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* Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds2012-05-2123-353/+1358
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU changes from Ingo Molnar: "This is the v3.5 RCU tree from Paul E. McKenney: 1) A set of improvements and fixes to the RCU_FAST_NO_HZ feature (with more on the way for 3.6). Posted to LKML: https://lkml.org/lkml/2012/4/23/324 (commits 1-3 and 5), https://lkml.org/lkml/2012/4/16/611 (commit 4), https://lkml.org/lkml/2012/4/30/390 (commit 6), and https://lkml.org/lkml/2012/5/4/410 (commit 7, combined with the other commits for the convenience of the tester). 2) Changes to make rcu_barrier() avoid disrupting execution of CPUs that have no RCU callbacks. Posted to LKML: https://lkml.org/lkml/2012/4/23/322. 3) A couple of commits that improve the efficiency of the interaction between preemptible RCU and the scheduler, these two being all that survived an abortive attempt to allow preemptible RCU's __rcu_read_lock() to be inlined. The full set was posted to LKML at https://lkml.org/lkml/2012/4/14/143, and the first and third patches of that set remain. 4) Lai Jiangshan's algorithmic implementation of SRCU, which includes call_srcu() and srcu_barrier(). A major feature of this new implementation is that synchronize_srcu() no longer disturbs the execution of other CPUs. This work is based on earlier implementations by Peter Zijlstra and Paul E. McKenney. Posted to LKML: https://lkml.org/lkml/2012/2/22/82. 5) A number of miscellaneous bug fixes and improvements which were posted to LKML at: https://lkml.org/lkml/2012/4/23/353 with subsequent updates posted to LKML." * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) rcu: Make rcu_barrier() less disruptive rcu: Explicitly initialize RCU_FAST_NO_HZ per-CPU variables rcu: Make RCU_FAST_NO_HZ handle timer migration rcu: Update RCU maintainership rcu: Make exit_rcu() more precise and consolidate rcu: Move PREEMPT_RCU preemption to switch_to() invocation rcu: Ensure that RCU_FAST_NO_HZ timers expire on correct CPU rcu: Add rcutorture test for call_srcu() rcu: Implement per-domain single-threaded call_srcu() state machine rcu: Use single value to handle expedited SRCU grace periods rcu: Improve srcu_readers_active_idx()'s cache locality rcu: Remove unused srcu_barrier() rcu: Implement a variant of Peter's SRCU algorithm rcu: Improve SRCU's wait_idx() comments rcu: Flip ->completed only once per SRCU grace period rcu: Increment upper bit only for srcu_read_lock() rcu: Remove fast check path from __synchronize_srcu() rcu: Direct algorithmic SRCU implementation rcu: Introduce rcutorture testing for rcu_barrier() timer: Fix mod_timer_pinned() header comment ...
| * Merge branch 'rcu/next' of ↵Ingo Molnar2012-05-1423-353/+1358
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull the v3.5 RCU tree from Paul E. McKenney: 1) A set of improvements and fixes to the RCU_FAST_NO_HZ feature (with more on the way for 3.6). Posted to LKML: https://lkml.org/lkml/2012/4/23/324 (commits 1-3 and 5), https://lkml.org/lkml/2012/4/16/611 (commit 4), https://lkml.org/lkml/2012/4/30/390 (commit 6), and https://lkml.org/lkml/2012/5/4/410 (commit 7, combined with the other commits for the convenience of the tester). 2) Changes to make rcu_barrier() avoid disrupting execution of CPUs that have no RCU callbacks. Posted to LKML: https://lkml.org/lkml/2012/4/23/322. 3) A couple of commits that improve the efficiency of the interaction between preemptible RCU and the scheduler, these two being all that survived an abortive attempt to allow preemptible RCU's __rcu_read_lock() to be inlined. The full set was posted to LKML at https://lkml.org/lkml/2012/4/14/143, and the first and third patches of that set remain. 4) Lai Jiangshan's algorithmic implementation of SRCU, which includes call_srcu() and srcu_barrier(). A major feature of this new implementation is that synchronize_srcu() no longer disturbs the execution of other CPUs. This work is based on earlier implementations by Peter Zijlstra and Paul E. McKenney. Posted to LKML: https://lkml.org/lkml/2012/2/22/82. 5) A number of miscellaneous bug fixes and improvements which were posted to LKML at: https://lkml.org/lkml/2012/4/23/353 with subsequent updates posted to LKML. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | *---. Merge branches 'barrier.2012.05.09a', 'fixes.2012.04.26a', ↵Paul E. McKenney2012-05-1121-237/+1035
| | |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'inline.2012.05.02b' and 'srcu.2012.05.07b' into HEAD barrier: Reduce the amount of disturbance by rcu_barrier() to the rest of the system. This branch also includes improvements to RCU_FAST_NO_HZ, which are included here due to conflicts. fixes: Miscellaneous fixes. inline: Remaining changes from an abortive attempt to inline preemptible RCU's __rcu_read_lock(). These are (1) making exit_rcu() avoid unnecessary work and (2) avoiding having preemptible RCU record a blocked thread when the scheduler declines to do a context switch. srcu: Lai Jiangshan's algorithmic implementation of SRCU, including call_srcu().
