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    Subject[patch 2/3] RCU move trace defines to rcupdate_types.h
    Given tracepoint.h need to include the minimal set of headers, split some
    RCU defines from the global rcupdate.h header.

    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
    CC: Jeremy Fitzhardinge <jeremy@goop.org>
    CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
    CC: Steven Rostedt <rostedt@goodmis.org>
    CC: Ingo Molnar <mingo@elte.hu>
    CC: Andrew Morton <akpm@linux-foundation.org>
    CC: Christoph Hellwig <hch@lst.de>
    ---
    include/linux/rcupdate.h | 128 --------------------------------
    include/linux/rcupdate_types.h | 163 +++++++++++++++++++++++++++++++++++++++++
    2 files changed, 165 insertions(+), 126 deletions(-)

    Index: linux.trees.git/include/linux/rcupdate.h
    ===================================================================
    --- linux.trees.git.orig/include/linux/rcupdate.h 2009-04-16 20:34:19.000000000 -0400
    +++ linux.trees.git/include/linux/rcupdate.h 2009-04-16 20:35:23.000000000 -0400
    @@ -40,6 +40,7 @@
    #include <linux/seqlock.h>
    #include <linux/lockdep.h>
    #include <linux/completion.h>
    +#include <linux/rcupdate_types.h>

    /**
    * struct rcu_head - callback structure for use with RCU
    @@ -70,132 +71,7 @@ extern int rcu_scheduler_active;
    (ptr)->next = NULL; (ptr)->func = NULL; \
    } while (0)

    -/**
    - * rcu_read_lock - mark the beginning of an RCU read-side critical section.
    - *
    - * When synchronize_rcu() is invoked on one CPU while other CPUs
    - * are within RCU read-side critical sections, then the
    - * synchronize_rcu() is guaranteed to block until after all the other
    - * CPUs exit their critical sections. Similarly, if call_rcu() is invoked
    - * on one CPU while other CPUs are within RCU read-side critical
    - * sections, invocation of the corresponding RCU callback is deferred
    - * until after the all the other CPUs exit their critical sections.
    - *
    - * Note, however, that RCU callbacks are permitted to run concurrently
    - * with RCU read-side critical sections. One way that this can happen
    - * is via the following sequence of events: (1) CPU 0 enters an RCU
    - * read-side critical section, (2) CPU 1 invokes call_rcu() to register
    - * an RCU callback, (3) CPU 0 exits the RCU read-side critical section,
    - * (4) CPU 2 enters a RCU read-side critical section, (5) the RCU
    - * callback is invoked. This is legal, because the RCU read-side critical
    - * section that was running concurrently with the call_rcu() (and which
    - * therefore might be referencing something that the corresponding RCU
    - * callback would free up) has completed before the corresponding
    - * RCU callback is invoked.
    - *
    - * RCU read-side critical sections may be nested. Any deferred actions
    - * will be deferred until the outermost RCU read-side critical section
    - * completes.
    - *
    - * It is illegal to block while in an RCU read-side critical section.
    - */
    -#define rcu_read_lock() __rcu_read_lock()
    -
    -/**
    - * rcu_read_unlock - marks the end of an RCU read-side critical section.
    - *
    - * See rcu_read_lock() for more information.
    - */
    -
    -/*
    - * So where is rcu_write_lock()? It does not exist, as there is no
