytes_read, + long long *bytes_write, + long long *requests_read, + long long *requests_write) +{ + long long stats_val; + char *str1 = NULL, *str2 = NULL, *p1, *p2; + size_t i; + int ret = -1; + + const char *value_names[] = { + "Read ", + "Write " + }; + long long *bytes_ptrs[] = { + bytes_read, + bytes_write + }; + long long *requests_ptrs[] = { + requests_read, + requests_write + }; + + *bytes_read = 0; + *bytes_write = 0; + *requests_read = 0; + *requests_write = 0; + + if (virCgroupGetValueStr(group, + VIR_CGROUP_CONTROLLER_BLKIO, + "blkio.throttle.io_service_bytes", &str1) < 0) + goto cleanup; + + if (virCgroupGetValueStr(group, + VIR_CGROUP_CONTROLLER_BLKIO, + "blkio.throttle.io_serviced", &str2) < 0) + goto cleanup; + + /* sum up all entries of the same kind, from all devices */ + for (i = 0; i < ARRAY_CARDINALITY(value_names); i++) { + p1 = str1; + p2 = str2; + + while ((p1 = strstr(p1, value_names[i]))) { + p1 += strlen(value_names[i]); + if (virStrToLong_ll(p1, &p1, 10, &stats_val) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Cannot parse byte %sstat '%s'"), + value_names[i], + p1); + goto cleanup; + } + + if (stats_val < 0 || + (stats_val > 0 && *bytes_ptrs[i] > (LLONG_MAX - stats_val))) + { + virReportError(VIR_ERR_OVERFLOW, + _("Sum of byte %sstat overflows"), + value_names[i]); + goto cleanup; + } + *bytes_ptrs[i] += stats_val; + } + + while ((p2 = strstr(p2, value_names[i]))) { + p2 += strlen(value_names[i]); + if (virStrToLong_ll(p2, &p2, 10, &stats_val) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Cannot parse %srequest stat '%s'"), + value_names[i], + p2); + goto cleanup; + } + + if (stats_val < 0 || + (stats_val > 0 && *requests_ptrs[i] > (LLONG_MAX - stats_val))) + { + virReportError(VIR_ERR_OVERFLOW, + _("Sum of %srequest stat overflows"), + value_names[i]); + goto cleanup; + } + *requests_ptrs[i] += stats_val; + } + } + + ret = 0; + +cleanup: + VIR_FREE(str2); + VIR_FREE(str1); + return ret; +} + + +/** + * virCgroupGetBlkioIoDeviceServiced: + * + * @group: The cgroup to get throughput for + * @path: The device to get throughput for + * @bytes_read: Pointer to returned bytes read + * @bytes_write: Pointer to returned bytes written + * @requests_read: Pointer to returned read io ops + * @requests_write: Pointer to returned write io ops + * + * Returns: 0 on success, -1 on error + */ +int +virCgroupGetBlkioIoDeviceServiced(virCgroupPtr group, + const char *path, + long long *bytes_read, + long long *bytes_write, + long long *requests_read, + long long *requests_write) +{ + char *str1 = NULL, *str2 = NULL, *str3 = NULL, *p; + struct stat sb; + size_t i; + int ret = -1; + + const char *value_names[] = { + "Read ", + "Write " + }; + long long *bytes_ptrs[] = { + bytes_read, + bytes_write + }; + long long *requests_ptrs[] = { + requests_read, + requests_write + }; + + if (stat(path, &sb) < 0) { + virReportSystemError(errno, + _("Path '%s' is not accessible"), + path); + return -1; + } + + if (!S_ISBLK(sb.st_mode)) { + virReportSystemError(EINVAL, + _("Path '%s' must be a block device"), + path); + return -1; + } + + if (virCgroupGetValueStr(group, + VIR_CGROUP_CONTROLLER_BLKIO, + "blkio.throttle.io_service_bytes", &str1) < 0) + goto cleanup; + + if (virCgroupGetValueStr(group, + VIR_CGROUP_CONTROLLER_BLKIO, + "blkio.throttle.io_serviced", &str2) < 0) + goto cleanup; + + if (virAsprintf(&str3, "%d:%d ", major(sb.st_rdev), minor(sb.st_rdev)) < 0) + goto cleanup; + + if (!(p = strstr(str1, str3))) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Cannot find byte stats for block device '%s'"), + p);

+ goto cleanup; + } + + if (!(p = strstr(str2, str3))) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Cannot find request stats for block device '%s'"), + p);

+ goto cleanup; + } + + for (i = 0; i < ARRAY_CARDINALITY(value_names); i++) { + if (!(p = strstr(p, value_names[i])) || + virStrToLong_ll(p + strlen(value_names[i]), &p, 10, bytes_ptrs[i]) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Cannot parse stat '%s'"), + p + strlen(value_names[i]));

+ goto cleanup; + } + + if (!(p = strstr(p, value_names[i])) || + virStrToLong_ll(p + strlen(value_names[i]), &p, 10, requests_ptrs[i]) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Cannot parse stat '%s'"), + p + strlen(value_names[i]));