| | | | | * rcu: Update RCU maintainershipPaul E. McKenney2012-05-071-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split SRCU out and add Lai Jiangshan as SRCU co-maintainer. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Add rcutorture test for call_srcu()Lai Jiangshan2012-04-301-4/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add srcu_torture_deferred_free() for srcu_ops so as to test the new call_srcu(). Rename the original srcu_ops to srcu_sync_ops. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Implement per-domain single-threaded call_srcu() state machineLai Jiangshan2012-04-302-63/+336
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit implements an SRCU state machine in support of call_srcu(). The state machine is preemptible, light-weight, and single-threaded, minimizing synchronization overhead. In particular, there is no longer any need for synchronize_srcu() to be guarded by a mutex. Expedited processing is handled, at least in the absence of concurrent grace-period operations on that same srcu_struct structure, by having the synchronize_srcu_expedited() thread take on the role of the workqueue thread for one iteration. There is a reasonable probability that a given SRCU callback will be invoked on the same CPU that registered it, however, there is no guarantee. Concurrent SRCU grace-period primitives can cause callbacks to be executed elsewhere, even in absence of CPU-hotplug operations. Callbacks execute in process context, but under the influence of local_bh_disable(), so it is illegal to sleep in an SRCU callback function. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Use single value to handle expedited SRCU grace periodsLai Jiangshan2012-04-301-13/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The earlier algorithm used an "expedited" flag combined with a "trycount" counter to differentiate between normal and expedited SRCU grace periods. However, the difference can be encoded into a single counter with a cutoff value and different initial values for expedited and normal SRCU grace periods. This commit makes that change. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Conflicts: kernel/srcu.c
| | | | | * rcu: Improve srcu_readers_active_idx()'s cache localityLai Jiangshan2012-04-301-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Expand the calls to srcu_readers_active_idx() from srcu_readers_active() inline. This change improves cache locality by interating over the CPUs once rather than twice. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Remove unused srcu_barrier()Lai Jiangshan2012-04-301-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The old srcu_barrier() macro is now unused. This commit removes it so that it may be used for the SRCU flavor of rcu_barrier(), which will in turn be needed to allow the upcoming call_srcu() to be used from within modules. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Implement a variant of Peter's SRCU algorithmLai Jiangshan2012-04-302-86/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit implements a variant of Peter's algorithm, which may be found at https://lkml.org/lkml/2012/2/1/119. o Make the checking lock-free to enable parallel checking. Parallel checking is required when (1) the original checking task is preempted for a long time, (2) sychronize_srcu_expedited() starts during an ongoing SRCU grace period, or (3) we wish to avoid acquiring a lock. o Since the checking is lock-free, we avoid a mutex in state machine for call_srcu(). o Remove the SRCU_REF_MASK and remove the coupling with the flipping. This might allow us to remove the preempt_disable() in future versions, though such removal will need great care because it rescinds the one-old-reader-per-CPU guarantee. o Remove a smp_mb(), simplify the comments and make the smp_mb() pairs more intuitive. Inspired-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Improve SRCU's wait_idx() commentsLai Jiangshan2012-04-301-40/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The safety of SRCU is provided byy wait_idx() rather than flipping. The flipping actually prevents starvation. This commit therefore updates the comments to more accurately and precisely describe what is going on. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Flip ->completed only once per SRCU grace periodLai Jiangshan2012-04-301-36/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is an optimization of the SRCU grace period. To guard against preempted readers with old values of the counter, it suffices to scan the old counters once more, then flip ->completed only one time. The reason this works is that the old readers must have incremented the old set of counters (if they have not yet incremented, then their critical section starts after this grace period, so they may be safely ignored). This commit therefore optimizes the second flip out in favor of a simple rescan. