diff options
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 95 |
1 files changed, 57 insertions, 38 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 1a036cd972fb..c3dc13e90a40 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2595,7 +2595,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ramdisk_size= [RAM] Sizes of RAM disks in kilobytes See Documentation/blockdev/ramdisk.txt. - rcu_nocbs= [KNL,BOOT] + rcu_nocbs= [KNL] In kernels built with CONFIG_RCU_NOCB_CPU=y, set the specified list of CPUs to be no-callback CPUs. Invocation of these CPUs' RCU callbacks will @@ -2608,7 +2608,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. real-time workloads. It can also improve energy efficiency for asymmetric multiprocessors. - rcu_nocb_poll [KNL,BOOT] + rcu_nocb_poll [KNL] Rather than requiring that offloaded CPUs (specified by rcu_nocbs= above) explicitly awaken the corresponding "rcuoN" kthreads, @@ -2619,126 +2619,145 @@ bytes respectively. Such letter suffixes can also be entirely omitted. energy efficiency by requiring that the kthreads periodically wake up to do the polling. - rcutree.blimit= [KNL,BOOT] + rcutree.blimit= [KNL] Set maximum number of finished RCU callbacks to process in one batch. - rcutree.fanout_leaf= [KNL,BOOT] + rcutree.rcu_fanout_leaf= [KNL] Increase the number of CPUs assigned to each leaf rcu_node structure. Useful for very large systems. - rcutree.jiffies_till_first_fqs= [KNL,BOOT] + rcutree.jiffies_till_first_fqs= [KNL] Set delay from grace-period initialization to first attempt to force quiescent states. Units are jiffies, minimum value is zero, and maximum value is HZ. - rcutree.jiffies_till_next_fqs= [KNL,BOOT] + rcutree.jiffies_till_next_fqs= [KNL] Set delay between subsequent attempts to force quiescent states. Units are jiffies, minimum value is one, and maximum value is HZ. - rcutree.qhimark= [KNL,BOOT] + rcutree.qhimark= [KNL] Set threshold of queued RCU callbacks over which batch limiting is disabled. - rcutree.qlowmark= [KNL,BOOT] + rcutree.qlowmark= [KNL] Set threshold of queued RCU callbacks below which batch limiting is re-enabled. - rcutree.rcu_cpu_stall_suppress= [KNL,BOOT] - Suppress RCU CPU stall warning messages. - - rcutree.rcu_cpu_stall_timeout= [KNL,BOOT] - Set timeout for RCU CPU stall warning messages. - - rcutree.rcu_idle_gp_delay= [KNL,BOOT] + rcutree.rcu_idle_gp_delay= [KNL] Set wakeup interval for idle CPUs that have RCU callbacks (RCU_FAST_NO_HZ=y). - rcutree.rcu_idle_lazy_gp_delay= [KNL,BOOT] + rcutree.rcu_idle_lazy_gp_delay= [KNL] Set wakeup interval for idle CPUs that have only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y). Lazy RCU callbacks are those which RCU can prove do nothing more than free memory. - rcutorture.fqs_duration= [KNL,BOOT] + rcutorture.fqs_duration= [KNL] Set duration of force_quiescent_state bursts. - rcutorture.fqs_holdoff= [KNL,BOOT] + rcutorture.fqs_holdoff= [KNL] Set holdoff time within force_quiescent_state bursts. - rcutorture.fqs_stutter= [KNL,BOOT] + rcutorture.fqs_stutter= [KNL] Set wait time between force_quiescent_state bursts. - rcutorture.irqreader= [KNL,BOOT] - Test RCU readers from irq handlers. + rcutorture.gp_exp= [KNL] + Use expedited update-side primitives. + + rcutorture.gp_normal= [KNL] + Use normal (non-expedited) update-side primitives. + If both