| Message ID | 20191120081628.26701-1-yu.c.chen@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] x86/resctrl: Add task resctrl information display | expand |
On Wed, 20 Nov 2019, Chen Yu wrote: > Monitoring tools that want to find out which resctrl CTRL > and MONITOR groups a task belongs to must currently read > the "tasks" file in every group until they locate the process > ID. > > Add an additional file /proc/{pid}/resctrl to provide this > information. > > For example: > cat /proc/1193/resctrl > CTRL_MON:/ctrl_grp0 > MON:/ctrl_grp0/mon_groups/mon_grp0 The formatting is quite ugly and I don't see why this needs to be multiple lines and have these uppercase prefixes. A task can only be part of one control group and of one monitoring group which is associated to the control group. So just providing: 1) "" 2) "/" 3) "/mon_groups/mon0" 4) "/group0" 5) "/group0/mon_groups/mon1" is simple and clear enough, i.e.: #1: Resctrl is not available #2: Task is part of the root group, task not associated to any monitoring group #3: Task is part of the root group and monitoring group mon0 #4: Task is part of control group group0, task not associated to any monitoring group #5: Task is part of control group group0 and monitoring group mon1 Hmm? Thanks, tglx
Hi Thomas, On Wed, Nov 20, 2019 at 7:23 PM Thomas Gleixner <tglx@linutronix.de> wrote: > > On Wed, 20 Nov 2019, Chen Yu wrote: > > Monitoring tools that want to find out which resctrl CTRL > > and MONITOR groups a task belongs to must currently read > > the "tasks" file in every group until they locate the process > > ID. > > > > Add an additional file /proc/{pid}/resctrl to provide this > > information. > > > > For example: > > cat /proc/1193/resctrl > > CTRL_MON:/ctrl_grp0 > > MON:/ctrl_grp0/mon_groups/mon_grp0 > > The formatting is quite ugly and I don't see why this needs to be multiple > lines and have these uppercase prefixes. > > A task can only be part of one control group and of one monitoring group > which is associated to the control group. So just providing: > > 1) "" > 2) "/" > 3) "/mon_groups/mon0" > 4) "/group0" > 5) "/group0/mon_groups/mon1" > > is simple and clear enough, i.e.: > > #1: Resctrl is not available > > #2: Task is part of the root group, task not associated to any monitoring > group > > #3: Task is part of the root group and monitoring group mon0 > > #4: Task is part of control group group0, task not associated to any > monitoring group > > #5: Task is part of control group group0 and monitoring group mon1 > > Hmm? > Yes, good idea, this is much more simpler. I'll send the new version out based on this. Thanks, Chenyu
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8ef85139553f..252364d18887 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -455,6 +455,7 @@ config X86_CPU_RESCTRL bool "x86 CPU resource control support" depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) select KERNFS + select PROC_CPU_RESCTRL if PROC_FS help Enable x86 CPU resource control support. diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 2e3b06d6bbc6..657c21ffbdfa 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -725,6 +725,58 @@ static int rdtgroup_tasks_show(struct kernfs_open_file *of, return ret; } +#ifdef CONFIG_PROC_CPU_RESCTRL + +int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns, + struct pid *pid, struct task_struct *tsk) +{ + struct rdtgroup *rdtg; + int ret = 0; + + mutex_lock(&rdtgroup_mutex); + + /* Return empty if resctrl has not been mounted. */ + if (!static_branch_unlikely(&rdt_enable_key)) + goto unlock; + + list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) { + struct rdtgroup *crg; + + /* + * Task information is only relevant for shareable + * and exclusive groups. + */ + if (rdtg->mode != RDT_MODE_SHAREABLE && + rdtg->mode != RDT_MODE_EXCLUSIVE) + continue; + + if (rdtg->closid != tsk->closid) + continue; + + seq_printf(s, "CTRL_MON:/%s\n", rdtg->kn->name); + list_for_each_entry(crg, &rdtg->mon.crdtgrp_list, + mon.crdtgrp_list) { + if (tsk->rmid != crg->mon.rmid) + continue; + seq_printf(s, "MON:%s%s/mon_groups/%s\n", + rdtg == &rdtgroup_default ? "" : "/", + rdtg->kn->name, crg->kn->name); + goto unlock; + } + goto unlock; + } + /* + * The above search should succeed. Otherwise return + * with an error. + */ + ret = -ENOENT; +unlock: + mutex_unlock(&rdtgroup_mutex); + + return ret; +} +#endif + static int rdt_last_cmd_status_show(struct kernfs_open_file *of, struct seq_file *seq, void *v) { diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig index cb5629bd5fff..ae96a339d24d 100644 --- a/fs/proc/Kconfig +++ b/fs/proc/Kconfig @@ -103,3 +103,7 @@ config PROC_CHILDREN config PROC_PID_ARCH_STATUS def_bool n depends on PROC_FS + +config PROC_CPU_RESCTRL + def_bool n + depends on PROC_FS diff --git a/fs/proc/base.c b/fs/proc/base.c index ebea9501afb8..0e4b8bf2b986 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -94,6 +94,7 @@ #include <linux/sched/debug.h> #include <linux/sched/stat.h> #include <linux/posix-timers.h> +#include <linux/resctrl.h> #include <trace/events/oom.h> #include "internal.h" #include "fd.h" @@ -3060,6 +3061,9 @@ static const struct pid_entry tgid_base_stuff[] = { #endif #ifdef CONFIG_CGROUPS ONE("cgroup", S_IRUGO, proc_cgroup_show), +#endif +#ifdef CONFIG_PROC_CPU_RESCTRL + ONE("resctrl", S_IRUGO, proc_resctrl_show), #endif ONE("oom_score", S_IRUGO, proc_oom_score), REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), @@ -3460,6 +3464,9 @@ static const struct pid_entry tid_base_stuff[] = { #endif #ifdef CONFIG_CGROUPS ONE("cgroup", S_IRUGO, proc_cgroup_show), +#endif +#ifdef CONFIG_PROC_CPU_RESCTRL + ONE("resctrl", S_IRUGO, proc_resctrl_show), #endif ONE("oom_score", S_IRUGO, proc_oom_score), REG("oom_adj", S_IRUGO|S_IWUSR, proc_oom_adj_operations), diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h new file mode 100644 index 000000000000..50b147784d55 --- /dev/null +++ b/include/linux/resctrl.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _RESCTRL_H +#define _RESCTRL_H + +#ifdef CONFIG_PROC_CPU_RESCTRL + +#include <linux/proc_fs.h> + +int proc_resctrl_show(struct seq_file *m, + struct pid_namespace *ns, + struct pid *pid, + struct task_struct *tsk); + +#endif + +#endif /* _RESCTRL_H */
Monitoring tools that want to find out which resctrl CTRL and MONITOR groups a task belongs to must currently read the "tasks" file in every group until they locate the process ID. Add an additional file /proc/{pid}/resctrl to provide this information. For example: cat /proc/1193/resctrl CTRL_MON:/ctrl_grp0 MON:/ctrl_grp0/mon_groups/mon_grp0 If the resctrl filesystem has not been mounted, reading /proc/{pid}/resctrl returns an empty string. Signed-off-by: Chen Yu <yu.c.chen@intel.com> --- v2: Reduce indentation level in proc_resctrl_show() according to Boris's suggestion. Create the include/linux/resctrl.h header and declare proc_resctrl_show() in this file, so that other architectures would probably use it in the future. Different architectures should implement architectural specific proc_resctrl_show() accordingly. v3: Return empty string if the resctrl filesystem has not been mounted per Boris's suggestion. Rename the config from CPU_RESCTRL to PROC_CPU_RESCTRL to better represent its usage. Move PROC_CPU_RESCTRL from arch/Kconfig to fs/proc/Kconfig. And let PROC_CPU_RESCTRL to be depended on PROC_FS. --- arch/x86/Kconfig | 1 + arch/x86/kernel/cpu/resctrl/rdtgroup.c | 52 ++++++++++++++++++++++++++ fs/proc/Kconfig | 4 ++ fs/proc/base.c | 7 ++++ include/linux/resctrl.h | 16 ++++++++ 5 files changed, 80 insertions(+) create mode 100644 include/linux/resctrl.h