From: Tejun Heo <tj@kernel.org>
To: torvalds@linux-foundation.org, mingo@redhat.com,
peterz@infradead.org, juri.lelli@redhat.com,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
bristot@redhat.com, vschneid@redhat.com, ast@kernel.org,
daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org,
joshdon@google.com, brho@google.com, pjt@google.com,
derkling@google.com, haoluo@google.com, dvernet@meta.com,
dschatzberg@meta.com, dskarlat@cs.cmu.edu, riel@surriel.com,
changwoo@igalia.com, himadrics@inria.fr, memxor@gmail.com,
andrea.righi@canonical.com, joel@joelfernandes.org
Cc: linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
kernel-team@meta.com, Tejun Heo <tj@kernel.org>
Subject: [PATCH 01/39] cgroup: Implement cgroup_show_cftypes()
Date: Wed, 1 May 2024 05:09:36 -1000 [thread overview]
Message-ID: <20240501151312.635565-2-tj@kernel.org> (raw)
In-Reply-To: <20240501151312.635565-1-tj@kernel.org>
Implement cgroup_show_cftypes() which shows and hides all cgroup files
associated with the specified set of cgroup file types. CFTYPE_HIDDEN flag
is added so that files can be created hidden from the get-go.
cgroup_show_cftypes() can be used whether the cftypes are added or not. It
also combines with cgroup_show_file() so that a given file is visible iff
both its cftype and cfile are visible.
This will be used by a new sched_class to selectively show and hide CPU
controller interface files depending on whether they're supported.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
---
include/linux/cgroup-defs.h | 8 +++
include/linux/cgroup.h | 1 +
kernel/cgroup/cgroup.c | 97 ++++++++++++++++++++++++++++++++++---
3 files changed, 99 insertions(+), 7 deletions(-)
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index ea48c861cd36..bfc027311950 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -132,12 +132,18 @@ enum {
CFTYPE_WORLD_WRITABLE = (1 << 4), /* (DON'T USE FOR NEW FILES) S_IWUGO */
CFTYPE_DEBUG = (1 << 5), /* create when cgroup_debug */
+ CFTYPE_HIDDEN = (1 << 6), /* file type hidden, see cgroup_show_cftypes() */
+
/* internal flags, do not use outside cgroup core proper */
__CFTYPE_ONLY_ON_DFL = (1 << 16), /* only on default hierarchy */
__CFTYPE_NOT_ON_DFL = (1 << 17), /* not on default hierarchy */
__CFTYPE_ADDED = (1 << 18),
};
+enum cfile_flags {
+ CFILE_HIDDEN = (1 << 0), /* file instance hidden */
+};
+
/*
* cgroup_file is the handle for a file instance created in a cgroup which
* is used, for example, to generate file changed notifications. This can
@@ -145,7 +151,9 @@ enum {
*/
struct cgroup_file {
/* do not access any fields from outside cgroup core */
+ struct cftype *cft;
struct kernfs_node *kn;
+ unsigned int flags;
unsigned long notified_at;
struct timer_list notify_timer;
};
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 34aaf0e87def..509e2e8a1d35 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -114,6 +114,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from);
int cgroup_add_dfl_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
int cgroup_add_legacy_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
int cgroup_rm_cftypes(struct cftype *cfts);
+void cgroup_show_cftype(struct cftype *cft, bool show);
void cgroup_file_notify(struct cgroup_file *cfile);
void cgroup_file_show(struct cgroup_file *cfile, bool show);
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index a66c088c851c..b316d3b7ffe7 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -4206,10 +4206,13 @@ static int cgroup_add_file(struct cgroup_subsys_state *css, struct cgroup *cgrp,
if (IS_ERR(kn))
return PTR_ERR(kn);
+ kernfs_show(kn, !(cft->flags & CFTYPE_HIDDEN));
+
if (cft->file_offset) {
struct cgroup_file *cfile = (void *)css + cft->file_offset;
timer_setup(&cfile->notify_timer, cgroup_file_notify_timer, 0);
+ cfile->cft = cft;
spin_lock_irq(&cgroup_file_kn_lock);
cfile->kn = kn;
@@ -4485,6 +4488,24 @@ void cgroup_file_notify(struct cgroup_file *cfile)
spin_unlock_irqrestore(&cgroup_file_kn_lock, flags);
}
+static struct kernfs_node *cfile_kn_get(struct cgroup_file *cfile)
+{
+ struct kernfs_node *kn;
+
+ spin_lock_irq(&cgroup_file_kn_lock);
+ kn = cfile->kn;
+ kernfs_get(kn);
+ spin_unlock_irq(&cgroup_file_kn_lock);
+
+ return kn;
+}
+
+static bool cfile_visible(struct cgroup_file *cfile)
+{
+ return !(cfile->cft->flags & CFTYPE_HIDDEN) &&
+ !(cfile->flags & CFILE_HIDDEN);
+}
+
/**
* cgroup_file_show - show or hide a hidden cgroup file
* @cfile: target cgroup_file obtained by setting cftype->file_offset
@@ -4494,15 +4515,20 @@ void cgroup_file_show(struct cgroup_file *cfile, bool show)
{
struct kernfs_node *kn;
- spin_lock_irq(&cgroup_file_kn_lock);
- kn = cfile->kn;
- kernfs_get(kn);
- spin_unlock_irq(&cgroup_file_kn_lock);
+ mutex_lock(&cgroup_mutex);
- if (kn)
- kernfs_show(kn, show);
+ if (show)
+ cfile->flags &= ~CFILE_HIDDEN;
+ else
+ cfile->flags |= CFILE_HIDDEN;
- kernfs_put(kn);
+ kn = cfile_kn_get(cfile);
+ if (kn) {
+ kernfs_show(kn, cfile_visible(cfile));
+ kernfs_put(kn);
+ }
+
+ mutex_unlock(&cgroup_mutex);
}
/**
@@ -5526,6 +5552,63 @@ static void offline_css(struct cgroup_subsys_state *css)
wake_up_all(&css->cgroup->offline_waitq);
}
+/**
+ * cgroup_show_cftype - show or hide a cgroup file type
+ * @cft: cftype to show or hide
+ * @show: whether to show or hide
+ *
+ * Sets %CFTYPE_HIDDEN and shows/hides the matching files according to @show.
