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Groups > linux.kernel > #1478841
| From | "Fenghua Yu" <fenghua.yu@intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v2 29/33] x86/intel_rdt_rdtgroup.c: Tasks iterator and write |
| Date | 2016-09-08 09:10 +0200 |
| Message-ID | <sf1Dc-2F3-31@gated-at.bofh.it> (permalink) |
| References | <sf1tv-2mB-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Fenghua Yu <fenghua.yu@intel.com>
"tasks" file in rdtgroup contains task pids. User can move a task pid
to one directory. A task can only stay in one directory at the same
time.
Each rdtgroup contains a rg_list. When a pid is written to this
rdtgroup's tasks, the task's rg_list is added in the rdtgroup's
linked list and deleted from its previous rdtgroup's linked list.
When user reads the "tasks" file, all pids are shown in the order
from small to large.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 161 +++++++++++++++++++++++--------
1 file changed, 120 insertions(+), 41 deletions(-)
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 6c3161a..16f7195 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -63,6 +63,9 @@ static int rdtgroup_cpus_show(struct seq_file *s, void *v);
static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off);
+static int rdtgroup_tasks_show(struct seq_file *s, void *v);
+static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off);
/* rdtgroup core interface files */
static struct rftype rdtgroup_root_base_files[] = {
{
@@ -720,14 +723,41 @@ static __init void init_cache_domains(void)
void rdtgroup_exit(struct task_struct *tsk)
{
+ if (tsk->rdtgroup) {
+ atomic_dec(&tsk->rdtgroup->refcount);
+ tsk->rdtgroup = NULL;
+ }
+}
- if (!list_empty(&tsk->rg_list)) {
- struct rdtgroup *rdtgrp = tsk->rdtgroup;
+static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s)
+{
+ struct task_struct *p;
+ struct rdtgroup *this = r;
- list_del_init(&tsk->rg_list);
- tsk->rdtgroup = NULL;
- atomic_dec(&rdtgrp->refcount);
+
+ if (r == root_rdtgrp)
+ return;
+
+ rcu_read_lock();
+ for_each_process(p) {
+ if (p->rdtgroup == this)
+ seq_printf(s, "%d\n", p->pid);
}
+ rcu_read_unlock();
+}
+
+static int rdtgroup_tasks_show(struct seq_file *s, void *v)
+{
+ struct kernfs_open_file *of = s->private;
+ struct rdtgroup *rdtgrp;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (rdtgrp == NULL)
+ return -ENODEV;
+
+ show_rdt_tasks(rdtgrp, s);
+ rdtgroup_kn_unlock(of->kn);
+ return 0;
}
static void rdtgroup_destroy_locked(struct rdtgroup *rdtgrp)
@@ -781,8 +811,6 @@ static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
goto out_unlock;
}
- INIT_LIST_HEAD(&rdtgrp->pset.tasks);
-
cpumask_clear(&rdtgrp->cpu_mask);
rdtgrp->root = root;
@@ -843,7 +871,7 @@ static int rdtgroup_rmdir(struct kernfs_node *kn)
if (!rdtgrp)
return -ENODEV;
- if (!list_empty(&rdtgrp->pset.tasks)) {
+ if (atomic_read(&rdtgrp->refcount)) {
ret = -EBUSY;
goto out;
}
@@ -857,28 +885,6 @@ out:
rdtgroup_kn_unlock(kn);
return ret;
}
-static int
-rdtgroup_move_task_all(struct rdtgroup *src_rdtgrp, struct rdtgroup *dst_rdtgrp)
-{
- struct list_head *tasks;
-
- tasks = &src_rdtgrp->pset.tasks;
- while (!list_empty(tasks)) {
- struct task_struct *tsk;
- struct list_head *pos;
- pid_t pid;
- int ret;
-
- pos = tasks->next;
- tsk = list_entry(pos, struct task_struct, rg_list);
- pid = tsk->pid;
- ret = rdtgroup_move_task(pid, dst_rdtgrp, false, NULL);
- if (ret)
- return ret;
- }
-
- return 0;
-}
/*
* Forcibly remove all of subdirectories under root.
