Re: [RFC] [PATCH] cache pollution aware __copy_from_user_ll()

From: Christoph Hellwig
Date: Sun Aug 14 2005 - 05:45:59 EST


> the problem is that the pay elsewhere is far more spread out, but not
> less. At least generally....
>
> I can see the point of a copy_from_user_nocache() or something, for
> those cases where we *know* we are not going to use the copied data in
> the cpu (but say, only do DMA).
> But that should be explicit, not implicit, since the general case will
> be that the kernel WILL use the data.

Most of the callers probably want the normal one, but most of the copied
data (buffered filesystem I/O) will want the non cache poluting one.

So yes, doing this explicit makes a lot of sense.

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