+ * @cft may or may not be added at the time of this call. After hiding, it's
+ * guaranteed that there are no in-flight operations on the hidden files.
+ */
+void cgroup_show_cftype(struct cftype *cft, bool show)
+{
+ struct cgroup_subsys *ss = cft->ss;
+ struct cgroup *root = ss ? &ss->root->cgrp : &cgrp_dfl_root.cgrp;
+ struct cgroup_subsys_state *css;
+
+ mutex_lock(&cgroup_mutex);
+
+ if (show)
+ cft->flags &= ~CFTYPE_HIDDEN;
+ else
+ cft->flags |= CFTYPE_HIDDEN;
+
+ if (!(cft->flags & __CFTYPE_ADDED))
+ goto out_unlock;
+
+ css_for_each_descendant_pre(css, cgroup_css(root, ss)) {
+ struct cgroup *cgrp = css->cgroup;
+ struct kernfs_node *kn;
+
+ if (!(css->flags & CSS_VISIBLE))
+ continue;
+
+ if (cft->file_offset) {
+ struct cgroup_file *cfile =
+ (void *)css + cft->file_offset;
+
+ kn = cfile_kn_get(cfile);
+ if (kn) {
+ kernfs_show(kn, cfile_visible(cfile));
+ kernfs_put(kn);
+ }
+ } else {
+ char buf[CGROUP_FILE_NAME_MAX];
+
+ kn = kernfs_find_and_get(cgrp->kn,
+ cgroup_file_name(cgrp, cft, buf));
+ if (kn) {
+ kernfs_show(kn, show);
+ kernfs_put(kn);
+ }
+ }
+ }
+
+out_unlock:
+ mutex_unlock(&cgroup_mutex);
+}
+
/**
* css_create - create a cgroup_subsys_state
* @cgrp: the cgroup new css will be associated with
--
2.44.0
next prev parent reply other threads:[~2024-05-01 15:13 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-01 15:09 [PATCHSET v6] sched: Implement BPF extensible scheduler class Tejun Heo
2024-05-01 15:09 ` Tejun Heo [this message]
2024-05-01 15:09 ` [PATCH 02/39] sched: Restructure sched_class order sanity checks in sched_init() Tejun Heo
2024-05-01 15:09 ` [PATCH 03/39] sched: Allow sched_cgroup_fork() to fail and introduce sched_cancel_fork() Tejun Heo
2024-05-01 15:09 ` [PATCH 04/39] sched: Add sched_class->reweight_task() Tejun Heo
2024-05-01 15:09 ` [PATCH 05/39] sched: Add sched_class->switching_to() and expose check_class_changing/changed() Tejun Heo
2024-05-01 15:09 ` [PATCH 06/39] sched: Factor out cgroup weight conversion functions Tejun Heo
2024-05-01 15:09 ` [PATCH 07/39] sched: Expose css_tg() and __setscheduler_prio() Tejun Heo
2024-05-01 15:09 ` [PATCH 08/39] sched: Enumerate CPU cgroup file types Tejun Heo
2024-05-01 15:09 ` [PATCH 09/39] sched: Add @reason to sched_class->rq_{on|off}line() Tejun Heo
2024-05-01 15:09 ` [PATCH 10/39] sched: Factor out update_other_load_avgs() from __update_blocked_others() Tejun Heo
2024-05-01 15:09 ` [PATCH 11/39] cpufreq_schedutil: Refactor sugov_cpu_is_busy() Tejun Heo
2024-05-01 15:09 ` [PATCH 12/39] sched: Add normal_policy() Tejun Heo
2024-05-01 15:09 ` [PATCH 13/39] sched_ext: Add boilerplate for extensible scheduler class Tejun Heo
2024-05-01 15:09 ` [PATCH 14/39] sched_ext: Implement BPF " Tejun Heo
2024-05-01 15:09 ` [PATCH 15/39] sched_ext: Add scx_simple and scx_example_qmap example schedulers Tejun Heo
2024-05-01 15:09 ` [PATCH 16/39] sched_ext: Add sysrq-S which disables the BPF scheduler Tejun Heo
