On Fri, 15 Sep 2023, Babu Moger wrote:
> The resctrl task assignment for monitor or control group needs to be
> done one at a time. For example:
>
> $mount -t resctrl resctrl /sys/fs/resctrl/
> $mkdir /sys/fs/resctrl/ctrl_grp1
> $echo 123 > /sys/fs/resctrl/ctrl_grp1/tasks
> $echo 456 > /sys/fs/resctrl/ctrl_grp1/tasks
> $echo 789 > /sys/fs/resctrl/ctrl_grp1/tasks
>
> This is not user-friendly when dealing with hundreds of tasks.
>
> Support multiple task assignment in one command with tasks ids separated
> by commas. For example:
> $echo 123,456,789 > /sys/fs/resctrl/ctrl_grp1/tasks
>
> Reviewed-by: Tan Shaopeng <tan.shaopeng@xxxxxxxxxxxxxx>
> Tested-by: Tan Shaopeng <tan.shaopeng@xxxxxxxxxxxxxx>
> Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> Reviewed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> Documentation/arch/x86/resctrl.rst | 9 ++++++++-
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 25 ++++++++++++++++++++++---
> 2 files changed, 30 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
> index cb05d90111b4..8154e9975d1e 100644
> --- a/Documentation/arch/x86/resctrl.rst
> +++ b/Documentation/arch/x86/resctrl.rst
> @@ -299,7 +299,14 @@ All groups contain the following files:
> "tasks":
> Reading this file shows the list of all tasks that belong to
> this group. Writing a task id to the file will add a task to the
> - group. If the group is a CTRL_MON group the task is removed from
> + group. Multiple tasks can be added by separating the task ids
> + with commas. Tasks will be assigned sequentially. Multiple
> + failures are not supported. A single failure encountered while
> + attempting to assign a task will cause the operation to abort and
> + already added tasks before the failure will remain in the group.
> + Failures will be logged to /sys/fs/resctrl/info/last_cmd_status.
> +
> + If the group is a CTRL_MON group the task is removed from
> whichever previous CTRL_MON group owned the task and also from
> any MON group that owned the task. If the group is a MON group,
> then the task must already belong to the CTRL_MON parent of this
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 725344048f85..f0d163950969 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -696,11 +696,10 @@ static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
> char *buf, size_t nbytes, loff_t off)
> {
> struct rdtgroup *rdtgrp;
> + char *pid_str;
> int ret = 0;
> pid_t pid;
>
> - if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
> - return -EINVAL;
> rdtgrp = rdtgroup_kn_lock_live(of->kn);
> if (!rdtgrp) {
> rdtgroup_kn_unlock(of->kn);
> @@ -715,7 +714,27 @@ static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
> goto unlock;
> }
>
> - ret = rdtgroup_move_task(pid, rdtgrp, of);
> + while (buf && buf[0] != '\0' && buf[0] != '\n') {
> + pid_str = strim(strsep(&buf, ","));
> +
> + if (kstrtoint(pid_str, 0, &pid)) {
> + rdt_last_cmd_printf("Task list parsing error pid %s\n", pid_str);
> + ret = -EINVAL;
> + break;
> + }
> +
> + if (pid < 0) {
> + rdt_last_cmd_printf("Invalid pid %d\n", pid);
> + ret = -EINVAL;
> + break;
> + }
> +
> + ret = rdtgroup_move_task(pid, rdtgrp, of);
> + if (ret) {
> + rdt_last_cmd_printf("Error while processing task %d\n", pid);
> + break;
> + }
> + }
>
> unlock:
> rdtgroup_kn_unlock(of->kn);
>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
--
i.
