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Commit 9f77da9f authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Ingo Molnar
Browse files

rcu: Move private definitions from include/linux/rcutree.h to kernel/rcutree.h 



Some information hiding that makes it easier to merge
preemptability into rcutree without descending into #include
hell.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josht@linux.vnet.ibm.com
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
LKML-Reference: <1250974613373-git-send-email->
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent b560d8ad

include/linux/rcutree.h

+0 −211
Original line number Diff line number Diff line
@@ -30,217 +30,6 @@ 
#ifndef __LINUX_RCUTREE_H

#define __LINUX_RCUTREE_H



#include <linux/cache.h>

#include <linux/spinlock.h>

#include <linux/threads.h>

#include <linux/cpumask.h>

#include <linux/seqlock.h>



/*

 * Define shape of hierarchy based on NR_CPUS and CONFIG_RCU_FANOUT.

 * In theory, it should be possible to add more levels straightforwardly.

 * In practice, this has not been tested, so there is probably some

 * bug somewhere.

 */

#define MAX_RCU_LVLS 3

#define RCU_FANOUT	      (CONFIG_RCU_FANOUT)

#define RCU_FANOUT_SQ	      (RCU_FANOUT * RCU_FANOUT)

#define RCU_FANOUT_CUBE	      (RCU_FANOUT_SQ * RCU_FANOUT)



#if NR_CPUS <= RCU_FANOUT

#  define NUM_RCU_LVLS	      1

#  define NUM_RCU_LVL_0	      1

#  define NUM_RCU_LVL_1	      (NR_CPUS)

#  define NUM_RCU_LVL_2	      0

#  define NUM_RCU_LVL_3	      0

#elif NR_CPUS <= RCU_FANOUT_SQ

#  define NUM_RCU_LVLS	      2

#  define NUM_RCU_LVL_0	      1

#  define NUM_RCU_LVL_1	      (((NR_CPUS) + RCU_FANOUT - 1) / RCU_FANOUT)

#  define NUM_RCU_LVL_2	      (NR_CPUS)

#  define NUM_RCU_LVL_3	      0

#elif NR_CPUS <= RCU_FANOUT_CUBE

#  define NUM_RCU_LVLS	      3

#  define NUM_RCU_LVL_0	      1

#  define NUM_RCU_LVL_1	      (((NR_CPUS) + RCU_FANOUT_SQ - 1) / RCU_FANOUT_SQ)

#  define NUM_RCU_LVL_2	      (((NR_CPUS) + (RCU_FANOUT) - 1) / (RCU_FANOUT))

#  define NUM_RCU_LVL_3	      NR_CPUS

#else

# error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"

#endif /* #if (NR_CPUS) <= RCU_FANOUT */



#define RCU_SUM (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3)

#define NUM_RCU_NODES (RCU_SUM - NR_CPUS)



/*

 * Dynticks per-CPU state.

 */

struct rcu_dynticks {

	int dynticks_nesting;	/* Track nesting level, sort of. */

	int dynticks;		/* Even value for dynticks-idle, else odd. */

	int dynticks_nmi;	/* Even value for either dynticks-idle or */

				/*  not in nmi handler, else odd.  So this */

				/*  remains even for nmi from irq handler. */

};



/*

 * Definition for node within the RCU grace-period-detection hierarchy.

 */

struct rcu_node {

	spinlock_t lock;

	unsigned long qsmask;	/* CPUs or groups that need to switch in */

				/*  order for current grace period to proceed.*/

	unsigned long qsmaskinit;

				/* Per-GP initialization for qsmask. */

	unsigned long grpmask;	/* Mask to apply to parent qsmask. */

	int	grplo;		/* lowest-numbered CPU or group here. */

	int	grphi;		/* highest-numbered CPU or group here. */

	u8	grpnum;		/* CPU/group number for next level up. */

	u8	level;		/* root is at level 0. */

	struct rcu_node *parent;

