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author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-06 11:36:10 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-06 11:36:10 +0300 |
commit | a769f30c7bd7cf917eea05a2b448f3588a87d767 (patch) | |
tree | 10a06089a9525926e23675528dd8190d05849143 /kernel/rcu/tree.c | |
parent | 307a082484eb0201ad123f39f95510a9da11985b (diff) | |
parent | d5adbfcd5f7bcc6fa58a41c5c5ada0e5c826ce2c (diff) | |
download | linux-a769f30c7bd7cf917eea05a2b448f3588a87d767.tar.xz |
Merge 4.10-rc7 into staging-next
This resolves the merge errors that were reported in linux-next and it
picks up the staging and IIO fixes that we need/want in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/rcu/tree.c')
-rw-r--r-- | kernel/rcu/tree.c | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 96c52e43f7ca..cb4e2056ccf3 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -127,13 +127,16 @@ int rcu_num_nodes __read_mostly = NUM_RCU_NODES; /* Total # rcu_nodes in use. */ int sysctl_panic_on_rcu_stall __read_mostly; /* - * The rcu_scheduler_active variable transitions from zero to one just - * before the first task is spawned. So when this variable is zero, RCU - * can assume that there is but one task, allowing RCU to (for example) + * The rcu_scheduler_active variable is initialized to the value + * RCU_SCHEDULER_INACTIVE and transitions RCU_SCHEDULER_INIT just before the + * first task is spawned. So when this variable is RCU_SCHEDULER_INACTIVE, + * RCU can assume that there is but one task, allowing RCU to (for example) * optimize synchronize_rcu() to a simple barrier(). When this variable - * is one, RCU must actually do all the hard work required to detect real - * grace periods. This variable is also used to suppress boot-time false - * positives from lockdep-RCU error checking. + * is RCU_SCHEDULER_INIT, RCU must actually do all the hard work required + * to detect real grace periods. This variable is also used to suppress + * boot-time false positives from lockdep-RCU error checking. Finally, it + * transitions from RCU_SCHEDULER_INIT to RCU_SCHEDULER_RUNNING after RCU + * is fully initialized, including all of its kthreads having been spawned. */ int rcu_scheduler_active __read_mostly; EXPORT_SYMBOL_GPL(rcu_scheduler_active); @@ -3980,18 +3983,22 @@ static int __init rcu_spawn_gp_kthread(void) early_initcall(rcu_spawn_gp_kthread); /* - * This function is invoked towards the end of the scheduler's initialization - * process. Before this is called, the idle task might contain - * RCU read-side critical sections (during which time, this idle - * task is booting the system). After this function is called, the - * idle tasks are prohibited from containing RCU read-side critical - * sections. This function also enables RCU lockdep checking. + * This function is invoked towards the end of the scheduler's + * initialization process. Before this is called, the idle task might + * contain synchronous grace-period primitives (during which time, this idle + * task is booting the system, and such primitives are no-ops). After this + * function is called, any synchronous grace-period primitives are run as + * expedited, with the requesting task driving the grace period forward. + * A later core_initcall() rcu_exp_runtime_mode() will switch to full + * runtime RCU functionality. */ void rcu_scheduler_starting(void) { WARN_ON(num_online_cpus() != 1); WARN_ON(nr_context_switches() > 0); - rcu_scheduler_active = 1; + rcu_test_sync_prims(); + rcu_scheduler_active = RCU_SCHEDULER_INIT; + rcu_test_sync_prims(); } /* |