Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [PATCH 4/5] srcu: No need to advance/accelerate if no callback enqueued | Date | Wed, 4 Oct 2023 01:29:02 +0200 |
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While in grace period start, there is nothing to accelerate and therefore no need to advance the callbacks either if no callback is to be enqueued.
Spare these needless operations in this case.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org> --- kernel/rcu/srcutree.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index e9356a103626..2bfc8ed1eed2 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -1261,9 +1261,11 @@ static unsigned long srcu_gp_start_if_needed(struct srcu_struct *ssp, * period (gp_num = X + 8). So acceleration fails. */ s = rcu_seq_snap(&ssp->srcu_sup->srcu_gp_seq); - rcu_segcblist_advance(&sdp->srcu_cblist, - rcu_seq_current(&ssp->srcu_sup->srcu_gp_seq)); - WARN_ON_ONCE(!rcu_segcblist_accelerate(&sdp->srcu_cblist, s) && rhp); + if (rhp) { + rcu_segcblist_advance(&sdp->srcu_cblist, + rcu_seq_current(&ssp->srcu_sup->srcu_gp_seq)); + WARN_ON_ONCE(!rcu_segcblist_accelerate(&sdp->srcu_cblist, s)); + } if (ULONG_CMP_LT(sdp->srcu_gp_seq_needed, s)) { sdp->srcu_gp_seq_needed = s; needgp = true; -- 2.41.0
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