Commit Graph

180814 Commits (f5f654096487c6d526c47bb66308f9de81f091cf)

Author SHA1 Message Date
Paul E. McKenney f5f6540964 rcu: Export rcu_scheduler_active
Kernel modules using rcu_read_lock_sched_held() must now have
access to rcu_scheduler_active, so it must be exported.

This should fix the fix for the boot-time RCU-lockdep splat.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <20100226030230.GA7743@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-26 08:20:46 +01:00
Paul E. McKenney d9f1bb6ad7 rcu: Make rcu_read_lock_sched_held() take boot time into account
Before the scheduler starts, all tasks are non-preemptible by
definition. So, during that time, rcu_read_lock_sched_held()
needs to always return "true".  This patch makes that be so.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1267135607-7056-2-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-26 08:20:46 +01:00
Paul E. McKenney 056ba4a9be rcu: Make lockdep_rcu_dereference() message less alarmist
Change from "unsafe" to "suspicious", given that there will be
false alarms.

Suggested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1267135607-7056-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-26 08:20:46 +01:00
Ingo Molnar c50cc75271 sched, cgroups: Fix module export
I have exported it in d11c563 - but cgroups.c did not have module.h included ...

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-6-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 12:02:13 +01:00
Paul E. McKenney 1ed509a225 rcu: Add RCU_CPU_STALL_VERBOSE to dump detailed per-task information
When RCU detects a grace-period stall, it currently just prints
out the PID of any tasks doing the stalling.  This patch adds
RCU_CPU_STALL_VERBOSE, which enables the more-verbose reporting
from sched_show_task().

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-21-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:35:02 +01:00
Paul E. McKenney 6155fec92e rcu: Fix rcutorture mod_timer argument to delay one jiffy
The current "mod_timer(&t, 1)" potentially makes the timer fire
immediately, change this to wait one jiffy.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-20-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:35:00 +01:00
Paul E. McKenney 3acd9eb31c rcu: Fix deadlock in TREE_PREEMPT_RCU CPU stall detection
Under TREE_PREEMPT_RCU, print_other_cpu_stall() invokes
rcu_print_task_stall() with the root rcu_node structure's ->lock
held, and rcu_print_task_stall() acquires that same lock for
self-deadlock. Fix this by removing the lock acquisition from
rcu_print_task_stall(), and making all callers acquire the lock
instead.

Tested-by: John Kacur <jkacur@redhat.com>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Located-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-19-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:59 +01:00
Paul E. McKenney 1304afb225 rcu: Convert to raw_spinlocks
The spinlocks in rcutree need to be real spinlocks in
preempt-rt. Convert them to raw_spinlocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-18-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:58 +01:00
Paul E. McKenney 20133cfce7 rcu: Stop overflowing signed integers
The C standard does not specify the result of an operation that
overflows a signed integer, so such operations need to be
avoided.  This patch changes the type of several fields from
"long" to "unsigned long" and adjusts operations as needed.
ULONG_CMP_GE() and ULONG_CMP_LT() macros are introduced to do
the modular comparisons that are appropriate given that overflow
is an expected event.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-17-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:57 +01:00
Paul E. McKenney 1bd22e374b rcu: Use canonical URL for Mathieu's dissertation
The version numbers change too quickly, so use a canonical URL
that represents the most recent version.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-16-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:56 +01:00
Paul E. McKenney 8bd93a2c5d rcu: Accelerate grace period if last non-dynticked CPU
Currently, rcu_needs_cpu() simply checks whether the current CPU
has an outstanding RCU callback, which means that the last CPU
to go into dyntick-idle mode might wait a few ticks for the
relevant grace periods to complete.  However, if all the other
CPUs are in dyntick-idle mode, and if this CPU is in a quiescent
state (which it is for RCU-bh and RCU-sched any time that we are
considering going into dyntick-idle mode), then the grace period
is instantly complete.

This patch therefore repeatedly invokes the RCU grace-period
machinery in order to force any needed grace periods to complete
quickly.  It does so a limited number of times in order to
prevent starvation by an RCU callback function that might pass
itself to call_rcu().

However, if any CPU other than the current one is not in
dyntick-idle mode, fall back to simply checking (with fix to bug
noted by Lai Jiangshan).  Also, take advantage of last
grace-period forcing, the opportunity to do so noted by Steve
Rostedt.  And apply simplified #ifdef condition suggested by
Frederic Weisbecker.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-15-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:55 +01:00
Paul E. McKenney 998f2ac3fe rcu: Fix citation of Mathieu's dissertation
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-14-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:54 +01:00
Paul E. McKenney c598a070bc rcu: Documentation update for CONFIG_PROVE_RCU
Adds a lockdep.txt file and updates checklist.txt and
whatisRCU.txt to reflect the new lockdep-enabled capabilities of
RCU.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-13-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:53 +01:00
Paul E. McKenney e7b0a61b79 security: Apply lockdep-based checking to rcu_dereference() uses
Apply lockdep-ified RCU primitives to key_gc_keyring() and
keyring_destroy().

