Re: [PATCH 0/3] dyn_array support #2

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From: Mike Travis
Date: Thursday, July 31, 2008 - 9:32 am

Yinghai Lu wrote:


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.

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.)

The DEFINE_DYN_ARRAY could be the following.  (Changing general purpose
DYN_ARRAY to specifically purposed IRQ_ARRAY.)

#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.

Thanks,
Mike
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Messages in current thread:
[PATCH] x86: 64bit support more than 256 irq v2, Yinghai Lu, (Tue Jul 29, 2:14 pm)
Re: [PATCH] x86: 64bit support more than 256 irq v2, Yinghai Lu, (Tue Jul 29, 3:16 pm)
Re: [PATCH] x86: 64bit support more than 256 irq v2, Eric W. Biederman, (Tue Jul 29, 4:22 pm)
RFC [PATCH] x86: introduce nr_irqs for 64bit, Yinghai Lu, (Tue Jul 29, 9:38 pm)
Re: RFC [PATCH] x86: introduce nr_irqs for 64bit, Ingo Molnar, (Wed Jul 30, 3:09 am)
[PATCH] x86: introduce nr_irqs for 64bit v2, Yinghai Lu, (Wed Jul 30, 3:11 am)
Re: RFC [PATCH] x86: introduce nr_irqs for 64bit, Yinghai Lu, (Wed Jul 30, 3:16 am)
Re: RFC [PATCH] x86: introduce nr_irqs for 64bit, Mike Travis, (Wed Jul 30, 5:58 am)
[PATCH 0/7] dyn_array support, Yinghai Lu, (Wed Jul 30, 12:10 pm)
[PATCH 2/7] x86: introduce nr_irqs for 64bit v3, Yinghai Lu, (Wed Jul 30, 12:13 pm)
[PATCH 5/7] pci: make irq2_iommu to use dyn_array, Yinghai Lu, (Wed Jul 30, 12:16 pm)
[PATCH 7/7] x86: make 64bit support dyn_array, Yinghai Lu, (Wed Jul 30, 12:18 pm)
[PATCH 1/7] x86: 64bit support more than 256 irq v1, Yinghai Lu, (Wed Jul 30, 12:27 pm)
[PATCH 3/7] add dyn_array support, Yinghai Lu, (Wed Jul 30, 12:37 pm)
[PATCH 6/7] irq: make irq_desc to use dyn_array, Yinghai Lu, (Wed Jul 30, 12:40 pm)
[PATCH 0/3] dyn_array support #2, Yinghai Lu, (Wed Jul 30, 9:09 pm)
[PATCH 2/3] add per_cpu_dyn_array support, Yinghai Lu, (Wed Jul 30, 9:11 pm)
Re: [PATCH 1/3] serial: change irq_lists to use dyn_array, Eric W. Biederman, (Wed Jul 30, 10:58 pm)
[PATCH] serial: change remove NR_IRQS in 8250.c, Yinghai Lu, (Thu Jul 31, 1:26 am)
[PATCH] x86 remove irq_vectors_limit.h, Yinghai Lu, (Thu Jul 31, 3:14 am)
Re: [PATCH] serial: change remove NR_IRQS in 8250.c, Eric W. Biederman, (Thu Jul 31, 4:50 am)
Re: [PATCH 0/3] dyn_array support #2, Mike Travis, (Thu Jul 31, 9:32 am)
Re: [PATCH] serial: change remove NR_IRQS in 8250.c, Eric W. Biederman, (Thu Jul 31, 11:10 am)
Re: [PATCH 0/3] dyn_array support #2, Yinghai Lu, (Thu Jul 31, 11:21 am)
Re: [PATCH 0/3] dyn_array support #2, Peter Zijlstra, (Thu Jul 31, 2:51 pm)
Re: [PATCH 0/3] dyn_array support #2, Yinghai Lu, (Thu Jul 31, 3:07 pm)
Re: [PATCH 0/3] dyn_array support #2, Eric W. Biederman, (Thu Jul 31, 3:14 pm)
Re: [PATCH 0/3] dyn_array support #2, Yinghai Lu, (Thu Jul 31, 3:25 pm)
Re: [PATCH] serial: change remove NR_IRQS in 8250.c, Yinghai Lu, (Thu Jul 31, 8:20 pm)
Re: [PATCH 0/3] dyn_array support #2, Yinghai Lu, (Thu Jul 31, 8:52 pm)
Re: [PATCH 0/7] dyn_array support, Eric W. Biederman, (Fri Aug 1, 1:13 pm)