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 error:
cat: /proc/1193/resctrl: No such device
Tested-by: Jinshi Chen <[email protected]>
Reviewed-by: Reinette Chatre <[email protected]>
Reviewed-by: Fenghua Yu <[email protected]>
Reviewed-by: Tony Luck <[email protected]>
Signed-off-by: Chen Yu <[email protected]>
---
arch/x86/include/asm/resctrl_sched.h | 4 +++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 46 ++++++++++++++++++++++++++
fs/proc/base.c | 9 +++++
3 files changed, 59 insertions(+)
diff --git a/arch/x86/include/asm/resctrl_sched.h b/arch/x86/include/asm/resctrl_sched.h
index f6b7fe2833cc..bba362e0e00f 100644
--- a/arch/x86/include/asm/resctrl_sched.h
+++ b/arch/x86/include/asm/resctrl_sched.h
@@ -5,6 +5,7 @@
#ifdef CONFIG_X86_CPU_RESCTRL
#include <linux/sched.h>
+#include <linux/proc_fs.h>
#include <linux/jump_label.h>
#define IA32_PQR_ASSOC 0x0c8f
@@ -84,6 +85,9 @@ static inline void resctrl_sched_in(void)
__resctrl_sched_in();
}
+int proc_resctrl_show(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *tsk);
+
#else
static inline void resctrl_sched_in(void) {}
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index a46dee8e78db..2317174174e9 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -727,6 +727,52 @@ static int rdtgroup_tasks_show(struct kernfs_open_file *of,
return ret;
}
+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);
+
+ /* Make sure resctrl has been mounted. */
+ if (!static_branch_unlikely(&rdt_enable_key)) {
+ ret = -ENODEV;
+ 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) {
+ 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;
+ }
+ }
+ ret = -ENOENT;
+unlock:
+ mutex_unlock(&rdtgroup_mutex);
+
+ return ret;
+}
+
static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
struct seq_file *seq, void *v)
{
diff --git a/fs/proc/base.c b/fs/proc/base.c
index ebea9501afb8..d8a61db78db5 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -95,6 +95,9 @@
#include <linux/sched/stat.h>
#include <linux/posix-timers.h>
#include <trace/events/oom.h>
+#ifdef CONFIG_X86_CPU_RESCTRL
+#include <asm/resctrl_sched.h>
+#endif
#include "internal.h"
#include "fd.h"
@@ -3060,6 +3063,9 @@ static const struct pid_entry tgid_base_stuff[] = {
#endif
#ifdef CONFIG_CGROUPS
ONE("cgroup", S_IRUGO, proc_cgroup_show),
+#endif
+#ifdef CONFIG_X86_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 +3466,9 @@ static const struct pid_entry tid_base_stuff[] = {
#endif
#ifdef CONFIG_CGROUPS
ONE("cgroup", S_IRUGO, proc_cgroup_show),
+#endif
+#ifdef CONFIG_X86_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),
--
2.17.1
On Thu, Nov 07, 2019 at 11:27:31AM +0800, 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
>
> If the resctrl filesystem has not been mounted,
> reading /proc/{pid}/resctrl returns an error:
> cat: /proc/1193/resctrl: No such device
>
> Tested-by: Jinshi Chen <[email protected]>
> Reviewed-by: Reinette Chatre <[email protected]>
> Reviewed-by: Fenghua Yu <[email protected]>
> Reviewed-by: Tony Luck <[email protected]>
> Signed-off-by: Chen Yu <[email protected]>
>
> ---
> arch/x86/include/asm/resctrl_sched.h | 4 +++
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 46 ++++++++++++++++++++++++++
> fs/proc/base.c | 9 +++++
^^^^^^^^^^^^^^^
So you're touching this file here and yet your Cc list doesn't have
*anyone* who might be responsible for the proc fs (yeah, you have
linux-fsdevel but I don't think that's enough). Have you heard of
scripts/get_maintainer.pl?
Use it in the future.
Cc-ing some more people for the generic /proc bits.
> 3 files changed, 59 insertions(+)
>
> diff --git a/arch/x86/include/asm/resctrl_sched.h b/arch/x86/include/asm/resctrl_sched.h
> index f6b7fe2833cc..bba362e0e00f 100644
> --- a/arch/x86/include/asm/resctrl_sched.h
> +++ b/arch/x86/include/asm/resctrl_sched.h
> @@ -5,6 +5,7 @@
> #ifdef CONFIG_X86_CPU_RESCTRL
>
> #include <linux/sched.h>
> +#include <linux/proc_fs.h>
> #include <linux/jump_label.h>
>
> #define IA32_PQR_ASSOC 0x0c8f
> @@ -84,6 +85,9 @@ static inline void resctrl_sched_in(void)
> __resctrl_sched_in();
> }
>
> +int proc_resctrl_show(struct seq_file *m, struct pid_namespace *ns,
> + struct pid *pid, struct task_struct *tsk);
> +
> #else
>
> static inline void resctrl_sched_in(void) {}
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index a46dee8e78db..2317174174e9 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -727,6 +727,52 @@ static int rdtgroup_tasks_show(struct kernfs_open_file *of,
> return ret;
> }
>
> +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);
> +
> + /* Make sure resctrl has been mounted. */
> + if (!static_branch_unlikely(&rdt_enable_key)) {
> + ret = -ENODEV;
> + 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) {
Save an indentation level:
if (rdtg->closid != tsk->closid)
continue;
seq_printf...