    - * way for writers to lock out RCU readers. This is a feature, not
    - * a bug -- this property is what provides RCU's performance benefits.
    - * Of course, writers must coordinate with each other. The normal
    - * spinlock primitives work well for this, but any other technique may be
    - * used as well. RCU does not care how the writers keep out of each
    - * others' way, as long as they do so.
    - */
    -#define rcu_read_unlock() __rcu_read_unlock()
    -
    -/**
    - * rcu_read_lock_bh - mark the beginning of a softirq-only RCU critical section
    - *
    - * This is equivalent of rcu_read_lock(), but to be used when updates
    - * are being done using call_rcu_bh(). Since call_rcu_bh() callbacks
    - * consider completion of a softirq handler to be a quiescent state,
    - * a process in RCU read-side critical section must be protected by
    - * disabling softirqs. Read-side critical sections in interrupt context
    - * can use just rcu_read_lock().
    - *
    - */
    -#define rcu_read_lock_bh() __rcu_read_lock_bh()
    -
    -/*
    - * rcu_read_unlock_bh - marks the end of a softirq-only RCU critical section
    - *
    - * See rcu_read_lock_bh() for more information.
    - */
    -#define rcu_read_unlock_bh() __rcu_read_unlock_bh()
    -
    -/**
    - * rcu_read_lock_sched - mark the beginning of a RCU-classic critical section
    - *
    - * Should be used with either
    - * - synchronize_sched()
    - * or
    - * - call_rcu_sched() and rcu_barrier_sched()
    - * on the write-side to insure proper synchronization.
    - */
    -#define rcu_read_lock_sched() preempt_disable()
    -#define rcu_read_lock_sched_notrace() preempt_disable_notrace()
    -
    -/*
    - * rcu_read_unlock_sched - marks the end of a RCU-classic critical section
    - *
    - * See rcu_read_lock_sched for more information.
    - */
    -#define rcu_read_unlock_sched() preempt_enable()
    -#define rcu_read_unlock_sched_notrace() preempt_enable_notrace()
    -
    -
    -
    -/**
    - * rcu_dereference - fetch an RCU-protected pointer in an
    - * RCU read-side critical section. This pointer may later
    - * be safely dereferenced.
    - *
    - * Inserts memory barriers on architectures that require them
    - * (currently only the Alpha), and, more importantly, documents
    - * exactly which pointers are protected by RCU.
    - */
    -
    -#define rcu_dereference(p) ({ \
    - typeof(p) _________p1 = ACCESS_ONCE(p); \
    - smp_read_barrier_depends(); \
    - (_________p1); \
    - })
    -
    -/**
    - * rcu_assign_pointer - assign (publicize) a pointer to a newly
    - * initialized structure that will be dereferenced by RCU read-side
    - * critical sections. Returns the value assigned.
    - *
    - * Inserts memory barriers on architectures that require them
    - * (pretty much all of them other than x86), and also prevents
    - * the compiler from reordering the code that initializes the
    - * structure after the pointer assignment. More importantly, this
    - * call documents which pointers will be dereferenced by RCU read-side
    - * code.
    - */
    -
    -#define rcu_assign_pointer(p, v) \
    - ({ \
    - if (!__builtin_constant_p(v) || \
    - ((v) != NULL)) \
    - smp_wmb(); \
    - (p) = (v); \
    - })
    +/* See linux/rcupdate_types.h for read-side locking primitives */

