psi: cgroup support (2ce7135a) · Commits · 戴 / test

Documentation/accounting/psi.txt

+9 −0

Original line number	Original line	Diff line number	Diff line
	@@ -62,3 +62,12 @@ well as medium and long term trends. The total absolute stall time is
	tracked and exported as well, to allow detection of latency spikes		tracked and exported as well, to allow detection of latency spikes
	which wouldn't necessarily make a dent in the time averages, or to		which wouldn't necessarily make a dent in the time averages, or to
	average trends over custom time frames.		average trends over custom time frames.

			Cgroup2 interface
			=================

			In a system with a CONFIG_CGROUP=y kernel and the cgroup2 filesystem
			mounted, pressure stall information is also tracked for tasks grouped
			into cgroups. Each subdirectory in the cgroupfs mountpoint contains
			cpu.pressure, memory.pressure, and io.pressure files; the format is
			the same as the /proc/pressure/ files.

Documentation/admin-guide/cgroup-v2.rst

+18 −0

Original line number	Original line	Diff line number	Diff line
	@@ -966,6 +966,12 @@ All time durations are in microseconds.
	$PERIOD duration. "max" for $MAX indicates no limit. If only		$PERIOD duration. "max" for $MAX indicates no limit. If only
	one number is written, $MAX is updated.		one number is written, $MAX is updated.

			cpu.pressure
			A read-only nested-key file which exists on non-root cgroups.

			Shows pressure stall information for CPU. See
			Documentation/accounting/psi.txt for details.


	Memory		Memory
	------		------
	@@ -1271,6 +1277,12 @@ PAGE_SIZE multiple when read back.
	higher than the limit for an extended period of time. This		higher than the limit for an extended period of time. This
	reduces the impact on the workload and memory management.		reduces the impact on the workload and memory management.

			memory.pressure
			A read-only nested-key file which exists on non-root cgroups.

			Shows pressure stall information for memory. See
			Documentation/accounting/psi.txt for details.


	Usage Guidelines		Usage Guidelines
	~~~~~~~~~~~~~~~~		~~~~~~~~~~~~~~~~
	@@ -1408,6 +1420,12 @@ IO Interface Files

	8:16 rbps=2097152 wbps=max riops=max wiops=max		8:16 rbps=2097152 wbps=max riops=max wiops=max

			io.pressure
			A read-only nested-key file which exists on non-root cgroups.

			Shows pressure stall information for IO. See
			Documentation/accounting/psi.txt for details.


	Writeback		Writeback
	~~~~~~~~~		~~~~~~~~~

include/linux/cgroup-defs.h

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -20,6 +20,7 @@
	#include <linux/u64_stats_sync.h>		#include <linux/u64_stats_sync.h>
	#include <linux/workqueue.h>		#include <linux/workqueue.h>
	#include <linux/bpf-cgroup.h>		#include <linux/bpf-cgroup.h>
			#include <linux/psi_types.h>

	#ifdef CONFIG_CGROUPS		#ifdef CONFIG_CGROUPS

	@@ -436,6 +437,9 @@ struct cgroup {
	/* used to schedule release agent */		/* used to schedule release agent */
	struct work_struct release_agent_work;		struct work_struct release_agent_work;

			/* used to track pressure stalls */
			struct psi_group psi;

	/* used to store eBPF programs */		/* used to store eBPF programs */
	struct cgroup_bpf bpf;		struct cgroup_bpf bpf;

include/linux/cgroup.h

+15 −0

Original line number	Original line	Diff line number	Diff line
	@@ -650,6 +650,11 @@ static inline void pr_cont_cgroup_path(struct cgroup *cgrp)
	pr_cont_kernfs_path(cgrp->kn);		pr_cont_kernfs_path(cgrp->kn);
	}		}

			static inline struct psi_group cgroup_psi(struct cgroup cgrp)
			{
			return &cgrp->psi;
			}

	static inline void cgroup_init_kthreadd(void)		static inline void cgroup_init_kthreadd(void)
	{		{
	/*		/*
	@@ -703,6 +708,16 @@ static inline union kernfs_node_id cgroup_get_kernfs_id(struct cgroup cgrp)
	return NULL;		return NULL;
	}		}

			static inline struct cgroup cgroup_parent(struct cgroup cgrp)
			{
			return NULL;
			}

			static inline struct psi_group cgroup_psi(struct cgroup cgrp)
			{
			return NULL;
			}

	static inline bool task_under_cgroup_hierarchy(struct task_struct *task,		static inline bool task_under_cgroup_hierarchy(struct task_struct *task,
	struct cgroup *ancestor)		struct cgroup *ancestor)
	{		{

include/linux/psi.h

+25 −0

Original line number	Original line	Diff line number	Diff line
	@@ -4,6 +4,9 @@
	#include <linux/psi_types.h>		#include <linux/psi_types.h>
	#include <linux/sched.h>		#include <linux/sched.h>

			struct seq_file;
			struct css_set;

	#ifdef CONFIG_PSI		#ifdef CONFIG_PSI

	extern bool psi_disabled;		extern bool psi_disabled;
	@@ -16,6 +19,14 @@ void psi_memstall_tick(struct task_struct *task, int cpu);
	void psi_memstall_enter(unsigned long *flags);		void psi_memstall_enter(unsigned long *flags);
	void psi_memstall_leave(unsigned long *flags);		void psi_memstall_leave(unsigned long *flags);

			int psi_show(struct seq_file s, struct psi_group group, enum psi_res res);

			#ifdef CONFIG_CGROUPS
			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);
			#endif

	#else /* CONFIG_PSI */		#else /* CONFIG_PSI */

	static inline void psi_init(void) {}		static inline void psi_init(void) {}
	@@ -23,6 +34,20 @@ static inline void psi_init(void) {}
	static inline void psi_memstall_enter(unsigned long *flags) {}		static inline void psi_memstall_enter(unsigned long *flags) {}
	static inline void psi_memstall_leave(unsigned long *flags) {}		static inline void psi_memstall_leave(unsigned long *flags) {}

			#ifdef CONFIG_CGROUPS
			static inline int psi_cgroup_alloc(struct cgroup *cgrp)
			{
			return 0;
			}
			static inline void psi_cgroup_free(struct cgroup *cgrp)
			{
			}
			static inline void cgroup_move_task(struct task_struct p, struct css_set to)
			{
			rcu_assign_pointer(p->cgroups, to);
			}
			#endif

	#endif /* CONFIG_PSI */		#endif /* CONFIG_PSI */

	#endif /* _LINUX_PSI_H */		#endif /* _LINUX_PSI_H */

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