Hi Babu,
On 6/1/2023 12:00 PM, 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
>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 6ad33f355861..504137a5d31f 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);
> @@ -708,16 +707,27 @@ static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
> }
> rdt_last_cmd_clear();
>
> - if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
> - rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
> - ret = -EINVAL;
> - rdt_last_cmd_puts("Pseudo-locking in progress\n");
> - goto unlock;
> - }
Please do not drop this snippet. I think there may have been misunderstanding
during previous comments - this snippet is required, it just does not need
to be run for every pid the user provides since it depends on the resource
group, not the pid.
> + while (buf && buf[0] != '\0') {
I think it may help to add a check for '\n' here also. It looks to me
that a user (shell) that provides "pid,", which is "pid,\n" would encounter
error and this may not actually be an error.
> + pid_str = strim(strsep(&buf, ","));
>
> - ret = rdtgroup_move_task(pid, rdtgrp, of);
> + if (kstrtoint(pid_str, 0, &pid)) {
> + rdt_last_cmd_puts("Task list parsing error\n");
> + ret = -EINVAL;
> + break;
> + }
>
> -unlock:
> + if (pid < 0) {
> + rdt_last_cmd_printf("Invalid pid %d value\n", pid);
> + ret = -EINVAL;
> + break;
> + }
I'm trying to image a possible error and it does not look right. For example,
the above could be "Invalid pid 123 value". How about just "Invalid pid %d".
> +
> + ret = rdtgroup_move_task(pid, rdtgrp, of);
> + if (ret) {
> + rdt_last_cmd_printf("Error while processing task %d\n", pid);
> + break;
> + }
> + }
> rdtgroup_kn_unlock(of->kn);
>
> return ret ?: nbytes;
>
>
Reinette
