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authorPaul E. McKenney <paulmck@kernel.org>2023-03-17 20:01:02 -0700
committerPaul E. McKenney <paulmck@kernel.org>2023-04-04 08:36:23 -0700
commit3b46679c623c2766f4c56fd3f9ce8edbb38c5d20 (patch)
tree4904c05df78ea85ed7c133e8ef16a60eaac41fb5 /kernel/rcu/srcutree.c
parent03200b5ca3b4d4edf634dc052bf3b8eb8dc8bbbc (diff)
srcu: Move heuristics fields from srcu_struct to srcu_usage
This commit moves the ->srcu_size_jiffies, ->srcu_n_lock_retries, and ->srcu_n_exp_nodelay fields from the srcu_struct structure to the srcu_usage structure to reduce the size of the former in order to improve cache locality. Suggested-by: Christoph Hellwig <hch@lst.de> Tested-by: Sachin Sant <sachinp@linux.ibm.com> Tested-by: "Zhang, Qiang1" <qiang1.zhang@intel.com> Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/srcutree.c')
-rw-r--r--kernel/rcu/srcutree.c18
1 files changed, 9 insertions, 9 deletions
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 340eb685cf64..291fb520bce0 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -348,11 +348,11 @@ static void spin_lock_irqsave_check_contention(struct srcu_struct *ssp)
if (!SRCU_SIZING_IS_CONTEND() || ssp->srcu_sup->srcu_size_state)
return;
j = jiffies;
- if (ssp->srcu_size_jiffies != j) {
- ssp->srcu_size_jiffies = j;
- ssp->srcu_n_lock_retries = 0;
+ if (ssp->srcu_sup->srcu_size_jiffies != j) {
+ ssp->srcu_sup->srcu_size_jiffies = j;
+ ssp->srcu_sup->srcu_n_lock_retries = 0;
}
- if (++ssp->srcu_n_lock_retries <= small_contention_lim)
+ if (++ssp->srcu_sup->srcu_n_lock_retries <= small_contention_lim)
return;
__srcu_transition_to_big(ssp);
}
@@ -624,8 +624,8 @@ static unsigned long srcu_get_delay(struct srcu_struct *ssp)
if (time_after(j, gpstart))
jbase += j - gpstart;
if (!jbase) {
- WRITE_ONCE(ssp->srcu_n_exp_nodelay, READ_ONCE(ssp->srcu_n_exp_nodelay) + 1);
- if (READ_ONCE(ssp->srcu_n_exp_nodelay) > srcu_max_nodelay_phase)
+ WRITE_ONCE(ssp->srcu_sup->srcu_n_exp_nodelay, READ_ONCE(ssp->srcu_sup->srcu_n_exp_nodelay) + 1);
+ if (READ_ONCE(ssp->srcu_sup->srcu_n_exp_nodelay) > srcu_max_nodelay_phase)
jbase = 1;
}
}
@@ -783,7 +783,7 @@ static void srcu_gp_start(struct srcu_struct *ssp)
rcu_seq_snap(&ssp->srcu_sup->srcu_gp_seq));
spin_unlock_rcu_node(sdp); /* Interrupts remain disabled. */
WRITE_ONCE(ssp->srcu_sup->srcu_gp_start, jiffies);
- WRITE_ONCE(ssp->srcu_n_exp_nodelay, 0);
+ WRITE_ONCE(ssp->srcu_sup->srcu_n_exp_nodelay, 0);
smp_mb(); /* Order prior store to ->srcu_gp_seq_needed vs. GP start. */
rcu_seq_start(&ssp->srcu_sup->srcu_gp_seq);
state = rcu_seq_state(ssp->srcu_sup->srcu_gp_seq);
@@ -1625,7 +1625,7 @@ static void srcu_advance_state(struct srcu_struct *ssp)
srcu_flip(ssp);
spin_lock_irq_rcu_node(ssp->srcu_sup);
rcu_seq_set_state(&ssp->srcu_sup->srcu_gp_seq, SRCU_STATE_SCAN2);
- ssp->srcu_n_exp_nodelay = 0;
+ ssp->srcu_sup->srcu_n_exp_nodelay = 0;
spin_unlock_irq_rcu_node(ssp->srcu_sup);
}
@@ -1640,7 +1640,7 @@ static void srcu_advance_state(struct srcu_struct *ssp)
mutex_unlock(&ssp->srcu_sup->srcu_gp_mutex);
return; /* readers present, retry later. */
}
- ssp->srcu_n_exp_nodelay = 0;
+ ssp->srcu_sup->srcu_n_exp_nodelay = 0;
srcu_gp_end(ssp); /* Releases ->srcu_gp_mutex. */
}
}