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    SubjectRe: [PATCH] create /proc/all-interrupts
    On Mon, Jul 30, 2007 at 12:32:06PM -0700, Andrew Morton wrote:
    > On Mon, 30 Jul 2007 10:33:17 -0700
    > Sven-Thorsten Dietrich <sdietrich@novell.com> wrote:
    > > On Thu, 2007-07-26 at 11:56 -0700, H. Peter Anvin wrote:
    > > > Joe Korty wrote:
    > > > > Create /proc/all-interrupts for some architectures.

    > > Would it make sense to drop this patch into -mm for feedback?
    > >
    >
    > It's a lot of code for something which might be useful to someone sometime.
    >
    > It's a bit of a crappy changelog too. I'd at least like to see a list of
    > all the new fields.
    >
    > It should be OK to add new lines to /proc/interrupts? That file varies a
    > lot between machines adn between architectures - as long as the new lines
    > have similar layout it is unlikely that anything will break.
    >
    > + atomic_inc(&__get_cpu_var(irq_thermal_counts));
    >
    > The patch does atomic ops on cpu-local variables. This isn't needed, and
    > is expensive.
    >
    > If the field is only ever modified from hard interrupt context then you can
    > make the field unsigned long and use plain old `foo++'.
    >
    > If the field is modified from both hard-IRQ and from non-IRQ then use a
    > local_t and local_inc.
    >
    > Or even, given that this is just a statistic and grrat precision is not
    > needed, use unsigned long and f++ even if that _is_ racy. Because the
    > consequences of a race will just be a single lost count, which we dont'
    > care about enough to add the additional overhead of an atomic op.

    Hi Andrew,
    Thanks for the comments. I'll, at least, make the changes you suggested.

    (the /proc/interrupts version has the benefit of being smaller too).

    Joe

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