} ____cacheline_internodealigned_in_smp;



/* Index values for nxttail array in struct rcu_data. */

#define RCU_DONE_TAIL		0	/* Also RCU_WAIT head. */

#define RCU_WAIT_TAIL		1	/* Also RCU_NEXT_READY head. */

#define RCU_NEXT_READY_TAIL	2	/* Also RCU_NEXT head. */

#define RCU_NEXT_TAIL		3

#define RCU_NEXT_SIZE		4



/* Per-CPU data for read-copy update. */

struct rcu_data {

	/* 1) quiescent-state and grace-period handling : */

	long		completed;	/* Track rsp->completed gp number */

					/*  in order to detect GP end. */

	long		gpnum;		/* Highest gp number that this CPU */

					/*  is aware of having started. */

	long		passed_quiesc_completed;

					/* Value of completed at time of qs. */

	bool		passed_quiesc;	/* User-mode/idle loop etc. */

	bool		qs_pending;	/* Core waits for quiesc state. */

	bool		beenonline;	/* CPU online at least once. */

	struct rcu_node *mynode;	/* This CPU's leaf of hierarchy */

	unsigned long grpmask;		/* Mask to apply to leaf qsmask. */



	/* 2) batch handling */

	/*

	 * If nxtlist is not NULL, it is partitioned as follows.

	 * Any of the partitions might be empty, in which case the

	 * pointer to that partition will be equal to the pointer for

	 * the following partition.  When the list is empty, all of

	 * the nxttail elements point to nxtlist, which is NULL.

	 *

	 * [*nxttail[RCU_NEXT_READY_TAIL], NULL = *nxttail[RCU_NEXT_TAIL]):

	 *	Entries that might have arrived after current GP ended

	 * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):

	 *	Entries known to have arrived before current GP ended

	 * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):

	 *	Entries that batch # <= ->completed - 1: waiting for current GP

	 * [nxtlist, *nxttail[RCU_DONE_TAIL]):

	 *	Entries that batch # <= ->completed

	 *	The grace period for these entries has completed, and

	 *	the other grace-period-completed entries may be moved

	 *	here temporarily in rcu_process_callbacks().

	 */

	struct rcu_head *nxtlist;

	struct rcu_head **nxttail[RCU_NEXT_SIZE];

	long		qlen; 	 	/* # of queued callbacks */

	long		blimit;		/* Upper limit on a processed batch */



#ifdef CONFIG_NO_HZ

	/* 3) dynticks interface. */

	struct rcu_dynticks *dynticks;	/* Shared per-CPU dynticks state. */

	int dynticks_snap;		/* Per-GP tracking for dynticks. */

	int dynticks_nmi_snap;		/* Per-GP tracking for dynticks_nmi. */

#endif /* #ifdef CONFIG_NO_HZ */



	/* 4) reasons this CPU needed to be kicked by force_quiescent_state */

#ifdef CONFIG_NO_HZ

	unsigned long dynticks_fqs;	/* Kicked due to dynticks idle. */

#endif /* #ifdef CONFIG_NO_HZ */

	unsigned long offline_fqs;	/* Kicked due to being offline. */

	unsigned long resched_ipi;	/* Sent a resched IPI. */



	/* 5) __rcu_pending() statistics. */

	long n_rcu_pending;		/* rcu_pending() calls since boot. */

	long n_rp_qs_pending;

	long n_rp_cb_ready;

	long n_rp_cpu_needs_gp;

	long n_rp_gp_completed;

	long n_rp_gp_started;

	long n_rp_need_fqs;

	long n_rp_need_nothing;



	int cpu;

};