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Increment upper bit only for srcu_read_lock()Lai Jiangshan2012-04-302-11/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The purpose of the upper bit of SRCU's per-CPU counters is to guarantee that no reasonable series of srcu_read_lock() and srcu_read_unlock() operations can return the value of the counter to its original value. This guarantee is require only after the index has been switched to the other set of counters, so at most one srcu_read_lock() can affect a given CPU's counter. The number of srcu_read_unlock() operations on a given counter is limited to the number of tasks in the system, which given the Linux kernel's current structure is limited to far less than 2^30 on 32-bit systems and far less than 2^62 on 64-bit systems. (Something about a limited number of bytes in the kernel's address space.) Therefore, if srcu_read_lock() increments the upper bits, then srcu_read_unlock() need not do so. In this case, an srcu_read_lock() and an srcu_read_unlock() will flip the lower bit of the upper field of the counter. An unreasonably large additional number of srcu_read_unlock() operations would be required to return the counter to its initial value, thus preserving the guarantee. This commit takes this approach, which further allows it to shrink the size of the upper field to one bit, making the number of srcu_read_unlock() operations required to return the counter to its initial value even more unreasonable than before. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Remove fast check path from __synchronize_srcu()Lai Jiangshan2012-04-301-24/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The fastpath in __synchronize_srcu() is designed to handle cases where there are a large number of concurrent calls for the same srcu_struct structure. However, the Linux kernel currently does not use SRCU in this manner, so remove the fastpath checks for simplicity. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Direct algorithmic SRCU implementationPaul E. McKenney2012-04-303-98/+198
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current implementation of synchronize_srcu_expedited() can cause severe OS jitter due to its use of synchronize_sched(), which in turn invokes try_stop_cpus(), which causes each CPU to be sent an IPI. This can result in severe performance degradation for real-time workloads and especially for short-interation-length HPC workloads. Furthermore, because only one instance of try_stop_cpus() can be making forward progress at a given time, only one instance of synchronize_srcu_expedited() can make forward progress at a time, even if they are all operating on distinct srcu_struct structures. This commit, inspired by an earlier implementation by Peter Zijlstra (https://lkml.org/lkml/2012/1/31/211) and by further offline discussions, takes a strictly algorithmic bits-in-memory approach. This has the disadvantage of requiring one explicit memory-barrier instruction in each of srcu_read_lock() and srcu_read_unlock(), but on the other hand completely dispenses with OS jitter and furthermore allows SRCU to be used freely by CPUs that RCU believes to be idle or offline. The update-side implementation handles the single read-side memory barrier by rechecking the per-CPU counters after summing them and by running through the update-side state machine twice. This implementation has passed moderate rcutorture testing on both x86 and Power. Also updated to use this_cpu_ptr() instead of per_cpu_ptr(), as suggested by Peter Zijlstra. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
| | | | | * rcu: Introduce rcutorture testing for rcu_barrier()Paul E. McKenney2012-04-302-9/+200
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although rcutorture does invoke rcu_barrier() and friends, it cannot really be called a torture test given that it invokes them only once at the end of the test. This commit therefore introduces heavy-duty rcutorture testing for rcu_barrier(), which may be carried out concurrently with normal rcutorture testing. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | | * rcu: Fixes to rcutorture error handling and cleanupPaul E. McKenney2012-04-241-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The rcutorture initialization code ignored the error returns from rcu_torture_onoff_init() and rcu_torture_stall_init(). The rcutorture cleanup code failed to NULL out a number of pointers. These bugs will normally have no effect, but this commit fixes them nevertheless. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | | * | rcu: Make exit_rcu() more precise and consolidatePaul E. McKenney2012-05-026-49/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running preemptible RCU, if a task exits in an RCU read-side critical section having blocked within that same RCU read-side critical section, the task must be removed from the list of tasks blocking a grace period (perhaps the current grace period, perhaps the next grace period, depending on timing). The exit() path invokes exit_rcu() to do this cleanup. However, the current implementation of exit_rcu() needlessly does the cleanup even if the task did not block within the current RCU read-side critical section, which wastes time and needlessly increases the size of the state space. Fix this by only doing the cleanup if the current task is actually on the list of tasks blocking some grace period. While we are at it, consolidate the two identical exit_rcu() functions into a single function. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Linus Torvalds <torvalds@linux-foundation.org> Conflicts: kernel/rcupdate.c
