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| author | Petr Mladek <pmladek@suse.com> | 2015-09-09 21:09:49 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-10-06 20:15:59 +0200 |
| commit | 77f81fe08ebd99d7e0eefde42ddac06a675bc4ad (patch) | |
| tree | 6d5d0c2faad078f738bf6c1d7e0d63504101e720 /kernel/rcu/tree.h | |
| parent | rcu: Move preemption disabling out of __srcu_read_lock() (diff) | |
| download | linux-77f81fe08ebd99d7e0eefde42ddac06a675bc4ad.tar.xz linux-77f81fe08ebd99d7e0eefde42ddac06a675bc4ad.zip | |
rcu: Finish folding ->fqs_state into ->gp_state
Commit commit 4cdfc175c25c89ee ("rcu: Move quiescent-state forcing
into kthread") started the process of folding the old ->fqs_state into
->gp_state, but did not complete it. This situation does not cause
any malfunction, but can result in extremely confusing trace output.
This commit completes this task of eliminating ->fqs_state in favor
of ->gp_state.
The old ->fqs_state was also used to decide when to collect dyntick-idle
snapshots. For this purpose, we add a boolean variable into the kthread,
which is set on the first call to rcu_gp_fqs() for a given grace period
and clear otherwise.
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcu/tree.h')
| -rw-r--r-- | kernel/rcu/tree.h | 14 |
1 files changed, 3 insertions, 11 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 0c33c82cec64..be6d1e8eeb79 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -412,13 +412,6 @@ struct rcu_data { struct rcu_state *rsp; }; -/* Values for fqs_state field in struct rcu_state. */ -#define RCU_GP_IDLE 0 /* No grace period in progress. */ -#define RCU_GP_INIT 1 /* Grace period being initialized. */ -#define RCU_SAVE_DYNTICK 2 /* Need to scan dyntick state. */ -#define RCU_FORCE_QS 3 /* Need to force quiescent state. */ -#define RCU_SIGNAL_INIT RCU_SAVE_DYNTICK - /* Values for nocb_defer_wakeup field in struct rcu_data. */ #define RCU_NOGP_WAKE_NOT 0 #define RCU_NOGP_WAKE 1 @@ -468,9 +461,8 @@ struct rcu_state { /* The following fields are guarded by the root rcu_node's lock. */ - u8 fqs_state ____cacheline_internodealigned_in_smp; - /* Force QS state. */ - u8 boost; /* Subject to priority boost. */ + u8 boost ____cacheline_internodealigned_in_smp; + /* Subject to priority boost. */ unsigned long gpnum; /* Current gp number. */ unsigned long completed; /* # of last completed gp. */ struct task_struct *gp_kthread; /* Task for grace periods. */ @@ -538,7 +530,7 @@ struct rcu_state { #define RCU_GP_FLAG_FQS 0x2 /* Need grace-period quiescent-state forcing. */ /* Values for rcu_state structure's gp_flags field. */ -#define RCU_GP_WAIT_INIT 0 /* Initial state. */ +#define RCU_GP_IDLE 0 /* Initial state and no GP in progress. */ #define RCU_GP_WAIT_GPS 1 /* Wait for grace-period start. */ #define RCU_GP_DONE_GPS 2 /* Wait done for grace-period start. */ #define RCU_GP_WAIT_FQS 3 /* Wait for force-quiescent-state time. */ |