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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2009-06-23 20:12:47 -0400
committerIngo Molnar <mingo@elte.hu>2009-06-24 09:05:13 -0400
commitc17ef45342cc033fdf7bdd5b28615e0090f8d2e7 (patch)
tree6bb4b1d09f0801d5e3ad5a727e14035090b25931 /include/linux/rcuclassic.h
parentf6faac71d502be1c29c81b2f45657662c3b84470 (diff)
rcu: Remove Classic RCU
Remove Classic RCU, given that the combination of Tree RCU and the proposed Bloatwatch RCU do everything that Classic RCU can with fewer bugs. Tree RCU has been default in x86 builds for almost six months, and seems to be quite reliable, so there does not seem to be much justification for keeping the Classic RCU code and config complexity around anymore. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: akpm@linux-foundation.org Cc: niv@us.ibm.com Cc: dvhltc@us.ibm.com Cc: dipankar@in.ibm.com Cc: dhowells@redhat.com Cc: lethal@linux-sh.org Cc: kernel@wantstofly.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/rcuclassic.h')
-rw-r--r--include/linux/rcuclassic.h178
1 files changed, 0 insertions, 178 deletions
diff --git a/include/linux/rcuclassic.h b/include/linux/rcuclassic.h
deleted file mode 100644
index bfd92e1e5d2c..000000000000
--- a/include/linux/rcuclassic.h
+++ /dev/null
@@ -1,178 +0,0 @@
1/*
2 * Read-Copy Update mechanism for mutual exclusion (classic version)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Copyright IBM Corporation, 2001
19 *
20 * Author: Dipankar Sarma <dipankar@in.ibm.com>
21 *
22 * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
23 * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
24 * Papers:
25 * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf
26 * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
27 *
28 * For detailed explanation of Read-Copy Update mechanism see -
29 * Documentation/RCU
30 *
31 */
32
33#ifndef __LINUX_RCUCLASSIC_H
34#define __LINUX_RCUCLASSIC_H
35
36#include <linux/cache.h>
37#include <linux/spinlock.h>
38#include <linux/threads.h>
39#include <linux/cpumask.h>
40#include <linux/seqlock.h>
41
42#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
43#define RCU_SECONDS_TILL_STALL_CHECK (10 * HZ) /* for rcp->jiffies_stall */
44#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ) /* for rcp->jiffies_stall */
45#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
46
47/* Global control variables for rcupdate callback mechanism. */
48struct rcu_ctrlblk {
49 long cur; /* Current batch number. */
50 long completed; /* Number of the last completed batch */
51 long pending; /* Number of the last pending batch */
52#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
53 unsigned long gp_start; /* Time at which GP started in jiffies. */
54 unsigned long jiffies_stall;
55 /* Time at which to check for CPU stalls. */
56#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
57
58 int signaled;
59
60 spinlock_t lock ____cacheline_internodealigned_in_smp;
61 DECLARE_BITMAP(cpumask, NR_CPUS); /* CPUs that need to switch for */
62 /* current batch to proceed. */
63} ____cacheline_internodealigned_in_smp;
64
65/* Is batch a before batch b ? */
66static inline int rcu_batch_before(long a, long b)
67{
68 return (a - b) < 0;
69}
70
71/* Is batch a after batch b ? */
72static inline int rcu_batch_after(long a, long b)
73{
74 return (a - b) > 0;
75}
76
77/* Per-CPU data for Read-Copy UPdate. */
78struct rcu_data {
79 /* 1) quiescent state handling : */
80 long quiescbatch; /* Batch # for grace period */
81 int passed_quiesc; /* User-mode/idle loop etc. */
82 int qs_pending; /* core waits for quiesc state */
83
84 /* 2) batch handling */
85 /*
86 * if nxtlist is not NULL, then:
87 * batch:
88 * The batch # for the last entry of nxtlist
89 * [*nxttail[1], NULL = *nxttail[2]):
90 * Entries that batch # <= batch
91 * [*nxttail[0], *nxttail[1]):
92 * Entries that batch # <= batch - 1
93 * [nxtlist, *nxttail[0]):
94 * Entries that batch # <= batch - 2
95 * The grace period for these entries has completed, and
96 * the other grace-period-completed entries may be moved
97 * here temporarily in rcu_process_callbacks().
98 */
99 long batch;
100 struct rcu_head *nxtlist;
101 struct rcu_head **nxttail[3];
102 long qlen; /* # of queued callbacks */
103 struct rcu_head *donelist;
104 struct rcu_head **donetail;
105 long blimit; /* Upper limit on a processed batch */
106 int cpu;
107 struct rcu_head barrier;
108};
109
110/*
111 * Increment the quiescent state counter.
112 * The counter is a bit degenerated: We do not need to know
113 * how many quiescent states passed, just if there was at least
114 * one since the start of the grace period. Thus just a flag.
115 */
116extern void rcu_qsctr_inc(int cpu);
117extern void rcu_bh_qsctr_inc(int cpu);
118
119extern int rcu_pending(int cpu);
120extern int rcu_needs_cpu(int cpu);
121
122#ifdef CONFIG_DEBUG_LOCK_ALLOC
123extern struct lockdep_map rcu_lock_map;
124# define rcu_read_acquire() \
125 lock_acquire(&rcu_lock_map, 0, 0, 2, 1, NULL, _THIS_IP_)
126# define rcu_read_release() lock_release(&rcu_lock_map, 1, _THIS_IP_)
127#else
128# define rcu_read_acquire() do { } while (0)
129# define rcu_read_release() do { } while (0)
130#endif
131
132#define __rcu_read_lock() \
133 do { \
134 preempt_disable(); \
135 __acquire(RCU); \
136 rcu_read_acquire(); \
137 } while (0)
138#define __rcu_read_unlock() \
139 do { \
140 rcu_read_release(); \
141 __release(RCU); \
142 preempt_enable(); \
143 } while (0)
144#define __rcu_read_lock_bh() \
145 do { \
146 local_bh_disable(); \
147 __acquire(RCU_BH); \
148 rcu_read_acquire(); \
149 } while (0)
150#define __rcu_read_unlock_bh() \
151 do { \
152 rcu_read_release(); \
153 __release(RCU_BH); \
154 local_bh_enable(); \
155 } while (0)
156
157#define __synchronize_sched() synchronize_rcu()
158
159#define call_rcu_sched(head, func) call_rcu(head, func)
160
161extern void __rcu_init(void);
162#define rcu_init_sched() do { } while (0)
163extern void rcu_check_callbacks(int cpu, int user);
164extern void rcu_restart_cpu(int cpu);
165
166extern long rcu_batches_completed(void);
167extern long rcu_batches_completed_bh(void);
168
169#define rcu_enter_nohz() do { } while (0)
170#define rcu_exit_nohz() do { } while (0)
171
172/* A context switch is a grace period for rcuclassic. */
173static inline int rcu_blocking_is_gp(void)
174{
175 return num_online_cpus() == 1;
176}
177
178#endif /* __LINUX_RCUCLASSIC_H */
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