Messages in this thread |  | | | Subject | Re: [PATCH] support for Cobalt Networks (x86 only) systems (for | | Date | Sat, 2 Jun 2001 17:15:02 +0100 (BST) | | From | Alan Cox <> |
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> > keeps beating it. You don't even need maliciousness for this, synchronization > > effects and locking on the file will ensure it gets you in the end > > Sure, but as I already wrote, you can detect that something is wrong. Then > shoot the person!
How does that solve the problem ?
> > fstat() mtime. That seems easy enough > > This only answered the first part of the question: when. How do you pass > the "how long" info ? > Does the same applies for the MII ioctl case ?
The mtime tells you exactly that.
> Caching means that the driver (I don't think that it can be done at > higher levels) has to keep track of accesses to all MII interfaces (yes, > there can be more than one on a NIC) and all of their registers. One
I disagree. A non priviledged app should not be able to poke around in MII registers anyway. So you only have to cache the generic state of the link.
> each MII register access. Another solution is to have each register start > its own cache timer.
You don't need timers.
> OTOH, ioctl rate limiting can be done at higher level and you need only > one timer per netdevice. So, it's done once and all net drivers benefit > from it.
You don't need any timers if you are caching. Zilch nada none. You know the last time a query came in. The mtime lets the app know the last time the value was modified.
Alan
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