- 28 Feb, 2010 2 commits
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
Make the holdoff only happen when the full number of attempts have been made. Signed-off-by:
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- 27 Feb, 2010 3 commits
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
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:
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- 26 Feb, 2010 3 commits
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
Change from "unsafe" to "suspicious", given that there will be false alarms. Suggested-by:
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- 25 Feb, 2010 23 commits
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Ingo Molnar authored
I have exported it in d11c563d - 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:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
The spinlocks in rcutree need to be real spinlocks in preempt-rt. Convert them to raw_spinlocks. Signed-off-by:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
The version numbers change too quickly, so use a canonical URL that represents the most recent version. Signed-off-by:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
Signed-off-by:
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Paul E. McKenney authored
Adds a lockdep.txt file and updates checklist.txt and whatisRCU.txt to reflect the new lockdep-enabled capabilities of RCU. Signed-off-by:
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Paul E. McKenney authored
Apply lockdep-ified RCU primitives to key_gc_keyring() and keyring_destroy(). Cc: David Howells <dhowells@redhat.com> Signed-off-by:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
Add lockdep-ified RCU primitives to alloc_fd(), files_fdtable() and fcheck_files(). Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
Update the rcu_dereference() usages to take advantage of the new lockdep-based checking. Signed-off-by:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
Make rcu_dereference_check() print the list of held locks in addition to the stack dump to ease debugging. Signed-off-by:
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Paul E. McKenney authored
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:
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Paul E. McKenney authored
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:
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Ingo Molnar authored
Merge reason: Update from -rc4 to -final. Signed-off-by:
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- 24 Feb, 2010 9 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6Linus Torvalds authored
* 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6: parisc: Set PCI CLS early in boot.
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git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6Linus Torvalds authored
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] Fix broken sn2 build
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Carlos O'Donell authored
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>
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git://git.monstr.eu/linux-2.6-microblazeLinus Torvalds authored
* 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze: microblaze: Fix out_le32() macro microblaze: Fix cache loop function for cache range
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git://git.kernel.dk/linux-2.6-blockLinus Torvalds authored
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: Revert "block: improve queue_should_plug() by looking at IO depths"
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Steven J. Magnani authored
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>
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Michal Simek authored
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: -
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds authored
* 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
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