@@ -1088,22 +1094,16 @@ void rdtgroup_fork(struct task_struct *child)
{
struct rdtgroup *rdtgrp;
- INIT_LIST_HEAD(&child->rg_list);
+ child->rdtgroup = NULL;
if (!rdtgroup_mounted)
return;
- mutex_lock(&rdtgroup_mutex);
-
rdtgrp = current->rdtgroup;
if (!rdtgrp)
- goto out;
+ return;
- list_add_tail(&child->rg_list, &rdtgrp->pset.tasks);
child->rdtgroup = rdtgrp;
atomic_inc(&rdtgrp->refcount);
-
-out:
- mutex_unlock(&rdtgroup_mutex);
}
static struct dentry *rdt_mount(struct file_system_type *fs_type,
@@ -1161,8 +1161,6 @@ out_mount:
deactivate_super(pinned_sb);
}
- INIT_LIST_HEAD(&root->rdtgrp.pset.tasks);
-
cpumask_copy(&root->rdtgrp.cpu_mask, cpu_online_mask);
static_key_slow_inc(&rdt_enable_key);
rdtgroup_mounted = true;
@@ -1188,7 +1186,6 @@ static void rdt_kill_sb(struct super_block *sb)
cconfig.max_closid <<= cdp_enabled;
kernfs_kill_sb(sb);
- INIT_LIST_HEAD(&root_rdtgrp->pset.tasks);
rdtgroup_mounted = false;
mutex_unlock(&rdtgroup_mutex);
@@ -1281,3 +1278,85 @@ end:
return ret ?: nbytes;
}
+
+static int _rdtgroup_move_task(struct task_struct *tsk, struct rdtgroup *rdtgrp)
+{
+ if (tsk->rdtgroup)
+ atomic_dec(&tsk->rdtgroup->refcount);
+
+ if (rdtgrp == root_rdtgrp)
+ tsk->rdtgroup = NULL;
+ else
+ tsk->rdtgroup = rdtgrp;
+
+ atomic_inc(&rdtgrp->refcount);
+
+ return 0;
+}
+
+static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
+ bool threadgroup, struct kernfs_open_file *of)
+{
+ struct task_struct *tsk;
+ int ret;
+
+ rcu_read_lock();
+ if (pid) {
+ tsk = find_task_by_vpid(pid);
+ if (!tsk) {
+ ret = -ESRCH;
+ goto out_unlock_rcu;
+ }
+ } else {
+ tsk = current;
+ }
+
+ if (threadgroup)
+ tsk = tsk->group_leader;
+
+ get_task_struct(tsk);
+ rcu_read_unlock();
+
+ ret = rdtgroup_procs_write_permission(tsk, of);
+ if (!ret)
+ _rdtgroup_move_task(tsk, rdtgrp);
+
+ put_task_struct(tsk);
+ goto out_unlock_threadgroup;
+
+out_unlock_rcu:
+ rcu_read_unlock();
+out_unlock_threadgroup:
+ return ret;
+}
+
+ssize_t _rdtgroup_procs_write(struct rdtgroup *rdtgrp,
+ struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off, bool threadgroup)
+{
+ pid_t pid;
+ int ret;
+
+ if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
+ return -EINVAL;
+
+ ret = rdtgroup_move_task(pid, rdtgrp, threadgroup, of);
+
+ return ret ?: nbytes;
+}
+
+static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdtgroup *rdtgrp;
+ int ret;
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp)
+ return -ENODEV;
+
+ ret = _rdtgroup_procs_write(rdtgrp, of, buf, nbytes, off, false);
+
+ rdtgroup_kn_unlock(of->kn);
+ return ret;
+}
--
2.5.0
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[PATCH v2 00/33] Enable Intel Resource Allocation in Resource Director Technology "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:00 +0200
[PATCH v2 32/33] MAINTAINERS: Add maintainer for Intel RDT resource allocation "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:00 +0200
[PATCH v2 30/33] x86/intel_rdt_rdtgroup.c: Process schemata input from resctrl interface "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:00 +0200
Re: [PATCH v2 30/33] x86/intel_rdt_rdtgroup.c: Process schemata input from resctrl interface Thomas Gleixner <tglx@linutronix.de> - 2016-09-09 00:30 +0200
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Re: [PATCH v2 31/33] Documentation/kernel-parameters: Add kernel parameter "resctrl" for CAT Thomas Gleixner <tglx@linutronix.de> - 2016-09-09 00:30 +0200
[PATCH v2 28/33] x86/intel_rdt_rdtgroup.c: Read and write cpus "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 28/33] x86/intel_rdt_rdtgroup.c: Read and write cpus Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 22:30 +0200
[PATCH v2 24/33] x86/intel_rdt_rdtgroup.c: Create info directory "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 24/33] x86/intel_rdt_rdtgroup.c: Create info directory Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 18:10 +0200
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Re: [PATCH v2 11/33] x86/intel_rdt: Hot cpu support for Cache Allocation Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 12:10 +0200
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Re: [PATCH v2 13/33] Define CONFIG_INTEL_RDT Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 12:20 +0200
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Re: [PATCH v2 08/33] x86/intel_rdt: Add Class of service management Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 11:00 +0200
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[PATCH v2 20/33] x86/intel_rdt.h: Header for inter_rdt.c "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 20/33] x86/intel_rdt.h: Header for inter_rdt.c Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 14:40 +0200
[PATCH v2 10/33] x86/intel_rdt: Implement scheduling support for Intel RDT "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 10/33] x86/intel_rdt: Implement scheduling support for Intel RDT Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 12:00 +0200
[PATCH v2 16/33] x86/intel_rdt: Class of service and capacity bitmask management for CDP "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 16/33] x86/intel_rdt: Class of service and capacity bitmask management for CDP Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 12:40 +0200
[PATCH v2 04/33] drivers/base/cacheinfo.c: Export some cacheinfo functions for others to use "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 04/33] drivers/base/cacheinfo.c: Export some cacheinfo functions for others to use Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 10:30 +0200
[PATCH v2 25/33] include/linux/resctrl.h: Define fork and exit functions in a new header file "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 25/33] include/linux/resctrl.h: Define fork and exit functions in a new header file Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 18:20 +0200
[PATCH v2 27/33] x86/intel_rdt_rdtgroup.c: Implement resctrl file system commands "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 27/33] x86/intel_rdt_rdtgroup.c: Implement resctrl file system commands Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 22:20 +0200
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[PATCH v2 29/33] x86/intel_rdt_rdtgroup.c: Tasks iterator and write "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 29/33] x86/intel_rdt_rdtgroup.c: Tasks iterator and write Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 23:00 +0200
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Re: [PATCH v2 17/33] x86/intel_rdt: Hot cpu update for code data prioritization Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 12:40 +0200
[PATCH v2 06/33] Documentation, x86: Documentation for Intel resource allocation user interface "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
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Re: [PATCH v2 06/33] Documentation, x86: Documentation for Intel resource allocation user interface Fenghua Yu <fenghua.yu@intel.com> - 2016-09-09 00:20 +0200
Re: [PATCH v2 06/33] Documentation, x86: Documentation for Intel resource allocation user interface Fenghua Yu <fenghua.yu@intel.com> - 2016-09-09 06:30 +0200
[PATCH v2 03/33] x86, intel_cacheinfo: Enable cache id in x86 "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
[PATCH v2 09/33] x86/intel_rdt: Add L3 cache capacity bitmask management "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 09/33] x86/intel_rdt: Add L3 cache capacity bitmask management Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 11:50 +0200
[PATCH v2 07/33] x86/intel_rdt: Add support for Cache Allocation detection "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 07/33] x86/intel_rdt: Add support for Cache Allocation detection Borislav Petkov <bp@suse.de> - 2016-09-08 14:00 +0200
RE: [PATCH v2 07/33] x86/intel_rdt: Add support for Cache Allocation detection "Yu, Fenghua" <fenghua.yu@intel.com> - 2016-09-08 19:00 +0200
Re: [PATCH v2 07/33] x86/intel_rdt: Add support for Cache Allocation detection Borislav Petkov <bp@suse.de> - 2016-09-08 19:20 +0200
Re: [PATCH v2 07/33] x86/intel_rdt: Add support for Cache Allocation detection Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 15:20 +0200
RE: [PATCH v2 07/33] x86/intel_rdt: Add support for Cache Allocation detection "Yu, Fenghua" <fenghua.yu@intel.com> - 2016-09-08 16:00 +0200
[PATCH v2 01/33] cacheinfo: Introduce cache id "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
[PATCH v2 05/33] x86/intel_rdt: Cache Allocation documentation "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
[PATCH v2 19/33] magic number for resctrl file system "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 19/33] magic number for resctrl file system Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 12:50 +0200
Re: [PATCH v2 19/33] magic number for resctrl file system Borislav Petkov <bp@alien8.de> - 2016-09-08 12:50 +0200
[PATCH v2 21/33] x86/intel_rdt_rdtgroup.h: Header for user interface "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 21/33] x86/intel_rdt_rdtgroup.h: Header for user interface Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 14:50 +0200
[PATCH v2 26/33] Task fork and exit for rdtgroup "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 26/33] Task fork and exit for rdtgroup Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 21:50 +0200
[PATCH v2 18/33] sched.h: Add rg_list and rdtgroup in task_struct "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 18/33] sched.h: Add rg_list and rdtgroup in task_struct Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 12:40 +0200
[PATCH v2 02/33] Documentation, ABI: Add a document entry for cache id "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 02/33] Documentation, ABI: Add a document entry for cache id Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 21:40 +0200
[PATCH v2 12/33] x86/intel_rdt: Intel haswell Cache Allocation enumeration "Fenghua Yu" <fenghua.yu@intel.com> - 2016-09-08 09:10 +0200
Re: [PATCH v2 12/33] x86/intel_rdt: Intel haswell Cache Allocation enumeration Thomas Gleixner <tglx@linutronix.de> - 2016-09-08 12:20 +0200
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