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Message-ID: <86802c440807312020nb8ba0ddr6595139cfceb1b52@mail.gmail.com>
Date: Thu, 31 Jul 2008 20:20:35 -0700
From: "Yinghai Lu" <yhlu.kernel@gmail.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH] serial: change remove NR_IRQS in 8250.c
Cc: "Ingo Molnar" <mingo@elte.hu>, "Thomas Gleixner" <tglx@linutronix.de>,
       "H. Peter Anvin" <hpa@zytor.com>,
       "Dhaval Giani" <dhaval@linux.vnet.ibm.com>,
       "Mike Travis" <travis@sgi.com>,
       "Andrew Morton" <akpm@linux-foundation.org>,
       linux-kernel@vger.kernel.org
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On Thu, Jul 31, 2008 at 4:50 AM, Eric W. Biederman
<ebiederm@xmission.com> wrote:
>> replace
>>       [PATCH] serial: change irq_lists to use dyn_array
>> use small array with index to handle irq locking for serial port
>> hope 32 slot is enough
>
> Could you size this array by NR_UARTS (our worst case usage)

how about crazy user set that too big?

> and place irq_no in struct irq_info?
should be ok
>
> Also you want to hold irq_info->lock when you set or clear irq_no.
> Just to be on the safe side.  I expect we can avoid clearing the irq_no
> in the irq_lists and prevent a few more races from being a possibility.

will try

YH