[libvirt] [PATCH v2 02/17] Introduce the function virCgroupMoveTask

[Hu Tao]

On Tue, Aug 21, 2012 at 02:43:52PM +0800, Hu Tao wrote:
> Introduce a new API to move tasks of one controller from a cgroup to another cgroup
> 
> Signed-off-by: Wen Congyang <wency at cn.fujitsu.com>
> Signed-off-by: Tang Chen <tangchen at cn.fujitsu.com>
> Signed-off-by: Hu Tao <hutao at cn.fujitsu.com>
> ---
>  src/libvirt_private.syms |    2 +
>  src/util/cgroup.c        |  109 ++++++++++++++++++++++++++++++++++++++++++++++
>  src/util/cgroup.h        |    8 ++++
>  3 files changed, 119 insertions(+)
> 
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 681f526..0934dba 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -60,6 +60,7 @@ virCapabilitiesSetMacPrefix;
>  
>  # cgroup.h
>  virCgroupAddTask;
> +virCgroupAddTaskController;
>  virCgroupAllowDevice;
>  virCgroupAllowDeviceMajor;
>  virCgroupAllowDevicePath;
> @@ -91,6 +92,7 @@ virCgroupKill;
>  virCgroupKillPainfully;
>  virCgroupKillRecursive;
>  virCgroupMounted;
> +virCgroupMoveTask;
>  virCgroupPathOfController;
>  virCgroupRemove;
>  virCgroupSetBlkioDeviceWeight;
> diff --git a/src/util/cgroup.c b/src/util/cgroup.c
> index 169b56a..374516a 100644
> --- a/src/util/cgroup.c
> +++ b/src/util/cgroup.c
> @@ -802,6 +802,115 @@ 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)
> +{
> +    if (controller < VIR_CGROUP_CONTROLLER_CPU ||
> +        controller > VIR_CGROUP_CONTROLLER_BLKIO)
> +        return -EINVAL;
> +
> +    if (!group->controllers[controller].mountPoint)
> +        return -EINVAL;
> +
> +    return virCgroupSetValueU64(group, controller, "tasks",
> +                                (unsigned long long)pid);
> +}
> +
> +
> +static int virCgroupAddTaskStrController(virCgroupPtr group,
> +                                        const char *pidstr,
> +                                        int controller)
> +{
> +    char *str = NULL, *cur = NULL, *next = NULL;
> +    unsigned long long p = 0;
> +    int rc = 0;
> +
> +    if (virAsprintf(&str, "%s", pidstr) < 0)
> +        return -1;
> +
> +    cur = str;
> +    while (*cur != '\0') {
> +        rc = virStrToLong_ull(cur, NULL, 10, &p);

The terminating '\n' in str will cause a failure here.
It can be fixed by(can you squash this in?):

diff --git a/src/util/cgroup.c b/src/util/cgroup.c
index 840a952..1808911 100644
--- a/src/util/cgroup.c
+++ b/src/util/cgroup.c
@@ -833,13 +833,14 @@ static int virCgroupAddTaskStrController(virCgroupPtr group,
     char *str = NULL, *cur = NULL, *next = NULL;
     unsigned long long p = 0;
     int rc = 0;
+    char *endp;
 
     if (virAsprintf(&str, "%s", pidstr) < 0)
         return -1;
 
     cur = str;
     while (*cur != '\0') {
-        rc = virStrToLong_ull(cur, NULL, 10, &p);
+        rc = virStrToLong_ull(cur, &endp, 10, &p);
         if (rc != 0)
             goto cleanup;
 

> +        if (rc != 0)
> +            goto cleanup;
> +
> +        rc = virCgroupAddTaskController(group, p, controller);
> +        if (rc != 0)
> +            goto cleanup;
> +
> +        next = strchr(cur, '\n');
> +        if (next) {
> +            cur = next + 1;
> +            *next = '\0';
> +        } else {
> +            break;
> +        }
> +    }
> +
> +cleanup:
> +    VIR_FREE(str);
> +    return rc;
> +}
> +

-- 
Thanks,
Hu Tao