    /* Infrastructure to implement the synchronize_() primitives. */

    Index: linux.trees.git/include/linux/rcupdate_types.h
    ===================================================================
    --- /dev/null 1970-01-01 00:00:00.000000000 +0000
    +++ linux.trees.git/include/linux/rcupdate_types.h 2009-04-16 20:35:09.000000000 -0400
    @@ -0,0 +1,163 @@
    +/*
    + * Read-Copy Update mechanism for mutual exclusion - read-side 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, 2001
    + *
    + * Author: Dipankar Sarma <dipankar@in.ibm.com>
    + *
    + * Based on the original work by Paul McKenney <paulmck@us.ibm.com>
    + * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
    + * Papers:
    + * http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf
    + * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
    + *
    + * For detailed explanation of Read-Copy Update mechanism see -
    + * http://lse.sourceforge.net/locking/rcupdate.html
    + *
    + */
    +
    +#ifndef __LINUX_RCUPDATE_TYPES_H
    +#define __LINUX_RCUPDATE_TYPES_H
    +
    +/**
    + * rcu_read_lock - mark the beginning of an RCU read-side critical section.
    + *
    + * When synchronize_rcu() is invoked on one CPU while other CPUs
    + * are within RCU read-side critical sections, then the
    + * synchronize_rcu() is guaranteed to block until after all the other
    + * CPUs exit their critical sections. Similarly, if call_rcu() is invoked
    + * on one CPU while other CPUs are within RCU read-side critical
    + * sections, invocation of the corresponding RCU callback is deferred
    + * until after the all the other CPUs exit their critical sections.
    + *
    + * Note, however, that RCU callbacks are permitted to run concurrently
    + * with RCU read-side critical sections. One way that this can happen
    + * is via the following sequence of events: (1) CPU 0 enters an RCU
    + * read-side critical section, (2) CPU 1 invokes call_rcu() to register
    + * an RCU callback, (3) CPU 0 exits the RCU read-side critical section,
    + * (4) CPU 2 enters a RCU read-side critical section, (5) the RCU
    + * callback is invoked. This is legal, because the RCU read-side critical
    + * section that was running concurrently with the call_rcu() (and which
    + * therefore might be referencing something that the corresponding RCU
    + * callback would free up) has completed before the corresponding
    + * RCU callback is invoked.
    + *
    + * RCU read-side critical sections may be nested. Any deferred actions
    + * will be deferred until the outermost RCU read-side critical section
    + * completes.
    + *
    + * It is illegal to block while in an RCU read-side critical section.
    + */
    +#define rcu_read_lock() __rcu_read_lock()
    +
    +/**
    + * rcu_read_unlock - marks the end of an RCU read-side critical section.
    + *
    + * See rcu_read_lock() for more information.
    + */
    +
    +/*
    + * So where is rcu_write_lock()? It does not exist, as there is no
    + * way for writers to lock out RCU readers. This is a feature, not
    + * a bug -- this property is what provides RCU's performance benefits.
    + * Of course, writers must coordinate with each other. The normal
    + * spinlock primitives work well for this, but any other technique may be
    + * used as well. RCU does not care how the writers keep out of each
    + * others' way, as long as they do so.
    + */
    +#define rcu_read_unlock() __rcu_read_unlock()
    +
    +/**
    + * rcu_read_lock_bh - mark the beginning of a softirq-only RCU critical section
    + *
    + * This is equivalent of rcu_read_lock(), but to be used when updates
    + * are being done using call_rcu_bh(). Since call_rcu_bh() callbacks
    + * consider completion of a softirq handler to be a quiescent state,
    + * a process in RCU read-side critical section must be protected by
    + * disabling softirqs. Read-side critical sections in interrupt context
    + * can use just rcu_read_lock().
    + *
    + */
    +#define rcu_read_lock_bh() __rcu_read_lock_bh()
    +
    +/*
    + * rcu_read_unlock_bh - marks the end of a softirq-only RCU critical section
    + *
    + * See rcu_read_lock_bh() for more information.
    + */
    +#define rcu_read_unlock_bh() __rcu_read_unlock_bh()
    +
    +/**
    + * rcu_read_lock_sched - mark the beginning of a RCU-classic critical section
    + *
    + * Should be used with either
    + * - synchronize_sched()
    + * or
    + * - call_rcu_sched() and rcu_barrier_sched()
    + * on the write-side to insure proper synchronization.
    + */
    +#define rcu_read_lock_sched() preempt_disable()
    +#define rcu_read_lock_sched_notrace() preempt_disable_notrace()
    +
    +/*
    + * rcu_read_unlock_sched - marks the end of a RCU-classic critical section
    + *
    + * See rcu_read_lock_sched for more information.
    + */
    +#define rcu_read_unlock_sched() preempt_enable()
    +#define rcu_read_unlock_sched_notrace() preempt_enable_notrace()
    +
    +
    +
    +/**
    + * rcu_dereference - fetch an RCU-protected pointer in an
    + * RCU read-side critical section. This pointer may later
    + * be safely dereferenced.
    + *
    + * Inserts memory barriers on architectures that require them
    + * (currently only the Alpha), and, more importantly, documents
    + * exactly which pointers are protected by RCU.
    + */
    +
    +#define rcu_dereference(p) ({ \
    + typeof(p) _________p1 = ACCESS_ONCE(p); \
    + smp_read_barrier_depends(); \
    + (_________p1); \
    + })
    +
    +/**
    + * rcu_assign_pointer - assign (publicize) a pointer to a newly
    + * initialized structure that will be dereferenced by RCU read-side
    + * critical sections. Returns the value assigned.
    + *
    + * Inserts memory barriers on architectures that require them
    + * (pretty much all of them other than x86), and also prevents
    + * the compiler from reordering the code that initializes the
    + * structure after the pointer assignment. More importantly, this
    + * call documents which pointers will be dereferenced by RCU read-side
    + * code.
    + */
    +
    +#define rcu_assign_pointer(p, v) \
    + ({ \
    + if (!__builtin_constant_p(v) || \
    + ((v) != NULL)) \
    + smp_wmb(); \
    + (p) = (v); \
    + })
    +
    +#endif /* __LINUX_RCUPDATE_TYPES_H */
    --
    Mathieu Desnoyers
    OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68


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