Messages in this thread |  | | | Date | Wed, 2 Jul 2008 09:35:54 -0500 | | From | Nathan Lynch <> | | Subject | Re: Is sysfs the right place to get cache and CPU topology info? |
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Andi Kleen wrote: > Andrew Morton <akpm@linux-foundation.org> 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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