[PATCH 4/9] softirq: Allow early break

From: Liu Jian
Date: Fri May 05 2023 - 07:25:00 EST


From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

Allow terminating the softirq processing loop without finishing the
vectors.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Liu Jian <liujian56@xxxxxxxxxx>
---
kernel/softirq.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/kernel/softirq.c b/kernel/softirq.c
index 48a81d8ae49a..e2cad5d108c8 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -582,6 +582,9 @@ asmlinkage __visible void __softirq_entry __do_softirq(void)
prev_count, preempt_count());
preempt_count_set(prev_count);
}
+
+ if (pending && __softirq_needs_break(start))
+ break;
}

if (!IS_ENABLED(CONFIG_PREEMPT_RT) &&
@@ -590,13 +593,14 @@ asmlinkage __visible void __softirq_entry __do_softirq(void)

local_irq_disable();

- pending = local_softirq_pending();
- if (pending) {
- if (!__softirq_needs_break(start) && --max_restart)
- goto restart;
+ if (pending)
+ or_softirq_pending(pending);
+ else if ((pending = local_softirq_pending()) &&
+ !__softirq_needs_break(start) &&
+ --max_restart)
+ goto restart;

- wakeup_softirqd();
- }
+ wakeup_softirqd();

account_softirq_exit(current);
lockdep_softirq_end(in_hardirq);
--
2.34.1