10:18 p.m.
On Tue, Jul 10, 2012 at 05:13:15PM +0800, tangchen wrote:
Introduce a new API to move tasks of one controller from a cgroup to
another cgroup
Signed-off-by: Wen Congyang <wency(a)cn.fujitsu.com>
---
src/libvirt_private.syms | 2 +
src/util/cgroup.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++
src/util/cgroup.h | 8 +++
3 files changed, 137 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 8925267..812cf1d 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -60,6 +60,7 @@ virCapabilitiesSetMacPrefix;
# cgroup.h
virCgroupAddTask;
+virCgroupAddTaskController;
virCgroupAllowDeviceMajor;
virCgroupAllowDevicePath;
virCgroupControllerTypeFromString;
@@ -88,6 +89,7 @@ virCgroupKill;
virCgroupKillPainfully;
virCgroupKillRecursive;
virCgroupMounted;
+virCgroupMoveTask;
virCgroupPathOfController;
virCgroupRemove;
virCgroupSetBlkioDeviceWeight;
diff --git a/src/util/cgroup.c b/src/util/cgroup.c
index 1ac8278..3e9ba4e 100644
--- a/src/util/cgroup.c
+++ b/src/util/cgroup.c
@@ -791,6 +791,133 @@ int virCgroupAddTask(virCgroupPtr group, pid_t pid)
return rc;
}
+/**
+ * virCgroupAddTaskController:
+ *
+ * @group: The cgroup to add a task to
+ * @pid: The pid of the task to add
+ * @controller: The cgroup controller to be operated on
+ *
+ * Returns: 0 on success or -errno on failure
+ */
+int virCgroupAddTaskController(virCgroupPtr group, pid_t pid, int controller)
+{
+ int rc = 0;
unused variable.
+
+ if (controller < VIR_CGROUP_CONTROLLER_CPU ||
+ controller > VIR_CGROUP_CONTROLLER_BLKIO)
This can be improved by:
VIR_CGROUP_CONTROLLER_IS_VALID(controller)
+ return -EINVAL;
+
+ if (!group->controllers[controller].mountPoint)
+ return -EINVAL;
+
+ return virCgroupSetValueU64(group, controller, "tasks",
+ (unsigned long long)pid);
+}
+
+static int virCgroupAddTaskStr(virCgroupPtr group, const char *pidstr)
+{
+ unsigned long long value;
+
+ if (virStrToLong_ull(pidstr, NULL, 10, &value) < 0)
+ return -EINVAL;
+
+ return virCgroupAddTask(group, value);
+}
Unused static function can be removed harmlessly.
+
+static int virCgroupAddTaskStrController(virCgroupPtr group,
+ const char *pidstr,
+ int controller)
+{
+ char *str = NULL, *cur = NULL, *next = NULL;
+ unsigned long long pid = 0;
+ int len = 0, rc = 0;
+
+ len = strlen(pidstr);
+ VIR_ALLOC_N(str, len);
+ if (str == NULL) {
+ VIR_ERROR(_("No more memory."));
+ return -1;
+ }
+ rc = strcpy(str, pidstr);
+ if (rc != 0)
+ return rc;
virAsprintf
> +
> + cur = str;
> + while ((next = strchr(cur, '\n')) != NULL) {
> + *next = '\0';
> + rc = virStrToLong_ull(cur, NULL, 10, &pid);
> + if (rc != 0)
> + goto cleanup;
> + cur = next + 1;
> +
> + rc = virCgroupAddTaskController(group, pid, controller);
> + if (rc != 0)
> + goto cleanup;
> + }
> + if (cur != '\0') {
> + rc = virStrToLong_ull(cur, NULL, 10, &pid);
> + if (rc != 0)
> + goto cleanup;
> + rc = virCgroupAddTaskController(group, pid, controller);
> + if (rc != 0)
> + goto cleanup;
> + }
> +
> +cleanup:
> + VIR_FREE(str);
> + return rc;
> +}
> +
> +/**
> + * virCgroupMoveTask:
> + *
> + * @src_group: The source cgroup where all tasks are removed from
> + * @dest_group: The destination where all tasks are added to
> + * @controller: The cgroup controller to be operated on
> + *
> + * Returns: 0 on success or -errno on failure
> + */
> +int virCgroupMoveTask(virCgroupPtr src_group, virCgroupPtr dest_group,
> + int controller)
> +{
> + int rc = 0, err = 0;
> + char *content = NULL;
+
+ if (controller < VIR_CGROUP_CONTROLLER_CPU ||
+ controller > VIR_CGROUP_CONTROLLER_BLKIO)
> + return
-EINVAL;
> +
> + if (!src_group->controllers[controller].mountPoint ||
> + !dest_group->controllers[controller].mountPoint)
> + return -EINVAL;
> +
> + rc = virCgroupGetValueStr(src_group, controller, "tasks",
&content);
> + if (rc != 0)
> + return rc;
> +
> + rc = virCgroupAddTaskStrController(dest_group, content, controller);
> + if (rc != 0)
> + goto cleanup;
> +
> + VIR_FREE(content);
> +
> + return 0;
> +
> +cleanup:
> + /*
> + * We don't need to recover dest_cgroup because cgroup will make sure
> + * that one task only resides in one cgroup of the same controller.
> + */
> + err = virCgroupAddTaskStrController(src_group, content, controller);
> + if (err != 0)
> + VIR_ERROR(_("Cannot recover cgroup %s from %s"),
> + src_group->controllers[controller].mountPoint,
> + dest_group->controllers[controller].mountPoint);
> + VIR_FREE(content);
> +
> + return rc;
> +}
>
> /**
> * virCgroupForDriver:
> diff --git a/src/util/cgroup.h b/src/util/cgroup.h
> index 315ebd6..f14c167 100644
> --- a/src/util/cgroup.h
> +++ b/src/util/cgroup.h
> @@ -58,6 +58,14 @@ int virCgroupPathOfController(virCgroupPtr group,
>
> int virCgroupAddTask(virCgroupPtr group, pid_t pid);
>
> +int virCgroupAddTaskController(virCgroupPtr group,
> + pid_t pid,
> + int controller);
> +
> +int virCgroupMoveTask(virCgroupPtr src_group,
> + virCgroupPtr dest_group,
> + int controller);
> +
> int virCgroupSetBlkioWeight(virCgroupPtr group, unsigned int weight);
> int virCgroupGetBlkioWeight(virCgroupPtr group, unsigned int *weight);
>
> --
> 1.7.10.2
>
> --
> libvir-list mailing list
> libvir-list(a)redhat.com
> https://www.redhat.com/mailman/listinfo/libvir-list
--
Thanks,
Hu Tao