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UPSTREAM: rcu: Disable laziness if lazy-tracking says so

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During suspend, we see failures to suspend 1 in 300-500 suspends.
Looking closer, it appears that asynchronous RCU callbacks are being
queued as lazy even though synchronous callbacks are expedited. These
delays appear to not be very welcome by the suspend/resume code as
evidenced by these occasional suspend failures.

This commit modifies call_rcu() to check if rcu_async_should_hurry(),
which will return true if we are in suspend or in-kernel boot.

[ paulmck: Alphabetize local variables. ]

Ignoring the lazy hint makes the 3000 suspend/resume cycles pass
reliably on a 12th gen 12-core Intel CPU, and there is some evidence
that it also slightly speeds up boot performance.

Bug: 258241771
Bug: 222463781
Test: CQ
Fixes: 3cb278e73b ("rcu: Make call_rcu() lazy to save power")
Change-Id: I4cfe6f43de8bae9a6c034831c79d9773199d6d29
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
(cherry picked from commit cf7066b97e)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4318052
Reviewed-by: Sean Paul <sean@poorly.run>
Reviewed-by: Vineeth Pillai <vineethrp@google.com>
Tested-by: Joel Fernandes <joelaf@google.com>
Commit-Queue: Joel Fernandes <joelaf@google.com>
(cherry picked from commit e59686da91b689d3771a09f3eae37db5f40d3f75)
[Cherry picked from chromeos-5.15 tree. Minor tweaks to commit message
to match Android style]
Signed-off-by: Qais Yousef <qyousef@google.com>
This commit is contained in:
Joel Fernandes (Google)
2023-01-12 00:52:23 +00:00
committed by Treehugger Robot
parent 8568593719
commit 706e751b33
1 changed files with 3 additions and 1 deletions
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4
kernel/rcu/tree.c
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@@ -2977,10 +2977,11 @@ static void check_cb_ovld(struct rcu_data *rdp)
}
static void
__call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy)
__call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in)
{
static atomic_t doublefrees;
unsigned long flags;
bool lazy;
struct rcu_data *rdp;
bool was_alldone;
@@ -3005,6 +3006,7 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy)
local_irq_save(flags);
kasan_record_aux_stack_noalloc(head);
rdp = this_cpu_ptr(&rcu_data);
lazy = lazy_in && !rcu_async_should_hurry();
/* Add the callback to our list. */
if (unlikely(!rcu_segcblist_is_enabled(&rdp->cblist))) {