diff options
Diffstat (limited to 'Documentation')
9 files changed, 87 insertions, 32 deletions
diff --git a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst index 93d899d53258..414f8a2012d6 100644 --- a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst +++ b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst @@ -181,7 +181,7 @@ operations is carried out at several levels: of this wait (or series of waits, as the case may be) is to permit a concurrent CPU-hotplug operation to complete. #. In the case of RCU-sched, one of the last acts of an outgoing CPU is - to invoke ``rcu_report_dead()``, which reports a quiescent state for + to invoke ``rcutree_report_cpu_dead()``, which reports a quiescent state for that CPU. However, this is likely paranoia-induced redundancy. +-----------------------------------------------------------------------+ diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-registry.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-registry.svg index 7ac6f9269806..63eff867175a 100644 --- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-registry.svg +++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-registry.svg @@ -566,15 +566,6 @@ style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_migrate_callbacks()</text> <text xml:space="preserve" - x="8335.4873" - y="5357.1006" - font-style="normal" - font-weight="bold" - font-size="192" - id="text202-7-9-6-0" - style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_migrate_callbacks()</text> - <text - xml:space="preserve" x="8768.4678" y="6224.9038" font-style="normal" diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg index 7ddc094d7f28..d82a77d03d8c 100644 --- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg +++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg @@ -1135,7 +1135,7 @@ font-weight="bold" font-size="192" id="text202-7-5-3-27-6-5" - style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_report_dead()</text> + style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_report_cpu_dead()</text> <text xml:space="preserve" x="3745.7725" @@ -1256,7 +1256,7 @@ font-style="normal" y="3679.27" x="-3804.9949" - xml:space="preserve">rcu_cpu_starting()</text> + xml:space="preserve">rcutree_report_cpu_starting()</text> <g style="fill:none;stroke-width:0.025in" id="g3107-7-5-0" diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg index 069f6f8371c2..53e0dc2a2c79 100644 --- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg +++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg @@ -1448,15 +1448,6 @@ style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_migrate_callbacks()</text> <text xml:space="preserve" - x="8335.4873" - y="5357.1006" - font-style="normal" - font-weight="bold" - font-size="192" - id="text202-7-9-6-0" - style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_migrate_callbacks()</text> - <text - xml:space="preserve" x="8768.4678" y="6224.9038" font-style="normal" @@ -3274,7 +3265,7 @@ font-weight="bold" font-size="192" id="text202-7-5-3-27-6-5" - style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_report_dead()</text> + style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_report_cpu_dead()</text> <text xml:space="preserve" x="3745.7725" @@ -3395,7 +3386,7 @@ font-style="normal" y="3679.27" x="-3804.9949" - xml:space="preserve">rcu_cpu_starting()</text> + xml:space="preserve">rcutree_report_cpu_starting()</text> <g style="fill:none;stroke-width:0.025in" id="g3107-7-5-0" diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-hotplug.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-hotplug.svg index 2c9310ba29ba..4fa7506082bf 100644 --- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-hotplug.svg +++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-hotplug.svg @@ -607,7 +607,7 @@ font-weight="bold" font-size="192" id="text202-7-5-3-27-6" - style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_report_dead()</text> + style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_report_cpu_dead()</text> <text xml:space="preserve" x="3745.7725" @@ -728,7 +728,7 @@ font-style="normal" y="3679.27" x="-3804.9949" - xml:space="preserve">rcu_cpu_starting()</text> + xml:space="preserve">rcutree_report_cpu_starting()</text> <g style="fill:none;stroke-width:0.025in" id="g3107-7-5-0" diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst index f3b605285a87..cccafdaa1f84 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.rst +++ b/Documentation/RCU/Design/Requirements/Requirements.rst @@ -1955,12 +1955,12 @@ if offline CPUs block an RCU grace period for too long. An offline CPU's quiescent state will be reported either: -1. As the CPU goes offline using RCU's hotplug notifier (rcu_report_dead()). +1. As the CPU goes offline using RCU's hotplug notifier (rcutree_report_cpu_dead()). 2. When grace period initialization (rcu_gp_init()) detects a race either with CPU offlining or with a task unblocking on a leaf ``rcu_node`` structure whose CPUs are all offline. -The CPU-online path (rcu_cpu_starting()) should never need to report +The CPU-online path (rcutree_report_cpu_starting()) should never need to report a quiescent state for an offline CPU. However, as a debugging measure, it does emit a warning if a quiescent state was not already reported for that CPU. diff --git a/Documentation/RCU/listRCU.rst b/Documentation/RCU/listRCU.rst index bdc4bcc5289f..ed5c9d8c9afe 100644 --- a/Documentation/RCU/listRCU.rst +++ b/Documentation/RCU/listRCU.rst @@ -8,6 +8,15 @@ One of the most common uses of RCU is protecting read-mostly linked lists that all of the required memory ordering is provided by the list macros. This document describes several list-based RCU use cases. +When iterating a list while holding the rcu_read_lock(), writers may +modify the list. The reader is guaranteed to see all of the elements +which were added to the list before they acquired the rcu_read_lock() +and are still on the list when they drop the rcu_read_unlock(). +Elements which are added to, or removed from the list may or may not +be seen. If the writer calls list_replace_rcu(), the reader may see +either the old element or the new element; they will not see both, +nor will they see neither. + Example 1: Read-mostly list: Deferred Destruction ------------------------------------------------- diff --git a/Documentation/RCU/whatisRCU.rst b/Documentation/RCU/whatisRCU.rst index e488c8e557a9..60ce02475142 100644 --- a/Documentation/RCU/whatisRCU.rst +++ b/Documentation/RCU/whatisRCU.rst @@ -59,8 +59,8 @@ experiment with should focus on Section 2. People who prefer to start with example uses should focus on Sections 3 and 4. People who need to understand the RCU implementation should focus on Section 5, then dive into the kernel source code. People who reason best by analogy should -focus on Section 6. Section 7 serves as an index to the docbook API -documentation, and Section 8 is the traditional answer key. +focus on Section 6 and 7. Section 8 serves as an index to the docbook +API documentation, and Section 9 is the traditional answer key. So, start with the section that makes the most sense to you and your preferred method of learning. If you need to know everything about diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 582f7a395153..dca212b6adfb 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2919,6 +2919,38 @@ to extract confidential information from the kernel are also disabled. + locktorture.acq_writer_lim= [KNL] + Set the time limit in jiffies for a lock + acquisition. Acquisitions exceeding this limit + will result in a splat once they do complete. + + locktorture.bind_readers= [KNL] + Specify the list of CPUs to which the readers are + to be bound. + + locktorture.bind_writers= [KNL] + Specify the list of CPUs to which the writers are + to be bound. + + locktorture.call_rcu_chains= [KNL] + Specify the number of self-propagating call_rcu() + chains to set up. These are used to ensure that + there is a high probability of an RCU grace period + in progress at any given time. Defaults to 0, + which disables these call_rcu() chains. + + locktorture.long_hold= [KNL] + Specify the duration in milliseconds for the + occasional long-duration lock hold time. Defaults + to 100 milliseconds. Select 0 to disable. + + locktorture.nested_locks= [KNL] + Specify the maximum lock nesting depth that + locktorture is to exercise, up to a limit of 8 + (MAX_NESTED_LOCKS). Specify zero to disable. + Note that this parameter is ineffective on types + of locks that do not support nested acquisition. + locktorture.nreaders_stress= [KNL] Set the number of locking read-acquisition kthreads. Defaults to being automatically set based on the @@ -2934,6 +2966,25 @@ Set time (s) between CPU-hotplug operations, or zero to disable CPU-hotplug testing. + locktorture.rt_boost= [KNL] + Do periodic testing of real-time lock priority + boosting. Select 0 to disable, 1 to boost + only rt_mutex, and 2 to boost unconditionally. + Defaults to 2, which might seem to be an + odd choice, but which should be harmless for + non-real-time spinlocks, due to their disabling + of preemption. Note that non-realtime mutexes + disable boosting. + + locktorture.rt_boost_factor= [KNL] + Number that determines how often and for how + long priority boosting is exercised. This is + scaled down by the number of writers, so that the + number of boosts per unit time remains roughly + constant as the number of writers increases. + On the other hand, the duration of each boost + increases with the number of writers. + locktorture.shuffle_interval= [KNL] Set task-shuffle interval (jiffies). Shuffling tasks allows some CPUs to go into dyntick-idle @@ -2956,13 +3007,13 @@ locktorture.torture_type= [KNL] Specify the locking implementation to test. + locktorture.verbose= [KNL] + Enable additional printk() statements. + locktorture.writer_fifo= [KNL] Run the write-side locktorture kthreads at sched_set_fifo() real-time priority. - locktorture.verbose= [KNL] - Enable additional printk() statements. - logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver Format: <irq> @@ -4775,6 +4826,13 @@ Set maximum number of finished RCU callbacks to process in one batch. + rcutree.do_rcu_barrier= [KNL] + Request a call to rcu_barrier(). This is + throttled so that userspace tests can safely + hammer on the sysfs variable if they so choose. + If triggered before the RCU grace-period machinery + is fully active, this will error out with EAGAIN. + rcutree.dump_tree= [KNL] Dump the structure of the rcu_node combining tree out at early boot. This is used for diagnostic @@ -5428,6 +5486,12 @@ test until boot completes in order to avoid interference. + refscale.lookup_instances= [KNL] + Number of data elements to use for the forms of + SLAB_TYPESAFE_BY_RCU testing. A negative number + is negated and multiplied by nr_cpu_ids, while + zero specifies nr_cpu_ids. + refscale.loops= [KNL] Set the number of loops over the synchronization primitive under test. Increasing this number |
