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From: "H. Peter Anvin" <hpa@zytor.com>
To: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
	Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
	Yinghai Lu <yinghai@kernel.org>,
	"Maciej W. Rozycki" <macro@linux-mips.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [patch] x86, apic: use 0x20 for the IRQ_MOVE_CLEANUP_VECTOR instead of 0x1f
Date: Mon, 11 Jan 2010 16:13:46 -0800	[thread overview]
Message-ID: <4B4BBEBA.4060403@zytor.com> (raw)
In-Reply-To: <1263254812.2859.890.camel@sbs-t61.sc.intel.com>

On 01/11/2010 04:06 PM, Suresh Siddha wrote:
>>
>> Yes, that's what I said.  My question was to Suresh what enforces that
>> in the case of his patch, which moves the legacy range into the middle
>> of the device vectors.
> 
> It's not the used_vector bitmap. That range will appear as used on all
> the cpu's and hence we won't be allocating it for anything else.
> 

OK, fair enough.

> Now the question is: for non-legacy (io-apic) case, instead of reserving
> this range for all the cpu's, does it make sense to generalize like any
> other vector?

It sounds like something that we could experiment with -- after
switching an IRQ to ioapic mode, make it a movable interrupt.  It
*seems* it should work, but it's scary stuff to muck with.

Eric, do you see any reason why it wouldn't work?  I truly couldn't
understand your previous remark, especially the bit about "it is
dangerous to play lowest priority irq games in that range".

	-hpa



  reply	other threads:[~2010-01-12  0:14 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-09  2:09 [patch] x86, apic: use 0x20 for the IRQ_MOVE_CLEANUP_VECTOR instead of 0x1f Suresh Siddha
2010-01-09  2:19 ` H. Peter Anvin
2010-01-09  2:50   ` Yinghai Lu
2010-01-11 22:53   ` Suresh Siddha
2010-01-11 22:57     ` H. Peter Anvin
2010-01-11 23:10       ` Eric W. Biederman
2010-01-11 23:13         ` H. Peter Anvin
2010-01-12  0:06           ` Suresh Siddha
2010-01-12  0:13             ` H. Peter Anvin [this message]
2010-01-12  0:28               ` Eric W. Biederman
2010-01-12  0:36                 ` H. Peter Anvin
2010-01-12  1:52                   ` Eric W. Biederman
2010-01-12  2:17                     ` H. Peter Anvin
2010-01-12  2:27                       ` Eric W. Biederman
2010-01-12 10:25                       ` Alan Cox
2010-01-13 20:36                       ` Eric W. Biederman
2010-01-13 20:38                         ` H. Peter Anvin
2010-01-13 20:53                         ` H. Peter Anvin
2010-01-13 20:58                         ` H. Peter Anvin
2010-01-12  0:42                 ` H. Peter Anvin
2010-01-11 23:00     ` Eric W. Biederman
2010-01-11 23:07       ` H. Peter Anvin
2010-01-09  3:07 ` Yinghai Lu
2010-01-09  3:20   ` H. Peter Anvin
2010-01-09  3:23 ` H. Peter Anvin

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