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-12-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:52 +01:00
Paul E. McKenney 96be753af9 idr: Apply lockdep-based diagnostics to rcu_dereference() uses
Because idr can be used with any of a number of locks or with
any flavor of RCU, just disable the lockdep-based diagnostics.
If idr needs diagnostics, the check expression will need to be
passed into the relevant idr primitives as an additional
argument.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-11-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:51 +01:00
Paul E. McKenney 2676a58c98 radix-tree: Disable RCU lockdep checking in radix tree
Because the radix tree is used with many different locking
designs, we cannot do any effective checking without changing
the radix-tree APIs. It might make sense to do this later, but
only if the RCU lockdep checking proves itself sufficiently
valuable.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-10-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:50 +01:00
Paul E. McKenney af61b96b4f vfs: Abstract rcu_dereference_check for files-fdtable use
Create an rcu_dereference_check_fdtable() that encapsulates the
rcu_dereference_check() condition for fcheck_files() use.  This
has the beneficial side-effect of getting rid of a very long
line.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-9-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:49 +01:00
Paul E. McKenney 7dc5215798 vfs: Apply lockdep-based checking to rcu_dereference() uses
Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable()
and fcheck_files().

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
LKML-Reference: <1266887105-1528-8-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:48 +01:00
Paul E. McKenney 497f0ab39c sched: Better name for for_each_domain_rd
As suggested by Peter Ziljstra, make better choice of name
for for_each_domain_rd(), containing "rcu_dereference", given
that it is but a wrapper for rcu_dereference_check().  The name
rcu_dereference_check_sched_domain() does that and provides a
separate per-subsystem name space.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-7-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:47 +01:00
Paul E. McKenney d11c563dd2 sched: Use lockdep-based checking on rcu_dereference()
Update the rcu_dereference() usages to take advantage of the new
lockdep-based checking.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-6-git-send-email-paulmck@linux.vnet.ibm.com>
[ -v2: fix allmodconfig missing symbol export build failure on x86 ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 10:34:26 +01:00
Paul E. McKenney a898def29e net: Add checking to rcu_dereference() primitives
Update rcu_dereference() primitives to use new lockdep-based
checking. The rcu_dereference() in __in6_dev_get() may be
protected either by rcu_read_lock() or RTNL, per Eric Dumazet.
The rcu_dereference() in __sk_free() is protected by the fact
that it is never reached if an update could change it.  Check
for this by using rcu_dereference_check() to verify that the
struct sock's ->sk_wmem_alloc counter is zero.

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-5-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 09:41:03 +01:00
Paul E. McKenney 3120438ad6 rcu: Disable lockdep checking in RCU list-traversal primitives
The theory is that use of bare rcu_dereference() is more prone
to error than use of the RCU list-traversal primitives.
Therefore, disable lockdep RCU read-side critical-section
checking in these primitives for the time being.  Once all of
the rcu_dereference() uses have been dealt with, it may be time
to re-enable lockdep checking for the RCU list-traversal
primitives.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-4-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 09:41:02 +01:00
Paul E. McKenney 0632eb3d75 rcu: Integrate rcu_dereference_check() message into lockdep
Make rcu_dereference_check() print the list of held locks in
addition to the stack dump to ease debugging.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-3-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 09:41:01 +01:00
Paul E. McKenney c26d34a585 rcu: Add lockdep-enabled variants of rcu_dereference()
Make rcu_dereference() check for being in an RCU read-side
critical section, and create rcu_dereference_bh(),
rcu_dereference_sched(), and srcu_dereference() to check for the
other flavors of RCU.  Also create rcu_dereference_raw() to
avoid checking, and make rcu_dereference_check() use
rcu_dereference_raw().

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-2-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 09:41:00 +01:00
Paul E. McKenney 632ee20013 rcu: Introduce lockdep-based checking to RCU read-side primitives
Inspection is proving insufficient to catch all RCU misuses,
which is understandable given that rcu_dereference() might be
protected by any of four different flavors of RCU (RCU, RCU-bh,
RCU-sched, and SRCU), and might also/instead be protected by any
of a number of locking primitives. It is therefore time to
enlist the aid of lockdep.

This set of patches is inspired by earlier work by Peter
Zijlstra and Thomas Gleixner, and takes the following approach:

o	Set up separate lockdep classes for RCU, RCU-bh, and RCU-sched.

o	Set up separate lockdep classes for each instance of SRCU.

o	Create primitives that check for being in an RCU read-side
	critical section.  These return exact answers if lockdep is
	fully enabled, but if unsure, report being in an RCU read-side
	critical section.  (We want to avoid false positives!)
	The primitives are:

	For RCU: rcu_read_lock_held(void)

	For RCU-bh: rcu_read_lock_bh_held(void)

	For RCU-sched: rcu_read_lock_sched_held(void)

	For SRCU: srcu_read_lock_held(struct srcu_struct *sp)

o	Add rcu_dereference_check(), which takes a second argument
	in which one places a boolean expression based on the above
	primitives and/or lockdep_is_held().

o	A new kernel configuration parameter, CONFIG_PROVE_RCU, enables
	rcu_dereference_check().  This depends on CONFIG_PROVE_LOCKING,
	and should be quite helpful during the transition period while
	CONFIG_PROVE_RCU-unaware patches are in flight.

The existing rcu_dereference() primitive does no checking, but
upcoming patches will change that.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 09:40:59 +01:00
Ingo Molnar 996de8c6fe Merge commit 'v2.6.33' into core/rcu
Merge reason: Update from -rc4 to -final.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25 09:40:26 +01:00
Linus Torvalds 60b341b778 Linux 2.6.33 2010-02-24 10:52:17 -08:00
Linus Torvalds 1e6c5c4e4c Merge branch 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6
* 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6:
  parisc: Set PCI CLS early in boot.
2010-02-24 10:51:21 -08:00
Linus Torvalds 46fe24389a Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] Fix broken sn2 build
2010-02-24 10:51:04 -08:00
Carlos O'Donell 5fd4514bb3 parisc: Set PCI CLS early in boot.
Set the PCI CLS early in the boot process to prevent
device failures. In pcibios_set_master use the new
pci_cache_line_size instead of a hard-coded value.

Signed-off-by: Carlos O'Donell <carlos@codesourcery.com>
Reviewed-by: Grant Grundler <grundler@google.com>
Signed-off-by: Kyle McMartin <kyle@redhat.com>
2010-02-24 17:30:36 +00:00
Linus Torvalds 7b1f94b8a6 Merge branch 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze
* 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Fix out_le32() macro
  microblaze: Fix cache loop function for cache range
2010-02-24 07:43:02 -08:00
Linus Torvalds 83d90addc8 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  Revert "block: improve queue_should_plug() by looking at IO depths"
2010-02-24 07:42:42 -08:00
Steven J. Magnani 83b4d17d88 microblaze: Fix out_le32() macro
Trailing semicolon causes compilation involving out_le32() to fail.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-02-24 13:18:49 +01:00
Michal Simek 0d670b2472 microblaze: Fix cache loop function for cache range
I create wrong asm code but none test shows that this part of code is wrong.
I am not convinces that were good idea to create asm optimized macros
for caches. The reason is that there is not optimization with previous code
that's why make sense to add old code and do some benchmarking which
functions are faster.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-02-24 13:18:29 +01:00
Linus Torvalds 75ef7cdda2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  net: bug fix for vlan + gro issue
  tc35815: Remove a wrong netif_wake_queue() call which triggers BUG_ON
  cdc_ether: new PID for Ericsson C3607w to the whitelist (resubmit)
  IPv6: better document max_addresses parameter
  MAINTAINERS: update mv643xx_eth maintenance status
  e1000: Fix DMA mapping error handling on RX
  iwlwifi: sanity check before counting number of tfds can be free
  iwlwifi: error checking for number of tfds in queue
  iwlwifi: set HT flags after channel in rxon
2010-02-23 19:44:07 -08:00
Ajit Khaparde c4d49794ff net: bug fix for vlan + gro issue
Traffic (tcp) doesnot start on a vlan interface when gro is enabled.
Even the tcp handshake was not taking place.
This is because, the eth_type_trans call before the netif_receive_skb
in napi_gro_finish() resets the skb->dev to napi->dev from the previously
set vlan netdev interface. This causes the ip_route_input to drop the
incoming packet considering it as a packet coming from a martian source.

I could repro this on 2.6.32.7 (stable) and 2.6.33-rc7.
With this fix, the traffic starts and the test runs fine on both vlan
and non-vlan interfaces.

CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: Ajit Khaparde <ajitk@serverengines.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-23 19:09:31 -08:00
Linus Torvalds be64c970f6 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  ACPI: Be in TS_POLLING state during mwait based C-state entry
  ACPI: Fix regression where _PPC is not read at boot even when ignore_ppc=0
  acer-wmi: Respect current backlight level when loading
2010-02-23 18:15:05 -08:00
Linus Torvalds 34e3f91b4e Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/vmwgfx: Fix queries if no dma buffer thrashing is occuring.
  drm/nv50: fix vram ptes on IGPs to point at stolen system memory
  drm/nv50: fix instmem binding on IGPs to point at stolen system memory
  drm/nv50: improve vram page table construction
  drm/nv50: more efficient clearing of gpu page table entries
  drm/nv50: make nv50_mem_vm_{bind,unbind} operate only on vram
  drm/nouveau: Fix up pre-nv17 analog load detection.
2010-02-23 18:13:34 -08:00
Hedi Berriche f7624c97b8 [IA64] Fix broken sn2 build
Revert the change made to arch/ia64/sn/kernel/setup.c by commit
204fba4aa3 as it breaks the build.

