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* rcu: Make task_subsys_state() RCU-lockdep checks handle boot-time usePaul E. McKenney2010-02-28
| | | | | | | | | | | | | | | | | | | | | | | | It is apparently legal to invoke task_subsys_state() without RCU protection during early boot time. After all, there are no concurrent tasks, so there can be no grace periods completing concurrently. But this does need an Acked-by from the cgroups folks. Located-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: <1267311188-16603-2-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu: Fix holdoff for accelerated GPs for last non-dynticked CPUPaul E. McKenney2010-02-28
| | | | | | | | | | | | | | | | | | | Make the holdoff only happen when the full number of attempts have been made. 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: <1267311188-16603-1-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu: Fix accelerated GPs for last non-dynticked CPUPaul E. McKenney2010-02-27
| | | | | | | | | | | | | | | | | | | | | This patch disables irqs across the call to rcu_needs_cpu(). It also enforces a hold-off period so that the idle loop doesn't softirq itself to death when there are lots of RCU callbacks in flight on the last non-dynticked CPU. 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: <1267231138-27856-3-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu: Make non-RCU_PROVE_LOCKING rcu_read_lock_sched_held() understand bootPaul E. McKenney2010-02-27
| | | | | | | | | | | | | | | | | | | | | 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 for RCU_PROVE_LOCKING=n. 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: <1267231138-27856-2-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu: Fix accelerated grace periods for last non-dynticked CPUPaul E. McKenney2010-02-27
| | | | | | | | | | | | | | | | | | | | | | It is invalid to invoke __rcu_process_callbacks() with irqs disabled, so do it indirectly via raise_softirq(). This requires a state-machine implementation to cycle through the grace-period machinery the required number of times. Located-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: <1267231138-27856-1-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* rcu: Export rcu_scheduler_activePaul E. McKenney2010-02-26
| | | | | | | | | | | | | | | | | | | | | 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>
* rcu: Make rcu_read_lock_sched_held() take boot time into accountPaul E. McKenney2010-02-26
| | | | | | | | | | | | | | | | | | | | 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>
* rcu: Make lockdep_rcu_dereference() message less alarmistPaul E. McKenney2010-02-26
| | | | | | | | | | | | | | | | | | | | 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>
* sched, cgroups: Fix module exportIngo Molnar2010-02-25
| | | | | | | | | | | | | | | | | | 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>
* rcu: Add RCU_CPU_STALL_VERBOSE to dump detailed per-task informationPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | 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>
* rcu: Fix rcutorture mod_timer argument to delay one jiffyPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | 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>
* rcu: Fix deadlock in TREE_PREEMPT_RCU CPU stall detectionPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* rcu: Convert to raw_spinlocksPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | 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>
* rcu: Stop overflowing signed integersPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* rcu: Use canonical URL for Mathieu's dissertationPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | 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>
* rcu: Accelerate grace period if last non-dynticked CPUPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* rcu: Fix citation of Mathieu's dissertationPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | 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>
* rcu: Documentation update for CONFIG_PROVE_RCUPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | 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>
* security: Apply lockdep-based checking to rcu_dereference() usesPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | 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>
* idr: Apply lockdep-based diagnostics to rcu_dereference() usesPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | 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>
* radix-tree: Disable RCU lockdep checking in radix treePaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | 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>
* vfs: Abstract rcu_dereference_check for files-fdtable usePaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | 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>
* vfs: Apply lockdep-based checking to rcu_dereference() usesPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | 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>
* sched: Better name for for_each_domain_rdPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | 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>
* sched: Use lockdep-based checking on rcu_dereference()Paul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | 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>
* net: Add checking to rcu_dereference() primitivesPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* rcu: Disable lockdep checking in RCU list-traversal primitivesPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* rcu: Integrate rcu_dereference_check() message into lockdepPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | 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>
* rcu: Add lockdep-enabled variants of rcu_dereference()Paul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* rcu: Introduce lockdep-based checking to RCU read-side primitivesPaul E. McKenney2010-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge commit 'v2.6.33' into core/rcuIngo Molnar2010-02-25
|\ | | | | | | | | | | Merge reason: Update from -rc4 to -final. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * Linux 2.6.33v2.6.33Linus Torvalds2010-02-24
| |
| * Merge branch 'urgent' of ↵Linus Torvalds2010-02-24
| |\ | | | | | | | | | | | | | | | | | | 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.