gp_exp and gp_normal are set, do both. + If neither gp_exp nor gp_normal are set, still + do both. - rcutorture.n_barrier_cbs= [KNL,BOOT] + rcutorture.n_barrier_cbs= [KNL] Set callbacks/threads for rcu_barrier() testing. - rcutorture.nfakewriters= [KNL,BOOT] + rcutorture.nfakewriters= [KNL] Set number of concurrent RCU writers. These just stress RCU, they don't participate in the actual test, hence the "fake". - rcutorture.nreaders= [KNL,BOOT] + rcutorture.nreaders= [KNL] Set number of RCU readers. - rcutorture.onoff_holdoff= [KNL,BOOT] + rcutorture.object_debug= [KNL] + Enable debug-object double-call_rcu() testing. + + rcutorture.onoff_holdoff= [KNL] Set time (s) after boot for CPU-hotplug testing. - rcutorture.onoff_interval= [KNL,BOOT] + rcutorture.onoff_interval= [KNL] Set time (s) between CPU-hotplug operations, or zero to disable CPU-hotplug testing. - rcutorture.shuffle_interval= [KNL,BOOT] + rcutorture.rcutorture_runnable= [BOOT] + Start rcutorture running at boot time. + + rcutorture.shuffle_interval= [KNL] Set task-shuffle interval (s). Shuffling tasks allows some CPUs to go into dyntick-idle mode during the rcutorture test. - rcutorture.shutdown_secs= [KNL,BOOT] + rcutorture.shutdown_secs= [KNL] Set time (s) after boot system shutdown. This is useful for hands-off automated testing. - rcutorture.stall_cpu= [KNL,BOOT] + rcutorture.stall_cpu= [KNL] Duration of CPU stall (s) to test RCU CPU stall warnings, zero to disable. - rcutorture.stall_cpu_holdoff= [KNL,BOOT] + rcutorture.stall_cpu_holdoff= [KNL] Time to wait (s) after boot before inducing stall. - rcutorture.stat_interval= [KNL,BOOT] + rcutorture.stat_interval= [KNL] Time (s) between statistics printk()s. - rcutorture.stutter= [KNL,BOOT] + rcutorture.stutter= [KNL] Time (s) to stutter testing, for example, specifying five seconds causes the test to run for five seconds, wait for five seconds, and so on. This tests RCU's ability to transition abruptly to and from idle. - rcutorture.test_boost= [KNL,BOOT] + rcutorture.test_boost= [KNL] Test RCU priority boosting? 0=no, 1=maybe, 2=yes. "Maybe" means test if the RCU implementation under test support RCU priority boosting. - rcutorture.test_boost_duration= [KNL,BOOT] + rcutorture.test_boost_duration= [KNL] Duration (s) of each individual boost test. - rcutorture.test_boost_interval= [KNL,BOOT] + rcutorture.test_boost_interval= [KNL] Interval (s) between each boost test. - rcutorture.test_no_idle_hz= [KNL,BOOT] + rcutorture.test_no_idle_hz= [KNL] Test RCU's dyntick-idle handling. See also the rcutorture.shuffle_interval parameter. - rcutorture.torture_type= [KNL,BOOT] + rcutorture.torture_type= [KNL] Specify the RCU implementation to test. - rcutorture.verbose= [KNL,BOOT] + rcutorture.verbose= [KNL] Enable additional printk() statements. + rcupdate.rcu_expedited= [KNL] + Use expedited grace-period primitives, for + example, synchronize_rcu_expedited() instead + of synchronize_rcu(). This reduces latency, + but can increase CPU utilization, degrade + real-time latency, and degrade energy efficiency. + + rcupdate.rcu_cpu_stall_suppress= [KNL] + Suppress RCU CPU stall warning messages. + + rcupdate.rcu_cpu_stall_timeout= [KNL] + Set timeout for RCU CPU stall warning messages. + rdinit= [KNL] Format: <full_path> Run specified binary instead of /init from the ramdisk, |