> + 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;
> + }
> + }
> + ret = -ENOENT;
> +unlock:
> + mutex_unlock(&rdtgroup_mutex);
> +
> + return ret;
> +}
> +
> static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
> struct seq_file *seq, void *v)
> {
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index ebea9501afb8..d8a61db78db5 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -95,6 +95,9 @@
> #include <linux/sched/stat.h>
> #include <linux/posix-timers.h>
> #include <trace/events/oom.h>
> +#ifdef CONFIG_X86_CPU_RESCTRL
> +#include <asm/resctrl_sched.h>
> +#endif
If anything, this should be abstracted nicely into an
include/linux/resctrl.h header. Other architectures would probably wanna
use it too, I hear ARM64 has something like resctrl.
> #include "internal.h"
> #include "fd.h"
>
> @@ -3060,6 +3063,9 @@ static const struct pid_entry tgid_base_stuff[] = {
> #endif
> #ifdef CONFIG_CGROUPS
> ONE("cgroup", S_IRUGO, proc_cgroup_show),
> +#endif
> +#ifdef CONFIG_X86_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 +3466,9 @@ static const struct pid_entry tid_base_stuff[] = {
> #endif
> #ifdef CONFIG_CGROUPS
> ONE("cgroup", S_IRUGO, proc_cgroup_show),
> +#endif
> +#ifdef CONFIG_X86_CPU_RESCTRL
> + ONE("resctrl", S_IRUGO, proc_resctrl_show),
> #endif
Same here. proc_resctrl_show() looks like a generic function but it
is x86-only. Need to call the x86-specific one in a real generic
proc_resctrl_show() which other arches can add their code to, too.
Not like that.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
Hi Boris,
Thanks for looking at the patch.
On Wed, Nov 13, 2019 at 07:23:07PM +0100, Borislav Petkov wrote:
> On Thu, Nov 07, 2019 at 11:27:31AM +0800, 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
> >
> > If the resctrl filesystem has not been mounted,
> > reading /proc/{pid}/resctrl returns an error:
> > cat: /proc/1193/resctrl: No such device
> >
> > Tested-by: Jinshi Chen <[email protected]>
> > Reviewed-by: Reinette Chatre <[email protected]>
> > Reviewed-by: Fenghua Yu <[email protected]>
> > Reviewed-by: Tony Luck <[email protected]>
> > Signed-off-by: Chen Yu <[email protected]>
> >
> > ---
> > arch/x86/include/asm/resctrl_sched.h | 4 +++
> > arch/x86/kernel/cpu/resctrl/rdtgroup.c | 46 ++++++++++++++++++++++++++
> > fs/proc/base.c | 9 +++++
> ^^^^^^^^^^^^^^^
>
> So you're touching this file here and yet your Cc list doesn't have
> *anyone* who might be responsible for the proc fs (yeah, you have
> linux-fsdevel but I don't think that's enough). Have you heard of
> scripts/get_maintainer.pl?
>
> Use it in the future.
>
> Cc-ing some more people for the generic /proc bits.
>
Okay, thanks.
> > 3 files changed, 59 insertions(+)
> >
> > +
> > + if (rdtg->closid == tsk->closid) {
>
> Save an indentation level:
>
> if (rdtg->closid != tsk->closid)
> continue;
>
> seq_printf...
>
Okay.
> > +#ifdef CONFIG_X86_CPU_RESCTRL
> > +#include <asm/resctrl_sched.h>
> > +#endif
>
> If anything, this should be abstracted nicely into an
> include/linux/resctrl.h header. Other architectures would probably wanna
> use it too, I hear ARM64 has something like resctrl.
>
Okay, created this header in the next version.
> > +#endif
> > +#ifdef CONFIG_X86_CPU_RESCTRL
> > + ONE("resctrl", S_IRUGO, proc_resctrl_show),
> > #endif
>
> Same here. proc_resctrl_show() looks like a generic function but it
> is x86-only. Need to call the x86-specific one in a real generic
> proc_resctrl_show() which other arches can add their code to, too.
>
> Not like that.
>
Okay, in next version proc_resctrl_show() is declared in resctrl.h.
However since there's no common c source file for resctrl currently,
different architectures might need to implement proc_resctrl_show()
accordingly - currently only x86 needs to do that.
Thanks,
Chenyu
> --
> Regards/Gruss,
> Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette
On Fri, Nov 15, 2019 at 12:24:11PM +0800, Yu Chen wrote:
> Okay, in next version proc_resctrl_show() is declared in resctrl.h.
> However since there's no common c source file for resctrl currently,
And what do we do if there's no .c file in the repo?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette