Re: [patch] 2.6.6-rc2 Allow architectures to reenable interrupts on contended spinlocks

[Keith Owens]

On Mon, 26 Apr 2004 21:49:52 -0700, 
Andrew Morton <akpm@xxxxxxxx> wrote:
>Keith Owens <kaos@xxxxxxx> wrote:
>>
>>  Enable interrupts while waiting for a disabled spinlock, but only if
>>  interrupts were enabled before issuing spin_lock_irqsave().  It makes a
>>  measurable difference to interrupt servicing on large systems.
>
>Do you know which are the offending locks?

Workload dependent.  We already service interrupts while waiting for a
non-disabled spinlock.  The patch allows a cpu to do some useful work
and service interrupts while waiting for disabled spinlocks as well.

>How much difference, and how large are the systems?

>From memory (September 2003) 3-5% improvement on an AIM7 run, with 64
processors.

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