| | | | * | rcu: Move PREEMPT_RCU preemption to switch_to() invocationPaul E. McKenney2012-05-028-19/+16
| | | | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, PREEMPT_RCU readers are enqueued upon entry to the scheduler. This is inefficient because enqueuing is required only if there is a context switch, and entry to the scheduler does not guarantee a context switch. The commit therefore moves the enqueuing to immediately precede the call to switch_to() from the scheduler. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
| | | * | timer: Fix mod_timer_pinned() header commentPaul E. McKenney2012-04-261-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The mod_timer_pinned() header comment states that it prevents timers from being migrated to a different CPU. This is not the case, instead, it ensures that the timer is posted to the current CPU, but does nothing to prevent CPU-hotplug operations from migrating the timer. This commit therefore brings the comment header into alignment with reality. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org>
| | | * | rcu: Document why rcu_blocking_is_gp() is safePaul E. McKenney2012-04-242-7/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The rcu_blocking_is_gp() function tests to see if there is only one online CPU, and if so, synchronize_sched() and friends become no-ops. However, for larger systems, num_online_cpus() scans a large vector, and might be preempted while doing so. While preempted, any number of CPUs might come online and go offline, potentially resulting in num_online_cpus() returning 1 when there never had only been one CPU online. This could result in a too-short RCU grace period, which could in turn result in total failure, except that the only way that the grace period is too short is if there is an RCU read-side critical section spanning it. For RCU-sched and RCU-bh (which are the only cases using rcu_blocking_is_gp()), RCU read-side critical sections have either preemption or bh disabled, which prevents CPUs from going offline. This in turn prevents actual failures from occurring. This commit therefore adds a large block comment to rcu_blocking_is_gp() documenting why it is safe. This commit also moves rcu_blocking_is_gp() into kernel/rcutree.c, which should help prevent unwary developers from mistaking it for a generally useful function. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: Document kernel command-line parametersPaul E. McKenney2012-04-241-3/+85
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bring RCU's kernel command-line parameter documentation up to date. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: Reduce cache-miss initialization latencies for large systemsPaul E. McKenney2012-04-243-8/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit #0209f649 (rcu: limit rcu_node leaf-level fanout) set an upper limit of 16 on the leaf-level fanout for the rcu_node tree. This was needed to reduce lock contention that was induced by the synchronization of scheduling-clock interrupts, which was in turn needed to improve energy efficiency for moderate-sized lightly loaded servers. However, reducing the leaf-level fanout means that there are more leaf-level rcu_node structures in the tree, which in turn means that RCU's grace-period initialization incurs more cache misses. This is not a problem on moderate-sized servers with only a few tens of CPUs, but becomes a major source of real-time latency spikes on systems with many hundreds of CPUs. In addition, the workloads running on these large systems tend to be CPU-bound, which eliminates the energy-efficiency advantages of synchronizing scheduling-clock interrupts. Therefore, these systems need maximal values for the rcu_node leaf-level fanout. This commit addresses this problem by introducing a new kernel parameter named RCU_FANOUT_LEAF that directly controls the leaf-level fanout. This parameter defaults to 16 to handle the common case of a moderate sized lightly loaded servers, but may be set higher on larger systems. Reported-by: Mike Galbraith <efault@gmx.de> Reported-by: Dimitri Sivanich <sivanich@sgi.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: Make __kfree_rcu() less dependent on compiler choicesJan Engelhardt2012-04-241-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, __kfree_rcu() is implemented as an inline function, and contains a BUILD_BUG_ON() that malfunctions if __kfree_rcu() is compiled as an out-of-line function. Unfortunately, there are compiler settings (e.g., -O0) that can result in __kfree_rcu() being compiled out of line, resulting in annoying build breakage. This commit therefore converts both __kfree_rcu() and __is_kfree_rcu_offset() from inline functions to macros to prevent such misbehavior on the part of the compiler. Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
| | | * | rcu: Clarify help text for RCU_BOOST_PRIOPaul E. McKenney2012-04-241-4/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The old text confused real-time applications with real-time threads, so that you pretty much needed to understand how this kernel configuration parameter worked to understand the help text. This commit therefore attempts to make the help text human-readable. Reported-by: Jörn Engel <joern@purestorage.com> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: Replace list_first_entry_rcu() with list_first_or_null_rcu()Michel Machado2012-04-241-4/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The list_first_entry_rcu() macro is inherently unsafe because it cannot be applied to an empty list. But because RCU readers do not exclude updaters, a list might become empty between the time that list_empty() claimed it was non-empty and the time that list_first_entry_rcu() is invoked. Therefore, the list_empty() test cannot be separated from the list_first_entry_rcu() call. This commit therefore combines these to macros to create a new list_first_or_null_rcu() macro that replaces the old (and unsafe) list_first_entry_rcu() macro. This patch incorporates Paul's review comments on the previous version of this patch available here: https://lkml.org/lkml/2012/4/2/536 This patch cannot break any upstream code because list_first_entry_rcu() is not being used anywhere in the kernel (tested with grep(1)), and any external code using it is probably broken as a result of using it. Signed-off-by: Michel Machado <michel@digirati.com.br> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | | * | rcu: List-debug variants of rcu list routines.Dave Jones2012-04-242-1/+28
| | | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Make __list_add_rcu check the next->prev and prev->next pointers just like __list_add does. * Make list_del_rcu use __list_del_entry, which does the same checking at deletion time. Has been running for a week here without anything being tripped up, but it seems worth adding for completeness just in case something ever does corrupt those lists. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Make rcu_barrier() less disruptivePaul E. McKenney2012-05-093-88/+222
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The rcu_barrier() primitive interrupts each and every CPU, registering a callback on every CPU. Once all of these callbacks have been invoked, rcu_barrier() knows that every callback that was registered before the call to rcu_barrier() has also been invoked. However, there is no point in registering a callback on a CPU that currently has no callbacks, most especially if that CPU is in a deep idle state. This commit therefore makes rcu_barrier() avoid interrupting CPUs that have no callbacks. Doing this requires reworking the handling of orphaned callbacks, otherwise callbacks could slip through rcu_barrier()'s net by being orphaned from a CPU that rcu_barrier() had not yet interrupted to a CPU that rcu_barrier() had already interrupted. This reworking was needed anyway to take a first step towards weaning RCU from the CPU_DYING notifier's use of stop_cpu(). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Explicitly initialize RCU_FAST_NO_HZ per-CPU variablesPaul E. McKenney2012-05-091-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current initialization of the RCU_FAST_NO_HZ per-CPU variables makes needless and fragile assumptions about the initial value of things like the jiffies counter. This commit therefore explicitly initializes all of them that are better started with a non-zero value. It also adds some comments describing the per-CPU state variables. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Make RCU_FAST_NO_HZ handle timer migrationPaul E. McKenney2012-05-092-3/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current RCU_FAST_NO_HZ assumes that timers do not migrate unless a CPU goes offline, in which case it assumes that the CPU will have to come out of dyntick-idle mode (cancelling the timer) in order to go offline. This is important because when RCU_FAST_NO_HZ permits a CPU to enter dyntick-idle mode despite having RCU callbacks pending, it posts a timer on that CPU to force a wakeup on that CPU. This wakeup ensures that the CPU will eventually handle the end of the grace period, including invoking its RCU callbacks. However, Pascal Chapperon's test setup shows that the timer