From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Marc Zyngier <maz@kernel.org>, Rich Felker <dalias@libc.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Paul McKenney <paulmck@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
linux-sh@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
Richard Weinberger <richard@nod.at>,
Frederic Weisbecker <frederic@kernel.org>,
Valentin Schneider <valentin.schneider@arm.com>,
Jeff Dike <jdike@addtoit.com>,
Russell King <linux@armlinux.org.uk>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
linux-parisc@vger.kernel.org, Helge Deller <deller@gmx.de>,
linux-um@lists.infradead.org, Will Deacon <will@kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
linux-arm-kernel@lists.infradead.org,
Anton Ivanov <anton.ivanov@cambridgegreys.com>
Subject: [patch 13/19] softirq: Move various protections into inline helpers
Date: Fri, 13 Nov 2020 15:02:20 +0100 [thread overview]
Message-ID: <20201113141734.207605126@linutronix.de> (raw)
In-Reply-To: 20201113140207.499353218@linutronix.de
To allow reuse of the bulk of softirq processing code for RT and to avoid
#ifdeffery all over the place, split protections for various code sections
out into inline helpers so the RT variant can just replace them in one go.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/softirq.c | 53 ++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 44 insertions(+), 9 deletions(-)
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -204,6 +204,42 @@ void __local_bh_enable_ip(unsigned long
}
EXPORT_SYMBOL(__local_bh_enable_ip);
+static inline void local_bh_disable_irq_enter(void)
+{
+ local_bh_disable();
+}
+
+static inline void local_bh_enable_irq_enter(void)
+{
+ _local_bh_enable();
+}
+
+static inline void softirq_handle_begin(void)
+{
+ __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET);
+}
+
+static inline void softirq_handle_end(void)
+{
+ __local_bh_enable(SOFTIRQ_OFFSET);
+ WARN_ON_ONCE(in_interrupt());
+}
+
+static inline void ksoftirqd_run_begin(void)
+{
+ local_irq_disable();
+}
+
+static inline void ksoftirqd_run_end(void)
+{
+ local_irq_enable();
+}
+
+static inline bool should_wake_ksoftirqd(void)
+{
+ return true;
+}
+
static inline void invoke_softirq(void)
{
if (ksoftirqd_running(local_softirq_pending()))
@@ -317,7 +353,7 @@ asmlinkage __visible void __softirq_entr
pending = local_softirq_pending();
account_irq_enter_time(current);
- __local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET);
+ softirq_handle_begin();
in_hardirq = lockdep_softirq_start();
restart:
@@ -367,8 +403,7 @@ asmlinkage __visible void __softirq_entr
lockdep_softirq_end(in_hardirq);
account_irq_exit_time(current);
- __local_bh_enable(SOFTIRQ_OFFSET);
- WARN_ON_ONCE(in_interrupt());
+ softirq_handle_end();
current_restore_flags(old_flags, PF_MEMALLOC);
}
@@ -382,9 +417,9 @@ void irq_enter_rcu(void)
* Prevent raise_softirq from needlessly waking up ksoftirqd
* here, as softirq will be serviced on return from interrupt.
*/
- local_bh_disable();
+ local_bh_disable_irq_enter();
tick_irq_enter();
- _local_bh_enable();
+ local_bh_enable_irq_enter();
}
__irq_enter();
}
@@ -467,7 +502,7 @@ inline void raise_softirq_irqoff(unsigne
* Otherwise we wake up ksoftirqd to make sure we
* schedule the softirq soon.
*/
- if (!in_interrupt())
+ if (!in_interrupt() && should_wake_ksoftirqd())
wakeup_softirqd();
}
@@ -645,18 +680,18 @@ static int ksoftirqd_should_run(unsigned
static void run_ksoftirqd(unsigned int cpu)
{
- local_irq_disable();
+ ksoftirqd_run_begin();
if (local_softirq_pending()) {
/*
* We can safely run softirq on inline stack, as we are not deep
* in the task stack here.
