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Groups > linux.kernel > #1260499
| From | Vineet Gupta <Vineet.Gupta1@synopsys.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v1 05/20] ARC: rwlock: disable interrupts in !LLSC variant |
| Date | 2015-11-02 10:50 +0100 |
| Message-ID | <qqjUt-3G6-11@gated-at.bofh.it> (permalink) |
| References | <qpEeC-3hu-3@gated-at.bofh.it> <qqjrs-3wz-29@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Saturday 31 October 2015 06:45 PM, Noam Camus wrote:
> From: Noam Camus <noamc@ezchip.com>
>
> If we hold rw->lock_mutex and interrupt occures we may
> end up spinning on it for ever during softirq.
>
> Below you may see an example for interrupt we get while
> nl_table_lock is holding its rw->lock_mutex and we spinned
> on it for ever.
>
> The concept for the fix was taken from SPARC.
>
> [2015-05-12 19:16:12] Stack Trace:
> [2015-05-12 19:16:12] arc_unwind_core+0xb8/0x11c
> [2015-05-12 19:16:12] dump_stack+0x68/0xac
> [2015-05-12 19:16:12] _raw_read_lock+0xa8/0xac
> [2015-05-12 19:16:12] netlink_broadcast_filtered+0x56/0x35c
> [2015-05-12 19:16:12] nlmsg_notify+0x42/0xa4
> [2015-05-12 19:16:13] neigh_update+0x1fe/0x44c
> [2015-05-12 19:16:13] neigh_event_ns+0x40/0xa4
> [2015-05-12 19:16:13] arp_process+0x46e/0x5a8
> [2015-05-12 19:16:13] __netif_receive_skb_core+0x358/0x500
> [2015-05-12 19:16:13] process_backlog+0x92/0x154
> [2015-05-12 19:16:13] net_rx_action+0xb8/0x188
> [2015-05-12 19:16:13] __do_softirq+0xda/0x1d8
> [2015-05-12 19:16:14] irq_exit+0x8a/0x8c
> [2015-05-12 19:16:14] arch_do_IRQ+0x6c/0xa8
> [2015-05-12 19:16:14] handle_interrupt_level1+0xe4/0xf0
>
> Signed-off-by: Noam Camus <noamc@ezchip.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> ---
> arch/arc/include/asm/spinlock.h | 14 ++++++++++++++
> 1 files changed, 14 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arc/include/asm/spinlock.h b/arch/arc/include/asm/spinlock.h
> index db8c59d..800e7c4 100644
> --- a/arch/arc/include/asm/spinlock.h
> +++ b/arch/arc/include/asm/spinlock.h
> @@ -610,7 +610,9 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock)
> static inline int arch_read_trylock(arch_rwlock_t *rw)
> {
> int ret = 0;
> + unsigned long flags;
>
> + local_irq_save(flags);
> arch_spin_lock(&(rw->lock_mutex));
>
> /*
> @@ -623,6 +625,7 @@ static inline int arch_read_trylock(arch_rwlock_t *rw)
> }
>
> arch_spin_unlock(&(rw->lock_mutex));
> + local_irq_restore(flags);
>
> smp_mb();
> return ret;
> @@ -632,7 +635,9 @@ static inline int arch_read_trylock(arch_rwlock_t *rw)
> static inline int arch_write_trylock(arch_rwlock_t *rw)
> {
> int ret = 0;
> + unsigned long flags;
>
> + local_irq_save(flags);
> arch_spin_lock(&(rw->lock_mutex));
>
> /*
> @@ -646,6 +651,7 @@ static inline int arch_write_trylock(arch_rwlock_t *rw)
> ret = 1;
> }
> arch_spin_unlock(&(rw->lock_mutex));
> + local_irq_restore(flags);
>
> return ret;
> }
> @@ -664,16 +670,24 @@ static inline void arch_write_lock(arch_rwlock_t *rw)
>
> static inline void arch_read_unlock(arch_rwlock_t *rw)
> {
> + unsigned long flags;
> +
> + local_irq_save(flags);
> arch_spin_lock(&(rw->lock_mutex));
Isn't raw_spin_lock_irqsave() equivalent and more concise ?