Fixing the build the b94b08081f way
breaks xpc because genksyms then fails to generate an CRC for
per_cpu____sn_cnodeid_to_nasid because of limitations in the
generic genksyms code.

Signed-off-by: Hedi Berriche <hedi@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2010-02-23 16:07:25 -08:00
David S. Miller 675c60706c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2010-02-23 01:27:05 -08:00
Atsushi Nemoto 662a96bd6f tc35815: Remove a wrong netif_wake_queue() call which triggers BUG_ON
The netif_wake_queue() is called correctly (i.e. only on !txfull
condition) from txdone routine.  So Unconditional call to the
netif_wake_queue() here is wrong.  This might cause calling of
start_xmit routine on txfull state and trigger BUG_ON.

This bug does not happen when NAPI disabled.  After txdone there
must be at least one free tx slot.  But with NAPI, this is not
true anymore and the BUG_ON can hits on heavy load.

In this driver NAPI was enabled on 2.6.33-rc1 so this is
regression from 2.6.32 kernel.

Reported-by: Ralf Roesch <ralf.roesch@rw-gmbh.de>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-23 01:25:01 -08:00
Torgny Johansson cac43a1b7b cdc_ether: new PID for Ericsson C3607w to the whitelist (resubmit)
This patch adds a new vid/pid to the cdc_ether whitelist.

Device added:
- Ericsson Mobile Broadband variant C3607w

Signed-off-by: Torgny Johansson <torgny.johansson@gmail.com>

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Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-23 01:25:01 -08:00
Brian Haley e79dc48431 IPv6: better document max_addresses parameter
Andrew Morton wrote:
>> >From ip-sysctl.txt file in kernel documentation I can see following description
>> for max_addresses:
>> max_addresses - INTEGER
>>         Number of maximum addresses per interface.  0 disables limitation.
>>         It is recommended not set too large value (or 0) because it would
>>         be too easy way to crash kernel to allow to create too much of
>>         autoconfigured addresses.
           ^^^^^^^^^^^^^^

>> If this parameter applies only for auto-configured IP addressed, please state
>> it more clearly in docs or rename the parameter to show that it refers to
>> auto-configuration.

It did mention autoconfigured in the text, but the below makes it more obvious.

More clearly document IPv6 max_addresses parameter.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-23 01:25:00 -08:00
Lennert Buytenhek f5ca8502f7 MAINTAINERS: update mv643xx_eth maintenance status
I am no longer with Marvell.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-23 01:25:00 -08:00
Anton Blanchard b5abb028e2 e1000: Fix DMA mapping error handling on RX
Check for error return from pci_map_single/pci_map_page and clean up.

With this and the previous patch the driver was able to handle a significant
percentage of errors (I set the fault injection rate to 10% and could still
download large files at a reasonable speed).

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-23 01:24:59 -08:00
Jens Axboe 79da0644a8 Revert "block: improve queue_should_plug() by looking at IO depths"
This reverts commit fb1e75389b.

"Benjamin S." <sbenni@gmx.de> reports that the patch in question
causes a big drop in sequential throughput for him, dropping from
200MB/sec down to only 70MB/sec.

Needs to be investigated more fully, for now lets just revert the
offending commit.

Conflicts:

	include/linux/blkdev.h

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-02-23 08:40:43 +01:00
Thomas Hellstrom 4e4ddd4777 drm/vmwgfx: Fix queries if no dma buffer thrashing is occuring.
Intercept query commands and apply relocations to their guest pointers.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-02-23 15:42:36 +10:00
Dave Airlie f7072e00f0 Merge remote branch 'nouveau/for-airlied' of ../drm-nouveau-next into drm-linus
* 'nouveau/for-airlied' of ../drm-nouveau-next:
  drm/nv50: fix vram ptes on IGPs to point at stolen system memory
  drm/nv50: fix instmem binding on IGPs to point at stolen system memory
  drm/nv50: improve vram page table construction
  drm/nv50: more efficient clearing of gpu page table entries
  drm/nv50: make nv50_mem_vm_{bind,unbind} operate only on vram
  drm/nouveau: Fix up pre-nv17 analog load detection.
2010-02-23 15:42:18 +10:00
Len Brown b2cb9dcb98 Merge branch 'pcc' into release 2010-02-23 00:39:00 -05:00
Len Brown e4f23f66ed Merge branches 'bugzilla-14207' and 'idle' into release 2010-02-23 00:19:48 -05:00