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    SubjectRe: Is sysfs the right place to get cache and CPU topology info?
    Andi Kleen wrote:
    > Andrew Morton <> writes:
    > >
    > > sysfs is part of the kernel ABI. We should design our interfaces there
    > > as carefully as we design any others.
    > The basic problem is that sysfs exports an internal kernel object model
    > and these tend to change. To really make it stable would require
    > splitting it into internal and presented interface.

    True, but... /sys/devices/system/cpu has been there since around 2.6.5
    iirc. A google code search for that path shows plenty of programs
    (including hal) that hard-code it. Exposed object model or not,
    changing that path would break lots of software.

    > I would be all
    > for it, but it doesn't seem realistic to me currently. If we cannot
    > even get basic interfaces like the syscall capability stable how would
    > you expect to stabilize the complete kobjects?
    > And the specific problem with the x86 cache sysfs interface is that it's so
    > complicated that no human can really read it directly. This means to
    > actually use it you need some kind of frontend (i have a cheesy
    > lscache script for this).

    Human readability is nice, but a more important issue IMO is whether
    the cache interface can be considered stable enough for programs to
    rely on it. I notice there's no entry for it in Documentation/ABI.

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      Last update: 2008-07-02 16:39    [W:0.020 / U:16.052 seconds]
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