/* Values for signaled field in struct rcu_state. */

#define RCU_GP_INIT		0	/* Grace period being initialized. */

#define RCU_SAVE_DYNTICK	1	/* Need to scan dyntick state. */

#define RCU_FORCE_QS		2	/* Need to force quiescent state. */

#ifdef CONFIG_NO_HZ

#define RCU_SIGNAL_INIT		RCU_SAVE_DYNTICK

#else /* #ifdef CONFIG_NO_HZ */

#define RCU_SIGNAL_INIT		RCU_FORCE_QS

#endif /* #else #ifdef CONFIG_NO_HZ */



#define RCU_JIFFIES_TILL_FORCE_QS	 3	/* for rsp->jiffies_force_qs */

#ifdef CONFIG_RCU_CPU_STALL_DETECTOR

#define RCU_SECONDS_TILL_STALL_CHECK   (10 * HZ)  /* for rsp->jiffies_stall */

#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ)  /* for rsp->jiffies_stall */

#define RCU_STALL_RAT_DELAY		2	  /* Allow other CPUs time */

						  /*  to take at least one */

						  /*  scheduling clock irq */

						  /*  before ratting on them. */



#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */



/*

 * RCU global state, including node hierarchy.  This hierarchy is

 * represented in "heap" form in a dense array.  The root (first level)

 * of the hierarchy is in ->node[0] (referenced by ->level[0]), the second

 * level in ->node[1] through ->node[m] (->node[1] referenced by ->level[1]),

 * and the third level in ->node[m+1] and following (->node[m+1] referenced

 * by ->level[2]).  The number of levels is determined by the number of

 * CPUs and by CONFIG_RCU_FANOUT.  Small systems will have a "hierarchy"

 * consisting of a single rcu_node.

 */

struct rcu_state {

	struct rcu_node node[NUM_RCU_NODES];	/* Hierarchy. */

	struct rcu_node *level[NUM_RCU_LVLS];	/* Hierarchy levels. */

	u32 levelcnt[MAX_RCU_LVLS + 1];		/* # nodes in each level. */

	u8 levelspread[NUM_RCU_LVLS];		/* kids/node in each level. */

	struct rcu_data *rda[NR_CPUS];		/* array of rdp pointers. */



	/* The following fields are guarded by the root rcu_node's lock. */



	u8	signaled ____cacheline_internodealigned_in_smp;

						/* Force QS state. */

	long	gpnum;				/* Current gp number. */

	long	completed;			/* # of last completed gp. */

	spinlock_t onofflock;			/* exclude on/offline and */

						/*  starting new GP. */

	spinlock_t fqslock;			/* Only one task forcing */

						/*  quiescent states. */

	unsigned long jiffies_force_qs;		/* Time at which to invoke */

						/*  force_quiescent_state(). */

	unsigned long n_force_qs;		/* Number of calls to */

						/*  force_quiescent_state(). */

	unsigned long n_force_qs_lh;		/* ~Number of calls leaving */

						/*  due to lock unavailable. */

	unsigned long n_force_qs_ngp;		/* Number of calls leaving */

						/*  due to no GP active. */

#ifdef CONFIG_RCU_CPU_STALL_DETECTOR

	unsigned long gp_start;			/* Time at which GP started, */

						/*  but in jiffies. */

	unsigned long jiffies_stall;		/* Time at which to check */

						/*  for CPU stalls. */

#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */

#ifdef CONFIG_NO_HZ

	long dynticks_completed;		/* Value of completed @ snap. */

#endif /* #ifdef CONFIG_NO_HZ */

};



extern void rcu_qsctr_inc(int cpu);

extern void rcu_bh_qsctr_inc(int cpu);

kernel/rcutree.c

+2 −0
Original line number Diff line number Diff line
@@ -46,6 +46,8 @@ 
#include <linux/mutex.h>

#include <linux/time.h>



#include "rcutree.h"



#ifdef CONFIG_DEBUG_LOCK_ALLOC

static struct lock_class_key rcu_lock_key;

struct lockdep_map rcu_lock_map =

kernel/rcutree.h

+238 −0
Original line number Diff line number Diff line 
/*

 * Read-Copy Update mechanism for mutual exclusion (tree-based version)

 * Internal non-public definitions.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 *

 * Copyright IBM Corporation, 2008

 *

 * Author: Ingo Molnar <mingo@elte.hu>

 *	   Paul E. McKenney <paulmck@linux.vnet.ibm.com>

 */



#include <linux/cache.h>

#include <linux/spinlock.h>

#include <linux/threads.h>

#include <linux/cpumask.h>

#include <linux/seqlock.h>



/*

 * Define shape of hierarchy based on NR_CPUS and CONFIG_RCU_FANOUT.