2024-05-01 15:09 ` [PATCH 17/39] sched_ext: Implement runnable task stall watchdog Tejun Heo
2024-05-01 15:09 ` [PATCH 18/39] sched_ext: Allow BPF schedulers to disallow specific tasks from joining SCHED_EXT Tejun Heo
2024-05-01 15:09 ` [PATCH 19/39] sched_ext: Print sched_ext info when dumping stack Tejun Heo
2024-05-01 15:09 ` [PATCH 20/39] sched_ext: Print debug dump after an error exit Tejun Heo
2024-05-01 15:09 ` [PATCH 21/39] tools/sched_ext: Add scx_show_state.py Tejun Heo
2024-05-01 15:09 ` [PATCH 22/39] sched_ext: Implement scx_bpf_kick_cpu() and task preemption support Tejun Heo
2024-05-01 15:09 ` [PATCH 23/39] sched_ext: Add a central scheduler which makes all scheduling decisions on one CPU Tejun Heo
2024-05-01 15:09 ` [PATCH 24/39] sched_ext: Make watchdog handle ops.dispatch() looping stall Tejun Heo
2024-05-01 15:10 ` [PATCH 25/39] sched_ext: Add task state tracking operations Tejun Heo
2024-05-01 15:10 ` [PATCH 26/39] sched_ext: Implement tickless support Tejun Heo
2024-05-01 15:10 ` [PATCH 27/39] sched_ext: Track tasks that are subjects of the in-flight SCX operation Tejun Heo
2024-05-01 15:10 ` [PATCH 28/39] sched_ext: Add cgroup support Tejun Heo
2024-05-01 15:10 ` [PATCH 29/39] sched_ext: Add a cgroup scheduler which uses flattened hierarchy Tejun Heo
2024-05-01 15:10 ` [PATCH 30/39] sched_ext: Implement SCX_KICK_WAIT Tejun Heo
2024-05-01 15:10 ` [PATCH 31/39] sched_ext: Implement sched_ext_ops.cpu_acquire/release() Tejun Heo
2024-05-01 15:10 ` [PATCH 32/39] sched_ext: Implement sched_ext_ops.cpu_online/offline() Tejun Heo
2024-05-01 15:10 ` [PATCH 33/39] sched_ext: Bypass BPF scheduler while PM events are in progress Tejun Heo
2024-05-01 15:10 ` [PATCH 34/39] sched_ext: Implement core-sched support Tejun Heo
2024-05-01 15:10 ` [PATCH 35/39] sched_ext: Add vtime-ordered priority queue to dispatch_q's Tejun Heo
2024-05-01 15:10 ` [PATCH 36/39] sched_ext: Implement DSQ iterator Tejun Heo
2024-05-01 15:10 ` [PATCH 37/39] sched_ext: Add cpuperf support Tejun Heo
2024-05-01 15:10 ` [PATCH 38/39] sched_ext: Documentation: scheduler: Document extensible scheduler class Tejun Heo
2024-05-02 2:24 ` Bagas Sanjaya
2024-05-01 15:10 ` [PATCH 39/39] sched_ext: Add selftests Tejun Heo
2024-05-02 8:48 ` [PATCHSET v6] sched: Implement BPF extensible scheduler class Peter Zijlstra
2024-05-02 19:20 ` Tejun Heo
2024-05-03 8:52 ` Peter Zijlstra
2024-05-05 23:31 ` Tejun Heo
2024-05-13 8:03 ` Peter Zijlstra
2024-05-13 18:26 ` Steven Rostedt
2024-05-14 0:07 ` Qais Yousef
2024-05-14 21:34 ` David Vernet
2024-05-17 9:58 ` Peter Zijlstra
2024-05-14 20:22 ` Chris Mason
2024-05-14 22:06 ` Josh Don
2024-05-15 20:41 ` Tejun Heo
2024-05-21 0:19 ` Tejun Heo
2024-05-06 18:47 ` Rik van Riel
2024-05-07 19:33 ` Tejun Heo
2024-05-07 19:47 ` Rik van Riel
2024-05-09 7:38 ` Changwoo Min
2024-05-10 18:24 ` Peter Jung
2024-05-13 20:36 ` Andrea Righi
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