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

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&gt; Signed-off-by: Tang Chen <tangchen(a)cn.fujitsu.com&gt; Signed-off-by: Hu Tao <hutao(a)cn.fujitsu.com&gt; --- 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);

+ 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; +} +