*/
__do_softirq();
- local_irq_enable();
+ ksoftirqd_run_end();
cond_resched();
return;
}
- local_irq_enable();
+ ksoftirqd_run_end();
}
#ifdef CONFIG_HOTPLUG_CPU
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next prev parent reply other threads:[~2020-11-13 14:28 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-13 14:02 [patch 00/19] softirq: Cleanups and RT awareness Thomas Gleixner
2020-11-13 14:02 ` [patch 01/19] parisc: Remove bogus __IRQ_STAT macro Thomas Gleixner
2020-11-13 14:02 ` [patch 02/19] sh: Get rid of nmi_count() Thomas Gleixner
2021-01-01 14:27 ` John Paul Adrian Glaubitz
2020-11-13 14:02 ` [patch 03/19] irqstat: Get rid of nmi_count() and __IRQ_STAT() Thomas Gleixner
2020-11-13 14:02 ` [patch 04/19] um/irqstat: Get rid of the duplicated declarations Thomas Gleixner
2020-11-13 14:02 ` [patch 05/19] ARM: irqstat: Get rid of duplicated declaration Thomas Gleixner
2020-11-16 18:19 ` Valentin Schneider
2020-11-13 14:02 ` [patch 06/19] arm64: " Thomas Gleixner
2020-11-16 10:01 ` Will Deacon
2020-11-16 10:51 ` Marc Zyngier
2020-11-13 14:02 ` [patch 07/19] asm-generic/irqstat: Add optional __nmi_count member Thomas Gleixner
2020-11-13 14:02 ` [patch 08/19] sh: irqstat: Use the generic irq_cpustat_t Thomas Gleixner
2020-11-13 14:02 ` [patch 09/19] irqstat: Move declaration into asm-generic/hardirq.h Thomas Gleixner
2020-11-13 14:02 ` [patch 10/19] preempt: Cleanup the macro maze a bit Thomas Gleixner
2020-11-16 12:17 ` Peter Zijlstra
2020-11-16 17:42 ` Thomas Gleixner
2020-11-17 10:21 ` Peter Zijlstra
2020-11-13 14:02 ` [patch 11/19] softirq: Move related code into one section Thomas Gleixner
2020-11-19 12:20 ` Frederic Weisbecker
2020-11-13 14:02 ` [patch 12/19] softirq: Add RT specific softirq accounting Thomas Gleixner
2020-11-19 12:18 ` Frederic Weisbecker
2020-11-19 18:34 ` Thomas Gleixner
2020-11-19 22:52 ` Frederic Weisbecker
2020-11-13 14:02 ` Thomas Gleixner [this message]
2020-11-13 14:02 ` [patch 14/19] softirq: Make softirq control and processing RT aware Thomas Gleixner
2020-11-20 0:26 ` Frederic Weisbecker
2020-11-20 13:27 ` Thomas Gleixner
2020-11-23 13:44 ` Frederic Weisbecker
2020-11-23 19:27 ` Thomas Gleixner
2020-11-23 19:56 ` Frederic Weisbecker
2020-11-23 23:58 ` Frederic Weisbecker
2020-11-24 0:06 ` Thomas Gleixner
2020-11-24 0:13 ` Frederic Weisbecker
2020-11-24 0:22 ` Thomas Gleixner
2020-11-13 14:02 ` [patch 15/19] tick/sched: Prevent false positive softirq pending warnings on RT Thomas Gleixner
2020-11-13 14:02 ` [patch 16/19] rcu: Prevent false positive softirq warning " Thomas Gleixner
2020-11-13 14:02 ` [patch 17/19] softirq: Replace barrier() with cpu_relax() in tasklet_unlock_wait() Thomas Gleixner
2020-11-13 14:02 ` [patch 18/19] tasklets: Use static inlines for stub implementations Thomas Gleixner
2020-11-13 14:02 ` [patch 19/19] tasklets: Prevent kill/unlock_wait deadlock on RT Thomas Gleixner
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