Messages in this thread | | | Date | Wed, 6 Sep 2023 09:56:55 -0500 | Subject | Re: [PATCH v8 1/8] x86/resctrl: Add multiple tasks to the resctrl group at once | From | "Moger, Babu" <> |
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Hi Fenghua,
On 9/1/2023 5:13 PM, Fenghua Yu wrote: > Hi, Babu, > > On 8/21/23 16:30, 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@jp.fujitsu.com> >> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> >> Signed-off-by: Babu Moger <babu.moger@amd.com> >> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> >> --- >> Documentation/arch/x86/resctrl.rst | 8 +++++++- >> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 25 ++++++++++++++++++++++--- >> 2 files changed, 29 insertions(+), 4 deletions(-) >> >> diff --git a/Documentation/arch/x86/resctrl.rst >> b/Documentation/arch/x86/resctrl.rst >> index cb05d90111b4..af234681756e 100644 >> --- a/Documentation/arch/x86/resctrl.rst >> +++ b/Documentation/arch/x86/resctrl.rst >> @@ -299,7 +299,13 @@ 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. > > What happens to the already moved tasks when "abort"? > > Could you please add add more details on "abort"? > > "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." Sure. > >> + 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..8c91c333f9b3 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_puts("Task list parsing error\n"); > > It would be better to show the failed pid string in the failure report: > + rdt_last_cmd_puts("Task list parsing error pid %s\n", > pid_str); > > So user will know which pid string causes the failure?
It was already discussed. Printing the characters during parsing error may not be much useful.
Thanks
Babu
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