handler rcu_idle_gp_timer_func() really does get invoked in some cases. This is problematic because this can cause the CPU that entered dyntick-idle mode despite still having RCU callbacks pending to remain in dyntick-idle mode indefinitely, which means that its RCU callbacks might never be invoked. This situation can result in grace-period delays or even system hangs, which matches Pascal's observations of slow boot-up and shutdown (https://lkml.org/lkml/2012/4/5/142). See also the bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=806548 This commit therefore causes the "should never be invoked" timer handler rcu_idle_gp_timer_func() to use smp_call_function_single() to wake up the CPU for which the timer was intended, allowing that CPU to invoke its RCU callbacks in a timely manner. Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Ensure that RCU_FAST_NO_HZ timers expire on correct CPUPaul E. McKenney2012-05-011-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Timers are subject to migration, which can lead to the following system-hang scenario when CONFIG_RCU_FAST_NO_HZ=y: 1. CPU 0 executes synchronize_rcu(), which posts an RCU callback. 2. CPU 0 then goes idle. It cannot immediately invoke the callback, but there is nothing RCU needs from ti, so it enters dyntick-idle mode after posting a timer. 3. The timer gets migrated to CPU 1. 4. CPU 0 never wakes up, so the synchronize_rcu() never returns, so the system hangs. This commit fixes this problem by using mod_timer_pinned(), as suggested by Peter Zijlstra, to ensure that the timer is actually posted on the running CPU. Reported-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Add warning for RCU_FAST_NO_HZ timer firingPaul E. McKenney2012-04-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RCU_FAST_NO_HZ uses a timer to limit the time that a CPU with callbacks can remain in dyntick-idle mode. This timer is cancelled when the CPU exits idle, and therefore should never fire. However, if the timer were migrated to some other CPU for whatever reason (1) the timer could actually fire and (2) firing on some other CPU would fail to wake up the CPU with callbacks, possibly resulting in sluggishness or a system hang. This commit therfore adds a WARN_ON_ONCE() to the timer handler in order to detect this condition. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Make RCU_FAST_NO_HZ account for pauses out of idlePaul E. McKenney2012-04-243-4/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both Steven Rostedt's new idle-capable trace macros and the RCU_NONIDLE() macro can cause RCU to momentarily pause out of idle without the rest of the system being involved. This can cause rcu_prepare_for_idle() to run through its state machine too quickly, which can in turn result in needless scheduling-clock interrupts. This commit therefore adds code to enable rcu_prepare_for_idle() to distinguish between an initial entry to idle on the one hand (which needs to advance the rcu_prepare_for_idle() state machine) and an idle reentry due to idle-capable trace macros and RCU_NONIDLE() on the other hand (which should avoid advancing the rcu_prepare_for_idle() state machine). Additional state is maintained to allow the timer to be correctly reposted when returning after a momentary pause out of idle, and even more state is maintained to detect when new non-lazy callbacks have been enqueued (which may require re-evaluation of the approach to idleness). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Make RCU_FAST_NO_HZ use timer rather than hrtimerPaul E. McKenney2012-04-241-28/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The RCU_FAST_NO_HZ facility uses an hrtimer to wake up a CPU when it is allowed to go into dyntick-idle mode, which is almost always cancelled soon after. This is not what hrtimers are good at, so this commit switches to the timer wheel. Reported-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| | * | rcu: Add RCU_FAST_NO_HZ tracing for idle exitPaul E. McKenney2012-04-242-0/+2
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | Traces of rcu_prep_idle events can be confusing because rcu_cleanup_after_idle() does no tracing. This commit therefore adds this tracing. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* | | Merge branch 'core-locking-for-linus' of ↵Linus Torvalds2012-05-214-84/+71
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core locking updates from Ingo Molnar: "This update: - extends and simplifies x86 NMI callback handling code to enhance and fix the HP hw-watchdog driver - simplifies the x86 NMI callback handling code to fix a kmemcheck bug. - enhances the hung-task debugger" * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/nmi: Fix the type of the nmiaction.flags field x86/nmi: Fix page faults by nmiaction if kmemcheck is enabled x86/nmi: Add new NMI queues to deal with IO_CHK and SERR watchdog, hpwdt: Remove priority option for NMI callback hung task debugging: Inject NMI when hung and going to panic
