Messages in this thread | | | Date | Wed, 2 Jul 2008 19:35:11 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH 1/2] Introduce copy_user_handle_tail routine |
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On Wed, 2 Jul 2008, Vitaly Mayatskikh wrote: > > Linus wanted this routine to be extremely dumb.
Well, I wanted it simple and dumb, but not dumber than _necessary_.
I think
if (cleartail) memset(dst,0,len); return len;
is basically what we should have at the end. Simple and sweet.
Now, the stuff that comes *before* that point is the "try to fix up one byte at a time" thing, which I'd like to be simple and dumb. At least to start with.
Of course, I also suspect that *eventually* we might want to make it smarter and more complex. For example, while performance isn't a primary issue, we might want to eventually avoid having to do _two_ faults (once in the fast unrolled or word-at-a-time loop, and once in the byte-for-byte one), by limiting the byte-for-byte one to be within a page, but that would be a "future enhancement" thing.
Linus
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