From: qianjun.kernel@gmail.com
To: tglx@linutronix.de, peterz@infradead.org, will@kernel.org,
luto@kernel.org, linux-kernel@vger.kernel.org
Cc: laoar.shao@gmail.com, qais.yousef@arm.com, urezki@gmail.com,
jun qian <qianjun.kernel@gmail.com>
Subject: [PATCH V7 3/4] softirq: Rewrite softirq processing loop
Date: Tue, 15 Sep 2020 19:56:08 +0800 [thread overview]
Message-ID: <20200915115609.85106-4-qianjun.kernel@gmail.com> (raw)
In-Reply-To: <20200915115609.85106-1-qianjun.kernel@gmail.com>
From: jun qian <qianjun.kernel@gmail.com>
Simplify the softirq processing loop by using the bitmap APIs
Signed-off-by: jun qian <qianjun.kernel@gmail.com>
---
kernel/softirq.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 5a627cd..cbb59b5 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -260,9 +260,9 @@ asmlinkage __visible void __softirq_entry __do_softirq(void)
unsigned long old_flags = current->flags;
unsigned int max_restart = MAX_SOFTIRQ_RESTART;
struct softirq_action *h;
+ unsigned long pending;
+ unsigned int vec_nr;
bool in_hardirq;
- __u32 pending;
- int softirq_bit;
/*
* Mask out PF_MEMALLOC as the current task context is borrowed for the
@@ -283,15 +283,13 @@ asmlinkage __visible void __softirq_entry __do_softirq(void)
local_irq_enable();
- h = softirq_vec;
-
- while ((softirq_bit = ffs(pending))) {
- unsigned int vec_nr;
+ for_each_set_bit(vec_nr, &pending, NR_SOFTIRQS) {
int prev_count;
- h += softirq_bit - 1;
+ __clear_bit(vec_nr, &pending);
+
+ h = softirq_vec + vec_nr;
- vec_nr = h - softirq_vec;
prev_count = preempt_count();
kstat_incr_softirqs_this_cpu(vec_nr);
@@ -305,8 +303,6 @@ asmlinkage __visible void __softirq_entry __do_softirq(void)
prev_count, preempt_count());
preempt_count_set(prev_count);
}
- h++;
- pending >>= softirq_bit;
}
if (__this_cpu_read(ksoftirqd) == current)
--
1.8.3.1
next prev parent reply other threads:[~2020-09-15 12:19 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-15 11:56 [PATCH V7 0/4] Softirq:avoid large sched delay from the pending softirqs qianjun.kernel
2020-09-15 11:56 ` [PATCH V7 1/4] softirq: Use sched_clock() based timeout qianjun.kernel
2020-09-24 8:34 ` Thomas Gleixner
2020-09-15 11:56 ` [PATCH V7 2/4] softirq: Factor loop termination condition qianjun.kernel
2020-09-24 8:36 ` Thomas Gleixner
2020-09-24 12:31 ` Thomas Gleixner
2020-09-15 11:56 ` qianjun.kernel [this message]
2020-09-15 11:56 ` [PATCH V7 4/4] softirq: Allow early break the softirq processing loop qianjun.kernel
2020-09-24 15:37 ` Thomas Gleixner
2020-09-24 23:08 ` Frederic Weisbecker
2020-09-24 23:10 ` Frederic Weisbecker
2020-09-25 22:37 ` Thomas Gleixner
2020-09-25 0:42 ` Frederic Weisbecker
2020-09-25 22:42 ` Thomas Gleixner
2020-09-26 12:22 ` Frederic Weisbecker
2020-09-28 10:51 ` jun qian
2020-09-29 11:44 ` Frederic Weisbecker
2020-10-09 15:01 ` Qais Yousef
2020-10-13 10:43 ` Frederic Weisbecker
2020-10-13 12:40 ` Qais Yousef
2020-09-26 2:00 ` jun qian
2020-09-27 1:05 ` [softirq] 56c21abbe6: will-it-scale.per_process_ops -9.1% regression kernel test robot
2020-09-28 9:20 ` [PATCH V7 4/4] softirq: Allow early break the softirq processing loop Peter Zijlstra
2020-09-28 11:15 ` jun qian
2020-09-28 9:22 ` Peter Zijlstra
2020-09-28 10:09 ` Thomas Gleixner
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