| * | | x86/nmi: Fix the type of the nmiaction.flags fieldBetty Dall2012-05-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes the type of the struct nmiaction flags field to unsigned long from unsigned int. All the usages of the flags field are unsigned long already. There is only one flag used currently, NMI_FLAG_FIRST, but having the wrong size could cause a truncation bug in the future on 64 bit architectures. Signed-off-by: Betty Dall <betty.dall@hp.com> Acked-by: Don Zickus <dzickus@redhat.com> Link: http://lkml.kernel.org/r/1335559255-13454-1-git-send-email-betty.dall@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/nmi: Fix page faults by nmiaction if kmemcheck is enabledLi Zhong2012-04-252-61/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch tries to fix the problem of page fault exception caused by accessing nmiaction structure in nmi if kmemcheck is enabled. If kmemcheck is enabled, the memory allocated through slab are in pages that are marked non-present, so that some checks could be done in the page fault handling code ( e.g. whether the memory is read before written to ). As nmiaction is allocated in this way, so it resides in a non-present page. Then there is a page fault while the nmi code accessing the nmiaction structure, which would then cause a warning by WARN_ON_ONCE(in_nmi()) in kmemcheck_fault(), called by do_page_fault(). This significantly simplifies the code as well, as the whole dynamic allocation dance goes away. v2: as Peter suggested, changed the nmiaction to use static storage. v3: as Peter suggested, use macro to shorten the codes. Also keep the original usage of register_nmi_handler, so users of this call doesn't need change. Tested-by: Seiji Aguchi <seiji.aguchi@hds.com> Fixes: https://lkml.org/lkml/2012/3/2/356 Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> [ simplified the wrappers ] Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: thomas.mingarelli@hp.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1333051877-15755-4-git-send-email-dzickus@redhat.com [ tidied the patch a bit ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | x86/nmi: Add new NMI queues to deal with IO_CHK and SERRDon Zickus2012-04-253-7/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In discussions with Thomas Mingarelli about hpwdt, he explained to me some issues they were some when using their virtual NMI button to test the hpwdt driver. It turns out the virtual NMI button used on HP's machines do no send unknown NMIs but instead send IO_CHK NMIs. The way the kernel code is written, the hpwdt driver can not register itself against that type of NMI and therefore can not successfully capture system information before panic'ing. To solve this I created two new NMI queues to allow driver to register against the IO_CHK and SERR NMIs. Or in the hpwdt all three (if you include unknown NMIs too). The change is straightforward and just mimics what the unknown NMI does. Reported-and-tested-by: Thomas Mingarelli <thomas.mingarelli@hp.com> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1333051877-15755-3-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | watchdog, hpwdt: Remove priority option for NMI callbackDon Zickus2012-04-251-15/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The NMI_UNKNOWN bucket only allows for one function to register to it. The reason for that is because only functions which can not determine if the NMI belongs to them or not should register and would like to assume/swallow any NMI they see. As a result it doesn't make sense to let more than one function like this register. In fact, letting a second function fail allows us to know that more than one function is going to swallow NMIs on the current system. This is better than silently being ignored. Therefore hpwdt's priority mechanism doesn't make sense any more. They will be always first on the NMI_UNKNOWN queue, if they register. Removing this parameter cleans up the code and simplifies things for the next patch which changes how nmis are registered. Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Thomas Mingarelli <thomas.mingarelli@hp.com> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1333051877-15755-2-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | hung task debugging: Inject NMI when hung and going to panicSasha Levin2012-04-251-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Send an NMI to all CPUs when a hung task is detected and the hung task code is configured to panic. This gives us a fairly uptodate snapshot of all CPUs in the system. This lets us get stack trace of all CPUs which makes life easier trying to debug a deadlock, and the NMI doesn't change anything since the next step is a kernel panic. Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1331848040-1676-1-git-send-email-levinsasha928@gmail.com [ extended the changelog a bit ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'core-iommu-for-linus' of ↵Linus Torvalds2012-05-2112-451/+731
