sched/psi: Consolidate cgroup_psi()

cgroup_psi() can't return psi_group for root cgroup, so we have many
open code "psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi".

This patch move cgroup_psi() definition to <linux/psi.h>, in which
we can return psi_system for root cgroup, so can handle all cgroups.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lore.kernel.org/r/20220825164111.29534-9-zhouchengming@bytedance.com

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index b0914aa..80cb970 100644 (file)
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -673,11 +673,6 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
        pr_cont_kernfs_path(cgrp->kn);
 }
 
-static inline struct psi_group *cgroup_psi(struct cgroup *cgrp)
-{
-       return cgrp->psi;
-}
-
 bool cgroup_psi_enabled(void);
 
 static inline void cgroup_init_kthreadd(void)

diff --git a/include/linux/psi.h b/include/linux/psi.h
index fffd229..362a74c 100644 (file)
--- a/include/linux/psi.h
+++ b/include/linux/psi.h
@@ -7,6 +7,7 @@
 #include <linux/sched.h>
 #include <linux/poll.h>
 #include <linux/cgroup-defs.h>
+#include <linux/cgroup.h>
 
 struct seq_file;
 struct css_set;
@@ -30,6 +31,11 @@ __poll_t psi_trigger_poll(void **trigger_ptr, struct file *file,
                        poll_table *wait);
 
 #ifdef CONFIG_CGROUPS
+static inline struct psi_group *cgroup_psi(struct cgroup *cgrp)
+{
+       return cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;
+}
+
 int psi_cgroup_alloc(struct cgroup *cgrp);
 void psi_cgroup_free(struct cgroup *cgrp);
 void cgroup_move_task(struct task_struct *p, struct css_set *to);

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index b46d39b..772b35d 100644 (file)
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3689,21 +3689,21 @@ static int cpu_stat_show(struct seq_file *seq, void *v)
 static int cgroup_io_pressure_show(struct seq_file *seq, void *v)
 {
        struct cgroup *cgrp = seq_css(seq)->cgroup;
-       struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;
+       struct psi_group *psi = cgroup_psi(cgrp);
 
        return psi_show(seq, psi, PSI_IO);
 }
 static int cgroup_memory_pressure_show(struct seq_file *seq, void *v)
 {
        struct cgroup *cgrp = seq_css(seq)->cgroup;
-       struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;
+       struct psi_group *psi = cgroup_psi(cgrp);
 
        return psi_show(seq, psi, PSI_MEM);
 }
 static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v)
 {
        struct cgroup *cgrp = seq_css(seq)->cgroup;
-       struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;
+       struct psi_group *psi = cgroup_psi(cgrp);
 
        return psi_show(seq, psi, PSI_CPU);
 }
@@ -3729,7 +3729,7 @@ static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
                return -EBUSY;
        }
 
-       psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;
+       psi = cgroup_psi(cgrp);
        new = psi_trigger_create(psi, buf, res);
        if (IS_ERR(new)) {
                cgroup_put(cgrp);
@@ -3767,7 +3767,7 @@ static ssize_t cgroup_cpu_pressure_write(struct kernfs_open_file *of,
 static int cgroup_irq_pressure_show(struct seq_file *seq, void *v)
 {
        struct cgroup *cgrp = seq_css(seq)->cgroup;
-       struct psi_group *psi = cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;
+       struct psi_group *psi = cgroup_psi(cgrp);
 
        return psi_show(seq, psi, PSI_IRQ);
 }