[libvirt] [PATCH RESEND RFC v4 1/6] Introduce the function virCgroupForVcpu

[Daniel Veillard]

On Thu, Jul 21, 2011 at 10:08:03AM +0800, Wen Congyang wrote:
> Introduce the function virCgroupForVcpu() to create sub directory for each vcpu.
> ---
>  src/libvirt_private.syms |    1 +
>  src/util/cgroup.c        |   72 ++++++++++++++++++++++++++++++++++++++++++---
>  src/util/cgroup.h        |    5 +++
>  3 files changed, 73 insertions(+), 5 deletions(-)
> 
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 3e3b1dd..30804eb 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -67,6 +67,7 @@ virCgroupDenyAllDevices;
>  virCgroupDenyDevicePath;
>  virCgroupForDomain;
>  virCgroupForDriver;
> +virCgroupForVcpu;
>  virCgroupFree;
>  virCgroupGetBlkioWeight;
>  virCgroupGetCpuShares;
> diff --git a/src/util/cgroup.c b/src/util/cgroup.c
> index 740cedf..8994aca 100644
> --- a/src/util/cgroup.c
> +++ b/src/util/cgroup.c
> @@ -52,6 +52,16 @@ struct virCgroup {
>      struct virCgroupController controllers[VIR_CGROUP_CONTROLLER_LAST];
>  };
>  
> +typedef enum {
> +    VIR_CGROUP_NONE = 0, /* create subdir under each cgroup if possible. */
> +    VIR_CGROUP_MEM_HIERACHY = 1 << 0, /* call virCgroupSetMemoryUseHierarchy
> +                                       * before creating subcgroups and
> +                                       * attaching tasks
> +                                       */
> +    VIR_CGROUP_VCPU = 1 << 1, /* create subdir only under the cgroup cpu,
> +                               * cpuacct and cpuset if possible. */
> +} virCgroupFlags;
> +
>  /**
>   * virCgroupFree:
>   *
> @@ -503,7 +513,7 @@ static int virCgroupSetMemoryUseHierarchy(virCgroupPtr group)
>  }
>  
>  static int virCgroupMakeGroup(virCgroupPtr parent, virCgroupPtr group,
> -                              int create, bool memory_hierarchy)
> +                              int create, unsigned int flags)
>  {
>      int i;
>      int rc = 0;
> @@ -516,6 +526,13 @@ static int virCgroupMakeGroup(virCgroupPtr parent, virCgroupPtr group,
>          if (!group->controllers[i].mountPoint)
>              continue;
>  
> +        /* We need to control cpu bandwidth for each vcpu now */
> +        if ((flags & VIR_CGROUP_VCPU) && i != VIR_CGROUP_CONTROLLER_CPU) {

  small nit, I woudl put () on both side of the &&

> +            /* treat it as unmounted and we can use virCgroupAddTask */
> +            VIR_FREE(group->controllers[i].mountPoint);
> +            continue;
> +        }
> +
>          rc = virCgroupPathOfController(group, i, "", &path);
>          if (rc < 0)
>              return rc;
> @@ -555,7 +572,7 @@ static int virCgroupMakeGroup(virCgroupPtr parent, virCgroupPtr group,
>               * Note that virCgroupSetMemoryUseHierarchy should always be
>               * called prior to creating subcgroups and attaching tasks.
>               */
> -            if (memory_hierarchy &&
> +            if ((flags & VIR_CGROUP_MEM_HIERACHY) &&
>                  group->controllers[VIR_CGROUP_CONTROLLER_MEMORY].mountPoint != NULL &&

  same here

>                  (i == VIR_CGROUP_CONTROLLER_MEMORY ||
>                   STREQ(group->controllers[i].mountPoint, group->controllers[VIR_CGROUP_CONTROLLER_MEMORY].mountPoint))) {
> @@ -641,7 +658,7 @@ static int virCgroupAppRoot(int privileged,
>      if (rc != 0)
>          goto cleanup;
>  
> -    rc = virCgroupMakeGroup(rootgrp, *group, create, false);
> +    rc = virCgroupMakeGroup(rootgrp, *group, create, VIR_CGROUP_NONE);
>  
>  cleanup:
>      virCgroupFree(&rootgrp);
> @@ -801,7 +818,7 @@ int virCgroupForDriver(const char *name,
>      VIR_FREE(path);
>  
>      if (rc == 0) {
> -        rc = virCgroupMakeGroup(rootgrp, *group, create, false);
> +        rc = virCgroupMakeGroup(rootgrp, *group, create, VIR_CGROUP_NONE);
>          if (rc != 0)
>              virCgroupFree(group);
>      }
> @@ -861,7 +878,7 @@ int virCgroupForDomain(virCgroupPtr driver,
>           * a group for driver, is to avoid overhead to track
>           * cumulative usage that we don't need.
>           */
> -        rc = virCgroupMakeGroup(driver, *group, create, true);
> +        rc = virCgroupMakeGroup(driver, *group, create, VIR_CGROUP_MEM_HIERACHY);
>          if (rc != 0)
>              virCgroupFree(group);
>      }
> @@ -879,6 +896,51 @@ int virCgroupForDomain(virCgroupPtr driver ATTRIBUTE_UNUSED,
>  #endif
>  
>  /**
> + * virCgroupForVcpu:
> + *
> + * @driver: group for the domain
> + * @vcpuid: id of the vcpu
> + * @group: Pointer to returned virCgroupPtr
> + *
> + * Returns 0 on success
> + */
> +#if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R
> +int virCgroupForVcpu(virCgroupPtr driver,
> +                     int vcpuid,
> +                     virCgroupPtr *group,
> +                     int create)
> +{
> +    int rc;
> +    char *path;
> +
> +    if (driver == NULL)
> +        return -EINVAL;
> +
> +    if (virAsprintf(&path, "%s/vcpu%d", driver->path, vcpuid) < 0)
> +        return -ENOMEM;
> +
> +    rc = virCgroupNew(path, group);
> +    VIR_FREE(path);
> +
> +    if (rc == 0) {
> +        rc = virCgroupMakeGroup(driver, *group, create, VIR_CGROUP_VCPU);
> +        if (rc != 0)
> +            virCgroupFree(group);
> +    }
> +
> +    return rc;
> +}
> +#else
> +int virCgroupForVcpu(virCgroupPtr driver ATTRIBUTE_UNUSED,
> +                     int vcpuid ATTRIBUTE_UNUSED,
> +                     virCgroupPtr *group ATTRIBUTE_UNUSED,
> +                     int create ATTRIBUTE_UNUSED)
> +{
> +    return -ENXIO;
> +}
> +#endif
> +
> +/**
>   * virCgroupSetBlkioWeight:
>   *
>   * @group: The cgroup to change io weight for
> diff --git a/src/util/cgroup.h b/src/util/cgroup.h
> index 8ae756d..1d04418 100644
> --- a/src/util/cgroup.h
> +++ b/src/util/cgroup.h
> @@ -40,6 +40,11 @@ int virCgroupForDomain(virCgroupPtr driver,
>                         virCgroupPtr *group,
>                         int create);
>  
> +int virCgroupForVcpu(virCgroupPtr driver,
> +                     int vcpuid,
> +                     virCgroupPtr *group,
> +                     int create);
> +
>  int virCgroupPathOfController(virCgroupPtr group,
>                                int controller,
>                                const char *key,
> -- 
> 1.7.1

  ACK,

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
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