[lkml]   [2014]   [Apr]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] irq: crossbar: improve allocate_free_irq() complexity
On Tue, Apr 01, 2014 at 05:44:19PM -0500, Felipe Balbi wrote:
> current algorithm in allocate_free_irq() is O(n),
> by just keeping track of last allocated IRQ with a
> simple unsigned integer, we can find a free IRQ
> in O(1).
> Signed-off-by: Felipe Balbi <>
> ---
> compile-tested only as J6 DTS is currently missing crossbar
> altogether :-(
> There's a drawback with this patch which I'm not sure if we
> should care a lot because I couldn't entirely grasp when is
> domain->xlate() called and if we will map/unmap IRQs in runtime
> or will this *always* be done only during boot.
> If we're talking about runtime IRQ remapping, then this, clearly,
> won't work. But if this will be done only during boot up, then we
> avoid iterating over the irq_map array each time we try to translate
> a new IRQ prior to mapping it.
> Comments are highly welcome as I'll probably learn something new
> about the IRQ subsystem ;-)

do not apply this one!!! It won't work in all cases.

[unhandled content-type:application/pgp-signature]
 \ /
  Last update: 2014-04-11 00:21    [W:0.030 / U:2.252 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site