| | * parisc: Set PCI CLS early in boot.Carlos O'Donell2010-02-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | Merge branch 'release' of ↵Linus Torvalds2010-02-24
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | 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
| | * | [IA64] Fix broken sn2 buildHedi Berriche2010-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revert the change made to arch/ia64/sn/kernel/setup.c by commit 204fba4aa303ea4a7bb726a539bf4a5b9e3203d0 as it breaks the build. Fixing the build the b94b08081fcecf83fa690d6c5664f6316fe72208 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>
| * | | Merge branch 'for-linus' of git://git.monstr.eu/linux-2.6-microblazeLinus Torvalds2010-02-24
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze: microblaze: Fix out_le32() macro microblaze: Fix cache loop function for cache range
| | * | | microblaze: Fix out_le32() macroSteven J. Magnani2010-02-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * | | microblaze: Fix cache loop function for cache rangeMichal Simek2010-02-24
| | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2010-02-24
| |\ \ \ | | |/ / | |/| | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: Revert "block: improve queue_should_plug() by looking at IO depths"
| | * | Revert "block: improve queue_should_plug() by looking at IO depths"Jens Axboe2010-02-23
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit fb1e75389bd06fd5987e9cda1b4e0305c782f854. "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>
| * | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds2010-02-23
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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
| | * | net: bug fix for vlan + gro issueAjit Khaparde2010-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * | Merge branch 'master' of ↵David S. Miller2010-02-23
| | |\ \ | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6
| | | * | iwlwifi: sanity check before counting number of tfds can be freeStanislaw Gruszka2010-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Check the frame control for ieee80211_is_data_qos() is true before counting the number of tfds can be free, the tfds_in_queue only increment when ieee80211_is_data_qos() is true before transmit; so it should only decrement if the type match. Remove ieee80211_is_data_qos check for frame_ctrl in tx_resp to avoid invalid information pass from uCode. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> CC: stable@kernel.org Signed-off-by: John W. Linville <linville@tuxdriver.com>
| | | * | iwlwifi: error checking for number of tfds in queueWey-Yi Guy2010-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When receive reply_tx and ready to decrement the count for number of tfds in queue, do error checking to prevent error condition and tfds_in_queue become negative number. Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> CC: stable@kernel.org Signed-off-by: John W. Linville <linville@tuxdriver.com>
| | | * | iwlwifi: set HT flags after channel in rxonDan Halperin2010-02-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The HT extension channel settings require priv->staging_rxon.channel to be accurate. However, iwl_set_rxon_ht was being called before iwl_set_rxon_channel and thus HT40 could be broken unless another call to iwl_mac_config came in. This problem was recently introduced by "iwlwifi: Fix to set correct ht configuration" The particular setting in which I noticed this was monitor mode: iwconfig wlan0 mode monitor ifconfig wlan0 up ./iw wlan0 set channel 64 HT40- #./iw wlan0 set channel 64 HT40- tcpdump -i wlan0 -y IEEE802_11_RADIO would only catch HT40 packets if I issued the IW command twice. From visual inspection, iwl_set_rxon_channel does not depend on iwl_set_rxon_ht, so simply swapping them should be safe and fixes this problem. Signed-off-by: Daniel Halperin <dhalperi@cs.washington.edu> Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> CC: stable@kernel.org Signed-off-by: John W. Linville <linville@tuxdriver.com>
| | * | | tc35815: Remove a wrong netif_wake_queue() call which triggers BUG_ONAtsushi Nemoto2010-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| | * | | cdc_ether: new PID for Ericsson C3607w to the whitelist (resubmit)Torgny Johansson2010-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Signed-off-by: David S. Miller <davem@davemloft.net>
| | * | | IPv6: better document max_addresses parameterBrian Haley2010-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>