 * In theory, it should be possible to add more levels straightforwardly.

 * In practice, this has not been tested, so there is probably some

 * bug somewhere.

 */

#define MAX_RCU_LVLS 3

#define RCU_FANOUT	      (CONFIG_RCU_FANOUT)

#define RCU_FANOUT_SQ	      (RCU_FANOUT * RCU_FANOUT)

#define RCU_FANOUT_CUBE	      (RCU_FANOUT_SQ * RCU_FANOUT)



#if NR_CPUS <= RCU_FANOUT

#  define NUM_RCU_LVLS	      1

#  define NUM_RCU_LVL_0	      1

#  define NUM_RCU_LVL_1	      (NR_CPUS)

#  define NUM_RCU_LVL_2	      0

#  define NUM_RCU_LVL_3	      0

#elif NR_CPUS <= RCU_FANOUT_SQ

#  define NUM_RCU_LVLS	      2

#  define NUM_RCU_LVL_0	      1

#  define NUM_RCU_LVL_1	      (((NR_CPUS) + RCU_FANOUT - 1) / RCU_FANOUT)

#  define NUM_RCU_LVL_2	      (NR_CPUS)

#  define NUM_RCU_LVL_3	      0

#elif NR_CPUS <= RCU_FANOUT_CUBE

#  define NUM_RCU_LVLS	      3

#  define NUM_RCU_LVL_0	      1

#  define NUM_RCU_LVL_1	      (((NR_CPUS) + RCU_FANOUT_SQ - 1) / RCU_FANOUT_SQ)

#  define NUM_RCU_LVL_2	      (((NR_CPUS) + (RCU_FANOUT) - 1) / (RCU_FANOUT))

#  define NUM_RCU_LVL_3	      NR_CPUS

#else

# error "CONFIG_RCU_FANOUT insufficient for NR_CPUS"

#endif /* #if (NR_CPUS) <= RCU_FANOUT */



#define RCU_SUM (NUM_RCU_LVL_0 + NUM_RCU_LVL_1 + NUM_RCU_LVL_2 + NUM_RCU_LVL_3)

#define NUM_RCU_NODES (RCU_SUM - NR_CPUS)



/*

 * Dynticks per-CPU state.

 */

struct rcu_dynticks {

	int dynticks_nesting;	/* Track nesting level, sort of. */

	int dynticks;		/* Even value for dynticks-idle, else odd. */

	int dynticks_nmi;	/* Even value for either dynticks-idle or */

				/*  not in nmi handler, else odd.  So this */

				/*  remains even for nmi from irq handler. */

};



/*

 * Definition for node within the RCU grace-period-detection hierarchy.

 */

struct rcu_node {

	spinlock_t lock;

	unsigned long qsmask;	/* CPUs or groups that need to switch in */

				/*  order for current grace period to proceed.*/

	unsigned long qsmaskinit;

				/* Per-GP initialization for qsmask. */

	unsigned long grpmask;	/* Mask to apply to parent qsmask. */

	int	grplo;		/* lowest-numbered CPU or group here. */

	int	grphi;		/* highest-numbered CPU or group here. */

	u8	grpnum;		/* CPU/group number for next level up. */

	u8	level;		/* root is at level 0. */

	struct rcu_node *parent;

} ____cacheline_internodealigned_in_smp;



