[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <86802c440807311121t47671674i356266d068f7e76a@mail.gmail.com>
Date: Thu, 31 Jul 2008 11:21:08 -0700
From: "Yinghai Lu" <yhlu.kernel@...il.com>
To: "Mike Travis" <travis@....com>
Cc: "Ingo Molnar" <mingo@...e.hu>,
"Thomas Gleixner" <tglx@...utronix.de>,
"H. Peter Anvin" <hpa@...or.com>,
"Eric W. Biederman" <ebiederm@...ssion.com>,
"Dhaval Giani" <dhaval@...ux.vnet.ibm.com>,
"Andrew Morton" <akpm@...ux-foundation.org>,
linux-kernel@...r.kernel.org, "Jack Steiner" <steiner@....com>
Subject: Re: [PATCH 0/3] dyn_array support #2
On Thu, Jul 31, 2008 at 9:32 AM, Mike Travis <travis@....com> wrote:
> Yinghai Lu wrote:
>> please check the patches adding dyn_array and nr_irqs #2
>>
>> Thanks
>>
>> YH
>
>
> It appears that the primary difference between your patch and Eric's
> is that you estimate the number of IRQ's required based on the number
> of cpus present, while Eric's patch grows the list based on the IRQ's
> being requested. For soon to be "power" desktop systems (say dual 8 core
> Nahalem's w/HT), you're reserving IRQ's for 32 cpus on a system which
> probably has one I/O bus (or maybe two). A dual socket Larabbee system
> will have 256 cpus. An SGI UV system has more of a "building block"
> approach, where you can grow all three (cpus, memory, I/O) independently.
>
> One other very nice feature of Eric's approach is that the new "IRQ"
> struct being requested can be created in "node local" memory, cutting
> down significantly the number of "cross node" accesses.
where is Eric's patch? I didn't get it...
>
> Plus, I still like Ingo's suggestion to not change NR_IRQS ==> nr_irqs.
> CONFIG_ARCH_HAS_DYNAMIC_IRQS spells out exactly what NR_IRQS means.
> (Even more accurate would be CONFIG_ARCH_HAS_DYNAMIC_NR_IRQS.)
not every array need to be changed to dyn_array, if the static array
is not big enough.
and some DEFINE_BIT map is using NR_IRQS.
>
> The DEFINE_DYN_ARRAY could be the following. (Changing general purpose
> DYN_ARRAY to specifically purposed IRQ_ARRAY.)
dyn_array is some more generic, and nr_irqs is one of it's user
>
> #ifdef CONFIG_ARCH_HAS_DYNAMIC_IRQS
> #define DEFINE_IRQ_ARRAY <new variable irq array [or list] definition>
> #else
> #define DEFINE_IRQ_ARRAY <old static irq array>
> #endif
>
> For the immediate problem, unraveling the code merge back to IRQ's based
> on NR_IOAPICS would seem to be the least intrusive.
less intrusive way could be use dyn_array and make nr_irqs to be set
via acpi_madt_oem_check...
YH
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists