From: Waiman Long <longman@redhat.com>
To: Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>
Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com,
luto@amacapital.net, Mike Galbraith <efault@gmx.de>,
torvalds@linux-foundation.org, Roman Gushchin <guro@fb.com>,
Juri Lelli <juri.lelli@redhat.com>,
Patrick Bellasi <patrick.bellasi@arm.com>,
Tom Hromatka <tom.hromatka@oracle.com>,
Waiman Long <longman@redhat.com>
Subject: [PATCH v15 10/12] cpuset: Use descriptive text when reading/writing cpuset.sched.partition
Date: Thu, 8 Nov 2018 10:08:44 -0500 [thread overview]
Message-ID: <1541689726-20088-11-git-send-email-longman@redhat.com> (raw)
In-Reply-To: <1541689726-20088-1-git-send-email-longman@redhat.com>
Currently, cpuset.sched.partition returns the values, 0, 1 or -1 on
read. A person who is not familiar with the partition code may not
understand what they mean.
In order to make cpuset.sched.partition more user-friendly, it will
now display the following descriptive text on read:
"root" - A partition root (top cpuset of a partition)
"member" - A non-root member of a partition
"root invalid" - An invalid partition root
Note that there is at least one partition in the whole cgroup hierarchy.
The top cpuset is the root of that partition. The rests are either a
root if it starts a new partition or a member of a partition.
The cpuset.sched.partition file will now also accept "root" and
"member" besides 1 and 0 as valid input values. The "root invalid"
value is internal only and cannot be written to the file.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/cgroup/cpuset.c | 58 ++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 51 insertions(+), 7 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index fc1a809..c739fda 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -2278,9 +2278,6 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
case FILE_SCHED_RELAX_DOMAIN_LEVEL:
retval = update_relax_domain_level(cs, val);
break;
- case FILE_PARTITION_ROOT:
- retval = update_prstate(cs, val);
- break;
default:
retval = -EINVAL;
break;
@@ -2431,8 +2428,6 @@ static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft)
switch (type) {
case FILE_SCHED_RELAX_DOMAIN_LEVEL:
return cs->relax_domain_level;
- case FILE_PARTITION_ROOT:
- return cs->partition_root_state;
default:
BUG();
}
@@ -2441,6 +2436,55 @@ static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft)
return 0;
}
+static int sched_partition_show(struct seq_file *seq, void *v)
+{
+ struct cpuset *cs = css_cs(seq_css(seq));
+
+ switch (cs->partition_root_state) {
+ case PRS_ENABLED:
+ seq_puts(seq, "root\n");
+ break;
+ case PRS_DISABLED:
+ seq_puts(seq, "member\n");
+ break;
+ case PRS_ERROR:
+ seq_puts(seq, "root invalid\n");
+ break;
+ }
+ return 0;
+}
+
+static ssize_t sched_partition_write(struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off)
+{
+ struct cpuset *cs = css_cs(of_css(of));
+ int val;
+ int retval = -ENODEV;
+
+ buf = strstrip(buf);
+
+ /*
+ * Convert "root"/"1" to 1, and convert "member"/"0" to 0.
+ */
+ if (!strcmp(buf, "root") || !strcmp(buf, "1"))
+ val = PRS_ENABLED;
+ else if (!strcmp(buf, "member") || !strcmp(buf, "0"))
+ val = PRS_DISABLED;
+ else
+ return -EINVAL;
+
+ css_get(&cs->css);
+ mutex_lock(&cpuset_mutex);
+ if (!is_cpuset_online(cs))
+ goto out_unlock;
+
+ retval = update_prstate(cs, val);
+out_unlock:
+ mutex_unlock(&cpuset_mutex);
+ css_put(&cs->css);
+ return retval ?: nbytes;
+}
+
/*
* for the common functions, 'private' gives the type of file
*/
@@ -2584,8 +2628,8 @@ static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft)
{
.name = "sched.partition",
- .read_s64 = cpuset_read_s64,
- .write_s64 = cpuset_write_s64,
+ .seq_show = sched_partition_show,
+ .write = sched_partition_write,
.private = FILE_PARTITION_ROOT,
.flags = CFTYPE_NOT_ON_ROOT,
},
--
1.8.3.1
next prev parent reply other threads:[~2018-11-08 15:09 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-08 15:08 [PATCH v15 00/12] Enable cpuset controller in default hierarchy Waiman Long
2018-11-08 15:08 ` [PATCH v15 01/12] cpuset: " Waiman Long
2018-11-08 15:08 ` [PATCH v15 02/12] cpuset: Define data structures to support scheduling partition Waiman Long
2018-11-08 15:08 ` [PATCH v15 03/12] cpuset: Simply allocation and freeing of cpumasks Waiman Long
2018-11-08 15:08 ` [PATCH v15 04/12] cpuset: Add new v2 cpuset.sched.partition flag Waiman Long
2018-11-08 15:08 ` [PATCH v15 05/12] cpuset: Add an error state to cpuset.sched.partition Waiman Long
2018-11-08 15:08 ` [PATCH v15 06/12] cpuset: Track cpusets that use parent's effective_cpus Waiman Long
2018-11-08 15:08 ` [PATCH v15 07/12] cpuset: Make CPU hotplug work with partition Waiman Long
2018-11-08 15:08 ` [PATCH v15 08/12] cpuset: Make generate_sched_domains() " Waiman Long
2018-11-08 15:08 ` [PATCH v15 09/12] cpuset: Expose cpus.effective and mems.effective on cgroup v2 root Waiman Long
2018-11-08 15:08 ` Waiman Long [this message]
2018-11-08 15:08 ` [PATCH v15 11/12] cpuset: Add documentation about the new "cpuset.sched.partition" flag Waiman Long
2018-11-08 15:08 ` [PATCH v15 12/12] cpuset: Expose cpuset.cpus.subpartitions with cgroup_debug Waiman Long
2018-11-08 15:46 ` Peter Zijlstra
2018-11-08 18:59 ` Waiman Long
2018-11-08 15:46 ` [PATCH v15 00/12] Enable cpuset controller in default hierarchy Peter Zijlstra
2018-11-08 20:28 ` Tejun Heo
2018-11-08 20:31 ` Waiman Long
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