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 fcbb736d55fe..203f4a9d9efe 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt | |||
@@ -2599,7 +2599,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
2599 | ramdisk_size= [RAM] Sizes of RAM disks in kilobytes | 2599 | ramdisk_size= [RAM] Sizes of RAM disks in kilobytes |
2600 | See Documentation/blockdev/ramdisk.txt. | 2600 | See Documentation/blockdev/ramdisk.txt. |
2601 | 2601 | ||
2602 | rcu_nocbs= [KNL,BOOT] | 2602 | rcu_nocbs= [KNL] |
2603 | In kernels built with CONFIG_RCU_NOCB_CPU=y, set | 2603 | In kernels built with CONFIG_RCU_NOCB_CPU=y, set |
2604 | the specified list of CPUs to be no-callback CPUs. | 2604 | the specified list of CPUs to be no-callback CPUs. |
2605 | Invocation of these CPUs' RCU callbacks will | 2605 | Invocation of these CPUs' RCU callbacks will |
@@ -2612,7 +2612,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
2612 | real-time workloads. It can also improve energy | 2612 | real-time workloads. It can also improve energy |
2613 | efficiency for asymmetric multiprocessors. | 2613 | efficiency for asymmetric multiprocessors. |
2614 | 2614 | ||
2615 | rcu_nocb_poll [KNL,BOOT] | 2615 | rcu_nocb_poll [KNL] |
2616 | Rather than requiring that offloaded CPUs | 2616 | Rather than requiring that offloaded CPUs |
2617 | (specified by rcu_nocbs= above) explicitly | 2617 | (specified by rcu_nocbs= above) explicitly |
2618 | awaken the corresponding "rcuoN" kthreads, | 2618 | awaken the corresponding "rcuoN" kthreads, |
@@ -2623,126 +2623,145 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
2623 | energy efficiency by requiring that the kthreads | 2623 | energy efficiency by requiring that the kthreads |
2624 | periodically wake up to do the polling. | 2624 | periodically wake up to do the polling. |
2625 | 2625 | ||
2626 | rcutree.blimit= [KNL,BOOT] | 2626 | rcutree.blimit= [KNL] |
2627 | Set maximum number of finished RCU callbacks to process | 2627 | Set maximum number of finished RCU callbacks to process |
2628 | in one batch. | 2628 | in one batch. |
2629 | 2629 | ||
2630 | rcutree.fanout_leaf= [KNL,BOOT] | 2630 | rcutree.rcu_fanout_leaf= [KNL] |
2631 | Increase the number of CPUs assigned to each | 2631 | Increase the number of CPUs assigned to each |
2632 | leaf rcu_node structure. Useful for very large | 2632 | leaf rcu_node structure. Useful for very large |
2633 | systems. | 2633 | systems. |
2634 | 2634 | ||
2635 | rcutree.jiffies_till_first_fqs= [KNL,BOOT] | 2635 | rcutree.jiffies_till_first_fqs= [KNL] |
2636 | Set delay from grace-period initialization to | 2636 | Set delay from grace-period initialization to |
2637 | first attempt to force quiescent states. | 2637 | first attempt to force quiescent states. |
2638 | Units are jiffies, minimum value is zero, | 2638 | Units are jiffies, minimum value is zero, |
2639 | and maximum value is HZ. | 2639 | and maximum value is HZ. |
2640 | 2640 | ||
2641 | rcutree.jiffies_till_next_fqs= [KNL,BOOT] | 2641 | rcutree.jiffies_till_next_fqs= [KNL] |
2642 | Set delay between subsequent attempts to force | 2642 | Set delay between subsequent attempts to force |
2643 | quiescent states. Units are jiffies, minimum | 2643 | quiescent states. Units are jiffies, minimum |
2644 | value is one, and maximum value is HZ. | 2644 | value is one, and maximum value is HZ. |
2645 | 2645 | ||
2646 | rcutree.qhimark= [KNL,BOOT] | 2646 | rcutree.qhimark= [KNL] |
2647 | Set threshold of queued | 2647 | Set threshold of queued |
2648 | RCU callbacks over which batch limiting is disabled. | 2648 | RCU callbacks over which batch limiting is disabled. |
2649 | 2649 | ||
2650 | rcutree.qlowmark= [KNL,BOOT] | 2650 | rcutree.qlowmark= [KNL] |
2651 | Set threshold of queued RCU callbacks below which | 2651 | Set threshold of queued RCU callbacks below which |
2652 | batch limiting is re-enabled. | 2652 | batch limiting is re-enabled. |
2653 | 2653 | ||
2654 | rcutree.rcu_cpu_stall_suppress= [KNL,BOOT] | 2654 | rcutree.rcu_idle_gp_delay= [KNL] |