/* Index values for nxttail array in struct rcu_data. */

#define RCU_DONE_TAIL		0	/* Also RCU_WAIT head. */

#define RCU_WAIT_TAIL		1	/* Also RCU_NEXT_READY head. */

#define RCU_NEXT_READY_TAIL	2	/* Also RCU_NEXT head. */

#define RCU_NEXT_TAIL		3

#define RCU_NEXT_SIZE		4



/* Per-CPU data for read-copy update. */

struct rcu_data {

	/* 1) quiescent-state and grace-period handling : */

	long		completed;	/* Track rsp->completed gp number */

					/*  in order to detect GP end. */

	long		gpnum;		/* Highest gp number that this CPU */

					/*  is aware of having started. */

	long		passed_quiesc_completed;

					/* Value of completed at time of qs. */

	bool		passed_quiesc;	/* User-mode/idle loop etc. */

	bool		qs_pending;	/* Core waits for quiesc state. */

	bool		beenonline;	/* CPU online at least once. */

	struct rcu_node *mynode;	/* This CPU's leaf of hierarchy */

	unsigned long grpmask;		/* Mask to apply to leaf qsmask. */



	/* 2) batch handling */

	/*

	 * If nxtlist is not NULL, it is partitioned as follows.

	 * Any of the partitions might be empty, in which case the

	 * pointer to that partition will be equal to the pointer for

	 * the following partition.  When the list is empty, all of

	 * the nxttail elements point to nxtlist, which is NULL.

	 *

	 * [*nxttail[RCU_NEXT_READY_TAIL], NULL = *nxttail[RCU_NEXT_TAIL]):

	 *	Entries that might have arrived after current GP ended

	 * [*nxttail[RCU_WAIT_TAIL], *nxttail[RCU_NEXT_READY_TAIL]):

	 *	Entries known to have arrived before current GP ended

	 * [*nxttail[RCU_DONE_TAIL], *nxttail[RCU_WAIT_TAIL]):

	 *	Entries that batch # <= ->completed - 1: waiting for current GP

	 * [nxtlist, *nxttail[RCU_DONE_TAIL]):

	 *	Entries that batch # <= ->completed

	 *	The grace period for these entries has completed, and

	 *	the other grace-period-completed entries may be moved

	 *	here temporarily in rcu_process_callbacks().

	 */

	struct rcu_head *nxtlist;

	struct rcu_head **nxttail[RCU_NEXT_SIZE];

	long		qlen; 	 	/* # of queued callbacks */

	long		blimit;		/* Upper limit on a processed batch */



#ifdef CONFIG_NO_HZ

	/* 3) dynticks interface. */

	struct rcu_dynticks *dynticks;	/* Shared per-CPU dynticks state. */

	int dynticks_snap;		/* Per-GP tracking for dynticks. */

	int dynticks_nmi_snap;		/* Per-GP tracking for dynticks_nmi. */

#endif /* #ifdef CONFIG_NO_HZ */



	/* 4) reasons this CPU needed to be kicked by force_quiescent_state */

#ifdef CONFIG_NO_HZ

	unsigned long dynticks_fqs;	/* Kicked due to dynticks idle. */

#endif /* #ifdef CONFIG_NO_HZ */

	unsigned long offline_fqs;	/* Kicked due to being offline. */

	unsigned long resched_ipi;	/* Sent a resched IPI. */



	/* 5) __rcu_pending() statistics. */

	long n_rcu_pending;		/* rcu_pending() calls since boot. */

	long n_rp_qs_pending;

	long n_rp_cb_ready;

	long n_rp_cpu_needs_gp;

	long n_rp_gp_completed;

	long n_rp_gp_started;

	long n_rp_need_fqs;

	long n_rp_need_nothing;



	int cpu;

};