> rw->counter++;
> arch_spin_unlock(&(rw->lock_mutex));
> + local_irq_restore(flags);
> }
>
> static inline void arch_write_unlock(arch_rwlock_t *rw)
> {
> + unsigned long flags;
> +
> + local_irq_save(flags);
> arch_spin_lock(&(rw->lock_mutex));
> rw->counter = __ARCH_RW_LOCK_UNLOCKED__;
> arch_spin_unlock(&(rw->lock_mutex));
> + local_irq_restore(flags);
> }
>
> #endif
>
--
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[PATCH v1 00/20] eznps a new ARC platform Noam Camus <noamc@ezchip.com> - 2015-10-31 14:20 +0100
Re: [PATCH v1 02/20] clocksource: Add NPS400 timers driver Daniel Lezcano <daniel.lezcano@linaro.org> - 2015-11-01 21:50 +0100
RE: [PATCH v1 02/20] clocksource: Add NPS400 timers driver Noam Camus <noamc@ezchip.com> - 2015-11-02 09:00 +0100
RE: [PATCH v1 07/20] ARC: mm: use generic macros _BITUL() Noam Camus <noamc@ezchip.com> - 2015-11-02 07:30 +0100
Re: [PATCH v1 07/20] ARC: mm: use generic macros _BITUL() Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 07:30 +0100
Re: [PATCH v1 09/20] ARC: add CONFIG_CLKSRC_OF support to time_init() Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 07:40 +0100
Re: [PATCH v1 08/20] ARC: Use res_service as entry point for secondaries Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 07:40 +0100
RE: [PATCH v1 08/20] ARC: Use res_service as entry point for secondaries Noam Camus <noamc@ezchip.com> - 2015-11-02 09:10 +0100
Re: [PATCH v1 19/20] ARC: [plat-eznps] replace sync with proper cpu barrier Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 08:50 +0100
Re: [PATCH v1 19/20] ARC: [plat-eznps] replace sync with proper cpu barrier Peter Zijlstra <peterz@infradead.org> - 2015-11-02 10:30 +0100
Re: [PATCH v1 16/20] ARC: [plat-eznps] Use dedicated cpu_relax() Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 09:00 +0100
Re: [PATCH v1 18/20] ARC: [plat-eznps] define IPI_IRQ Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 09:00 +0100
RE: [PATCH v1 18/20] ARC: [plat-eznps] define IPI_IRQ Noam Camus <noamc@ezchip.com> - 2015-11-02 13:20 +0100
Re: [PATCH v1 14/20] ARC: [plat-eznps] Use dedicated SMP barriers Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 09:10 +0100
RE: [PATCH v1 14/20] ARC: [plat-eznps] Use dedicated SMP barriers Noam Camus <noamc@ezchip.com> - 2015-11-02 14:10 +0100
Re: [PATCH v1 05/20] ARC: rwlock: disable interrupts in !LLSC variant Peter Zijlstra <peterz@infradead.org> - 2015-11-02 10:20 +0100
Re: [PATCH v1 16/20] ARC: [plat-eznps] Use dedicated cpu_relax() Peter Zijlstra <peterz@infradead.org> - 2015-11-02 10:30 +0100
RE: [PATCH v1 16/20] ARC: [plat-eznps] Use dedicated cpu_relax() Noam Camus <noamc@ezchip.com> - 2015-11-03 15:10 +0100
Re: [PATCH v1 05/20] ARC: rwlock: disable interrupts in !LLSC variant Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 10:50 +0100
Re: [PATCH v1 05/20] ARC: rwlock: disable interrupts in !LLSC variant Peter Zijlstra <peterz@infradead.org> - 2015-11-02 11:10 +0100
Re: [PATCH v1 11/20] ARC: [plat-eznps] Add eznps platform Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 12:00 +0100
RE: [PATCH v1 11/20] ARC: [plat-eznps] Add eznps platform Noam Camus <noamc@ezchip.com> - 2015-11-03 17:10 +0100
RE: [PATCH v1 11/20] ARC: [plat-eznps] Add eznps platform Noam Camus <noamc@ezchip.com> - 2015-11-04 13:40 +0100
Re: [PATCH v1 02/20] clocksource: Add NPS400 timers driver Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 12:10 +0100
RE: [PATCH v1 02/20] clocksource: Add NPS400 timers driver Noam Camus <noamc@ezchip.com> - 2015-11-03 17:10 +0100
Re: [PATCH v1 20/20] ARC: Add eznps platform to Kconfig and Makefile Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 12:10 +0100
RE: [PATCH v1 20/20] ARC: Add eznps platform to Kconfig and Makefile Noam Camus <noamc@ezchip.com> - 2015-11-03 16:40 +0100
Re: [PATCH v1 13/20] ARC: [plat-eznps] Use dedicated bitops/atomic/cmpxchg Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-02 13:00 +0100
Re: [PATCH v1 00/20] eznps a new ARC platform Vineet Gupta <vgupta@synopsys.com> - 2015-11-04 16:40 +0100
RE: [PATCH v1 00/20] eznps a new ARC platform Noam Camus <noamc@ezchip.com> - 2015-11-04 17:00 +0100
RE: [PATCH v1 00/20] eznps a new ARC platform Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-04 18:50 +0100
Re: [PATCH v1 11/20] ARC: [plat-eznps] Add eznps platform Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-05 06:20 +0100
Re: [PATCH v2 03/19] clocksource: Add NPS400 timers driver Thomas Gleixner <tglx@linutronix.de> - 2015-11-07 12:30 +0100
Re: [PATCH v2 04/19] irqchip: add nps Internal and external irqchips Thomas Gleixner <tglx@linutronix.de> - 2015-11-07 12:40 +0100
Re: [PATCH v2 04/19] irqchip: add nps Internal and external irqchips Noam Camus <noamc@ezchip.com> - 2015-11-07 22:00 +0100
Re: [PATCH v2 04/19] irqchip: add nps Internal and external irqchips Thomas Gleixner <tglx@linutronix.de> - 2015-11-08 01:00 +0100
Re: [PATCH v2 16/19] ARC: [plat-eznps] Use dedicated cpu_relax() Peter Zijlstra <peterz@infradead.org> - 2015-11-09 11:10 +0100
Re: [PATCH v2 16/19] ARC: [plat-eznps] Use dedicated cpu_relax() Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-11-09 11:30 +0100
Re: [PATCH v2 16/19] ARC: [plat-eznps] Use dedicated cpu_relax() Peter Zijlstra <peterz@infradead.org> - 2015-11-09 11:50 +0100
Re: [PATCH v2 16/19] ARC: [plat-eznps] Use dedicated cpu_relax() Vineet Gupta <vgupta@synopsys.com> - 2015-11-09 13:30 +0100
Re: [PATCH v2 16/19] ARC: [plat-eznps] Use dedicated cpu_relax() Peter Zijlstra <peterz@infradead.org> - 2015-11-09 14:00 +0100
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