2655 | Suppress RCU CPU stall warning messages. | ||
2656 | |||
2657 | rcutree.rcu_cpu_stall_timeout= [KNL,BOOT] | ||
2658 | Set timeout for RCU CPU stall warning messages. | ||
2659 | |||
2660 | rcutree.rcu_idle_gp_delay= [KNL,BOOT] | ||
2661 | Set wakeup interval for idle CPUs that have | 2655 | Set wakeup interval for idle CPUs that have |
2662 | RCU callbacks (RCU_FAST_NO_HZ=y). | 2656 | RCU callbacks (RCU_FAST_NO_HZ=y). |
2663 | 2657 | ||
2664 | rcutree.rcu_idle_lazy_gp_delay= [KNL,BOOT] | 2658 | rcutree.rcu_idle_lazy_gp_delay= [KNL] |
2665 | Set wakeup interval for idle CPUs that have | 2659 | Set wakeup interval for idle CPUs that have |
2666 | only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y). | 2660 | only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y). |
2667 | Lazy RCU callbacks are those which RCU can | 2661 | Lazy RCU callbacks are those which RCU can |
2668 | prove do nothing more than free memory. | 2662 | prove do nothing more than free memory. |
2669 | 2663 | ||
2670 | rcutorture.fqs_duration= [KNL,BOOT] | 2664 | rcutorture.fqs_duration= [KNL] |
2671 | Set duration of force_quiescent_state bursts. | 2665 | Set duration of force_quiescent_state bursts. |
2672 | 2666 | ||
2673 | rcutorture.fqs_holdoff= [KNL,BOOT] | 2667 | rcutorture.fqs_holdoff= [KNL] |
2674 | Set holdoff time within force_quiescent_state bursts. | 2668 | Set holdoff time within force_quiescent_state bursts. |
2675 | 2669 | ||
2676 | rcutorture.fqs_stutter= [KNL,BOOT] | 2670 | rcutorture.fqs_stutter= [KNL] |
2677 | Set wait time between force_quiescent_state bursts. | 2671 | Set wait time between force_quiescent_state bursts. |
2678 | 2672 | ||
2679 | rcutorture.irqreader= [KNL,BOOT] | 2673 | rcutorture.gp_exp= [KNL] |
2680 | Test RCU readers from irq handlers. | 2674 | Use expedited update-side primitives. |
2675 | |||
2676 | rcutorture.gp_normal= [KNL] | ||
2677 | Use normal (non-expedited) update-side primitives. | ||
2678 | If both gp_exp and gp_normal are set, do both. | ||
2679 | If neither gp_exp nor gp_normal are set, still | ||
2680 | do both. | ||
2681 | 2681 | ||
2682 | rcutorture.n_barrier_cbs= [KNL,BOOT] | 2682 | rcutorture.n_barrier_cbs= [KNL] |
2683 | Set callbacks/threads for rcu_barrier() testing. | 2683 | Set callbacks/threads for rcu_barrier() testing. |
2684 | 2684 | ||
2685 | rcutorture.nfakewriters= [KNL,BOOT] | 2685 | rcutorture.nfakewriters= [KNL] |
2686 | Set number of concurrent RCU writers. These just | 2686 | Set number of concurrent RCU writers. These just |
2687 | stress RCU, they don't participate in the actual | 2687 | stress RCU, they don't participate in the actual |
2688 | test, hence the "fake". | 2688 | test, hence the "fake". |
2689 | 2689 | ||
2690 | rcutorture.nreaders= [KNL,BOOT] | 2690 | rcutorture.nreaders= [KNL] |
2691 | Set number of RCU readers. | 2691 | Set number of RCU readers. |
2692 | 2692 | ||
2693 | rcutorture.onoff_holdoff= [KNL,BOOT] | 2693 | rcutorture.object_debug= [KNL] |
2694 | Enable debug-object double-call_rcu() testing. | ||
2695 | |||
2696 | rcutorture.onoff_holdoff= [KNL] | ||
2694 | Set time (s) after boot for CPU-hotplug testing. | 2697 | Set time (s) after boot for CPU-hotplug testing. |
2695 | 2698 | ||
2696 | rcutorture.onoff_interval= [KNL,BOOT] | 2699 | rcutorture.onoff_interval= [KNL] |
2697 | Set time (s) between CPU-hotplug operations, or | 2700 | Set time (s) between CPU-hotplug operations, or |
2698 | zero to disable CPU-hotplug testing. | 2701 | zero to disable CPU-hotplug testing. |
2699 | 2702 | ||
2700 | rcutorture.shuffle_interval= [KNL,BOOT] | 2703 | rcutorture.rcutorture_runnable= [BOOT] |
2704 | Start rcutorture running at boot time. | ||
2705 | |||
2706 | rcutorture.shuffle_interval= [KNL] | ||
2701 | Set task-shuffle interval (s). Shuffling tasks | 2707 | Set task-shuffle interval (s). Shuffling tasks |
2702 | allows some CPUs to go into dyntick-idle mode | 2708 | allows some CPUs to go into dyntick-idle mode |
2703 | during the rcutorture test. | 2709 | during the rcutorture test. |
