diff options
Diffstat (limited to 'kernel/rcu/srcutree.c')
| -rw-r--r-- | kernel/rcu/srcutree.c | 45 |
1 files changed, 36 insertions, 9 deletions
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index b9dec26245e0..862008c147b0 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -330,18 +330,13 @@ static void srcu_transition_to_big(struct srcu_struct *ssp) } /* - * Acquire the specified srcu_struct structure's ->lock, but check for - * excessive contention, which results in initiation of a transition - * to SRCU_SIZE_BIG. But only if the srcutree.convert_to_big module - * parameter permits this. + * Check to see if the just-encountered contention event justifies + * a transition to SRCU_SIZE_BIG. */ -static void spin_lock_irqsave_ssp_contention(struct srcu_struct *ssp, unsigned long *flags) +static void spin_lock_irqsave_check_contention(struct srcu_struct *ssp) { unsigned long j; - if (spin_trylock_irqsave_rcu_node(ssp, *flags)) - return; - spin_lock_irqsave_rcu_node(ssp, *flags); if (!SRCU_SIZING_IS_CONTEND() || ssp->srcu_size_state) return; j = jiffies; @@ -355,6 +350,38 @@ static void spin_lock_irqsave_ssp_contention(struct srcu_struct *ssp, unsigned l } /* + * Acquire the specified srcu_data structure's ->lock, but check for + * excessive contention, which results in initiation of a transition + * to SRCU_SIZE_BIG. But only if the srcutree.convert_to_big module + * parameter permits this. + */ +static void spin_lock_irqsave_sdp_contention(struct srcu_data *sdp, unsigned long *flags) +{ + struct srcu_struct *ssp = sdp->ssp; + + if (spin_trylock_irqsave_rcu_node(sdp, *flags)) + return; + spin_lock_irqsave_rcu_node(ssp, *flags); + spin_lock_irqsave_check_contention(ssp); + spin_unlock_irqrestore_rcu_node(ssp, *flags); + spin_lock_irqsave_rcu_node(sdp, *flags); +} + +/* + * Acquire the specified srcu_struct structure's ->lock, but check for + * excessive contention, which results in initiation of a transition + * to SRCU_SIZE_BIG. But only if the srcutree.convert_to_big module + * parameter permits this. + */ +static void spin_lock_irqsave_ssp_contention(struct srcu_struct *ssp, unsigned long *flags) +{ + if (spin_trylock_irqsave_rcu_node(ssp, *flags)) + return; + spin_lock_irqsave_rcu_node(ssp, *flags); + spin_lock_irqsave_check_contention(ssp); +} + +/* * First-use initialization of statically allocated srcu_struct * structure. Wiring up the combining tree is more than can be * done with compile-time initialization, so this check is added @@ -1010,7 +1037,7 @@ static unsigned long srcu_gp_start_if_needed(struct srcu_struct *ssp, sdp = per_cpu_ptr(ssp->sda, 0); else sdp = raw_cpu_ptr(ssp->sda); - spin_lock_irqsave_rcu_node(sdp, flags); + spin_lock_irqsave_sdp_contention(sdp, &flags); if (rhp) rcu_segcblist_enqueue(&sdp->srcu_cblist, rhp); rcu_segcblist_advance(&sdp->srcu_cblist, |