From: Ingo Molnar <mingo@elte.hu>
To: Dongdong Deng <dongdong.deng@windriver.com>
Cc: dzickus@redhat.com, peterz@infradead.org, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com, x86@kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [V3 PATCH] x86: avoid calling arch_trigger_all_cpu_backtrace() at the same time on SMP
Date: Thu, 11 Nov 2010 12:17:02 +0100 [thread overview]
Message-ID: <20101111111702.GA12644@elte.hu> (raw)
In-Reply-To: <1289473307-7965-1-git-send-email-dongdong.deng@windriver.com>
Hm, another thing i noticed is that there's two of these:
> #ifdef ARCH_HAS_NMI_WATCHDOG
> +/* "in progress" flag of arch_trigger_all_cpu_backtrace */
> +static unsigned long backtrace_flag;
> +
> void arch_trigger_all_cpu_backtrace(void)
> {
> int i;
> + unsigned long flags;
> +
> + /*
> + * Have to disable irq here, as the
> + * arch_trigger_all_cpu_backtrace() could be
> + * triggered by "spin_lock()" with irqs on.
> + */
> + local_irq_save(flags);
> +/* "in progress" flag of arch_trigger_all_cpu_backtrace */
> +static unsigned long backtrace_flag;
> +
> void arch_trigger_all_cpu_backtrace(void)
> {
> int i;
> + unsigned long flags;
> +
> + /*
> + * Have to disable irq here, as the
> + * arch_trigger_all_cpu_backtrace() could be
> + * triggered by "spin_lock()" with irqs on.
> + */
> + local_irq_save(flags);
> +
> + if (test_and_set_bit(0, &backtrace_flag))
A fair amount of code is being duplicated in two places - which is not nice. Lets
try to create a shared facility instead?
Thanks,
Ingo
next prev parent reply other threads:[~2010-11-11 11:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-11 11:01 [V3 PATCH] x86: avoid calling arch_trigger_all_cpu_backtrace() at the same time on SMP Dongdong Deng
2010-11-11 11:17 ` Ingo Molnar [this message]
2010-11-11 11:23 ` DDD
2010-11-11 12:12 ` Dongdong Deng
2010-11-11 14:34 ` Don Zickus
2010-11-11 18:06 ` Ingo Molnar
2010-11-12 2:38 ` DDD
2010-11-12 3:39 ` Don Zickus
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