From: Babu Moger babu.moger@amd.com
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@amd.com Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Reviewed-by: Peter Newman peternewman@google.com Reviewed-by: Tan Shaopeng tan.shaopeng@jp.fujitsu.com Reviewed-by: Fenghua Yu fenghua.yu@intel.com Reviewed-by: Reinette Chatre reinette.chatre@intel.com Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Tested-by: Peter Newman peternewman@google.com Tested-by: Tan Shaopeng tan.shaopeng@jp.fujitsu.com Link: https://lore.kernel.org/r/20231017002308.134480-2-babu.moger@amd.com --- 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 09848ff11f7b..fe239691628a 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);