2704 | 2710 | ||
2705 | rcutorture.shutdown_secs= [KNL,BOOT] | 2711 | rcutorture.shutdown_secs= [KNL] |
2706 | Set time (s) after boot system shutdown. This | 2712 | Set time (s) after boot system shutdown. This |
2707 | is useful for hands-off automated testing. | 2713 | is useful for hands-off automated testing. |
2708 | 2714 | ||
2709 | rcutorture.stall_cpu= [KNL,BOOT] | 2715 | rcutorture.stall_cpu= [KNL] |
2710 | Duration of CPU stall (s) to test RCU CPU stall | 2716 | Duration of CPU stall (s) to test RCU CPU stall |
2711 | warnings, zero to disable. | 2717 | warnings, zero to disable. |
2712 | 2718 | ||
2713 | rcutorture.stall_cpu_holdoff= [KNL,BOOT] | 2719 | rcutorture.stall_cpu_holdoff= [KNL] |
2714 | Time to wait (s) after boot before inducing stall. | 2720 | Time to wait (s) after boot before inducing stall. |
2715 | 2721 | ||
2716 | rcutorture.stat_interval= [KNL,BOOT] | 2722 | rcutorture.stat_interval= [KNL] |
2717 | Time (s) between statistics printk()s. | 2723 | Time (s) between statistics printk()s. |
2718 | 2724 | ||
2719 | rcutorture.stutter= [KNL,BOOT] | 2725 | rcutorture.stutter= [KNL] |
2720 | Time (s) to stutter testing, for example, specifying | 2726 | Time (s) to stutter testing, for example, specifying |
2721 | five seconds causes the test to run for five seconds, | 2727 | five seconds causes the test to run for five seconds, |
2722 | wait for five seconds, and so on. This tests RCU's | 2728 | wait for five seconds, and so on. This tests RCU's |
2723 | ability to transition abruptly to and from idle. | 2729 | ability to transition abruptly to and from idle. |
2724 | 2730 | ||
2725 | rcutorture.test_boost= [KNL,BOOT] | 2731 | rcutorture.test_boost= [KNL] |
2726 | Test RCU priority boosting? 0=no, 1=maybe, 2=yes. | 2732 | Test RCU priority boosting? 0=no, 1=maybe, 2=yes. |
2727 | "Maybe" means test if the RCU implementation | 2733 | "Maybe" means test if the RCU implementation |
2728 | under test support RCU priority boosting. | 2734 | under test support RCU priority boosting. |
2729 | 2735 | ||
2730 | rcutorture.test_boost_duration= [KNL,BOOT] | 2736 | rcutorture.test_boost_duration= [KNL] |
2731 | Duration (s) of each individual boost test. | 2737 | Duration (s) of each individual boost test. |
2732 | 2738 | ||
2733 | rcutorture.test_boost_interval= [KNL,BOOT] | 2739 | rcutorture.test_boost_interval= [KNL] |
2734 | Interval (s) between each boost test. | 2740 | Interval (s) between each boost test. |
2735 | 2741 | ||
2736 | rcutorture.test_no_idle_hz= [KNL,BOOT] | 2742 | rcutorture.test_no_idle_hz= [KNL] |
2737 | Test RCU's dyntick-idle handling. See also the | 2743 | Test RCU's dyntick-idle handling. See also the |
2738 | rcutorture.shuffle_interval parameter. | 2744 | rcutorture.shuffle_interval parameter. |
2739 | 2745 | ||
2740 | rcutorture.torture_type= [KNL,BOOT] | 2746 | rcutorture.torture_type= [KNL] |
2741 | Specify the RCU implementation to test. | 2747 | Specify the RCU implementation to test. |
2742 | 2748 | ||
2743 | rcutorture.verbose= [KNL,BOOT] | 2749 | rcutorture.verbose= [KNL] |
2744 | Enable additional printk() statements. | 2750 | Enable additional printk() statements. |
2745 | 2751 | ||
2752 | rcupdate.rcu_expedited= [KNL] | ||
2753 | Use expedited grace-period primitives, for | ||
2754 | example, synchronize_rcu_expedited() instead | ||
2755 | of synchronize_rcu(). This reduces latency, | ||
2756 | but can increase CPU utilization, degrade | ||
2757 | real-time latency, and degrade energy efficiency. | ||
2758 | |||
2759 | rcupdate.rcu_cpu_stall_suppress= [KNL] | ||
2760 | Suppress RCU CPU stall warning messages. | ||
2761 | |||
2762 | rcupdate.rcu_cpu_stall_timeout= [KNL] | ||
2763 | Set timeout for RCU CPU stall warning messages. | ||
2764 | |||
2746 | rdinit= [KNL] | 2765 | rdinit= [KNL] |
2747 | Format: <full_path> | 2766 | Format: <full_path> |
2748 | Run specified binary instead of /init from the ramdisk, | 2767 | Run specified binary instead of /init from the ramdisk, |