/* Values for signaled field in struct rcu_state. */

#define RCU_GP_INIT		0	/* Grace period being initialized. */

#define RCU_SAVE_DYNTICK	1	/* Need to scan dyntick state. */

#define RCU_FORCE_QS		2	/* Need to force quiescent state. */

#ifdef CONFIG_NO_HZ

#define RCU_SIGNAL_INIT		RCU_SAVE_DYNTICK

#else /* #ifdef CONFIG_NO_HZ */

#define RCU_SIGNAL_INIT		RCU_FORCE_QS

#endif /* #else #ifdef CONFIG_NO_HZ */



#define RCU_JIFFIES_TILL_FORCE_QS	 3	/* for rsp->jiffies_force_qs */

#ifdef CONFIG_RCU_CPU_STALL_DETECTOR

#define RCU_SECONDS_TILL_STALL_CHECK   (10 * HZ)  /* for rsp->jiffies_stall */

#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ)  /* for rsp->jiffies_stall */

#define RCU_STALL_RAT_DELAY		2	  /* Allow other CPUs time */

						  /*  to take at least one */

						  /*  scheduling clock irq */

						  /*  before ratting on them. */



#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */



/*

 * RCU global state, including node hierarchy.  This hierarchy is

 * represented in "heap" form in a dense array.  The root (first level)

 * of the hierarchy is in ->node[0] (referenced by ->level[0]), the second

 * level in ->node[1] through ->node[m] (->node[1] referenced by ->level[1]),

 * and the third level in ->node[m+1] and following (->node[m+1] referenced

 * by ->level[2]).  The number of levels is determined by the number of

 * CPUs and by CONFIG_RCU_FANOUT.  Small systems will have a "hierarchy"

 * consisting of a single rcu_node.

 */

struct rcu_state {

	struct rcu_node node[NUM_RCU_NODES];	/* Hierarchy. */

	struct rcu_node *level[NUM_RCU_LVLS];	/* Hierarchy levels. */

	u32 levelcnt[MAX_RCU_LVLS + 1];		/* # nodes in each level. */

	u8 levelspread[NUM_RCU_LVLS];		/* kids/node in each level. */

	struct rcu_data *rda[NR_CPUS];		/* array of rdp pointers. */



	/* The following fields are guarded by the root rcu_node's lock. */



	u8	signaled ____cacheline_internodealigned_in_smp;

						/* Force QS state. */

	long	gpnum;				/* Current gp number. */

	long	completed;			/* # of last completed gp. */

	spinlock_t onofflock;			/* exclude on/offline and */

						/*  starting new GP. */

	spinlock_t fqslock;			/* Only one task forcing */

						/*  quiescent states. */

	unsigned long jiffies_force_qs;		/* Time at which to invoke */

						/*  force_quiescent_state(). */

	unsigned long n_force_qs;		/* Number of calls to */

						/*  force_quiescent_state(). */

	unsigned long n_force_qs_lh;		/* ~Number of calls leaving */

						/*  due to lock unavailable. */

	unsigned long n_force_qs_ngp;		/* Number of calls leaving */

						/*  due to no GP active. */

#ifdef CONFIG_RCU_CPU_STALL_DETECTOR

	unsigned long gp_start;			/* Time at which GP started, */

						/*  but in jiffies. */

	unsigned long jiffies_stall;		/* Time at which to check */

						/*  for CPU stalls. */

#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */

#ifdef CONFIG_NO_HZ

	long dynticks_completed;		/* Value of completed @ snap. */

#endif /* #ifdef CONFIG_NO_HZ */

};



#ifdef RCU_TREE_NONCORE



/*

 * RCU implementation internal declarations:
@@ -8,3 +244,5 @@ DECLARE_PER_CPU(struct rcu_data, rcu_data); 
extern struct rcu_state rcu_bh_state;

DECLARE_PER_CPU(struct rcu_data, rcu_bh_data);



#endif /* #ifdef RCU_TREE_NONCORE */

kernel/rcutree_trace.c

+1 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include <linux/debugfs.h>

#include <linux/seq_file.h>



#define RCU_TREE_NONCORE

#include "rcutree.h"



static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)