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull iommu core changes from Ingo Molnar: "The IOMMU changes in this cycle are mostly about factoring out Intel-VT-d specific IRQ remapping details and introducing struct irq_remap_ops, in preparation for AMD specific hardware." * 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: iommu: Fix off by one in dmar_get_fault_reason() irq_remap: Fix the 'sub_handle' uninitialized warning irq_remap: Fix UP build failure irq_remap: Fix compiler warning with CONFIG_IRQ_REMAP=y iommu: rename intr_remapping.[ch] to irq_remapping.[ch] iommu: rename intr_remapping references to irq_remapping x86, iommu/vt-d: Clean up interfaces for interrupt remapping iommu/vt-d: Convert MSI remapping setup to remap_ops iommu/vt-d: Convert free_irte into a remap_ops callback iommu/vt-d: Convert IR set_affinity function to remap_ops iommu/vt-d: Convert IR ioapic-setup to use remap_ops iommu/vt-d: Convert missing apic.c intr-remapping call to remap_ops iommu/vt-d: Make intr-remapping initialization generic iommu: Rename intr_remapping files to intel_intr_remapping
| * | | | iommu: Fix off by one in dmar_get_fault_reason()Dan Carpenter2012-05-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fault_reason - 0x20 == ARRAY_SIZE(irq_remap_fault_reasons) is one past the end of the array. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Joerg Roedel <joerg.roedel@amd.com> Cc: Youquan Song <youquan.song@intel.com> Cc: walter harms <wharms@bfs.de> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: <stable@kernel.org> Link: http://lkml.kernel.org/r/20120513170938.GA4280@elgon.mountain Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | irq_remap: Fix the 'sub_handle' uninitialized warningSuresh Siddha2012-05-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix this uninitialized variable warning: drivers/iommu/intel_irq_remapping.c:986:12: warning: ‘sub_handle’ may be used uninitialized in this function [-Wuninitialized] GCC is wrong, help it out. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: joro@8bytes.org Cc: iommu@lists.linux-foundation.org Cc: Joerg Roedel <joerg.roedel@amd.com> Link: http://lkml.kernel.org/r/1336460934-23592-3-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | irq_remap: Fix UP build failureSuresh Siddha2012-05-083-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the below UP build failure with CONFIG_IRQ_REMAP enabled. drivers/iommu/intel_irq_remapping.c:955:19: error: ‘struct irq_data’ has no member named ‘affinity’ Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: joro@8bytes.org Cc: iommu@lists.linux-foundation.org Cc: Joerg Roedel <joerg.roedel@amd.com> Link: http://lkml.kernel.org/r/1336460934-23592-2-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | irq_remap: Fix compiler warning with CONFIG_IRQ_REMAP=ySuresh Siddha2012-05-081-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the below compiler warning: arch/x86/include/asm/irq_remapping.h:72:19: warning: ‘struct IO_APIC_route_entry’ declared inside parameter list [enabled by default] Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: joro@8bytes.org Cc: iommu@lists.linux-foundation.org Cc: Joerg Roedel <joerg.roedel@amd.com> Link: http://lkml.kernel.org/r/1336460934-23592-1-git-send-email-suresh.b.siddha@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | Merge tag 'intr-remapping-ops-for-ingo' of ↵Ingo Molnar2012-05-0712-450/+724
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu into core/iommu - This patchset introduces a generic ops-interface for accessing interrupt remapping hardware on x86. It factors out the VT-d specific code from io_apic.c and moves it to drivers/iommu. These changes will be used to add support for AMD interrupt remapping hardware. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | | iommu: rename intr_remapping.[ch] to irq_remapping.[ch]Suresh Siddha2012-05-0710-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the file names consistent with the naming conventions of irq subsystem. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Joerg Roedel <joerg.roedel@amd.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
| | * | | | iommu: rename intr_remapping references to irq_remappingSuresh Siddha2012-05-079-145/+148
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the code consistent with the naming conventions of irq subsystem. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Joerg Roedel <joerg.roedel@amd.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
| | * | | | x86, iommu/vt-d: Clean up interfaces for interrupt remappingJoerg Roedel2012-05-074-92/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the Intel specific interfaces from dmar.h and remove asm/irq_remapping.h which is only used for io_apic.c anyway. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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