Re: optimizing fs/select.c for n==0

From: Chris Wedgwood (cw@f00f.org)
Date: Fri Mar 31 2000 - 03:13:43 EST


> In fs/select.c version 2.2.14 there is a comment in sys_select...

> /*
> * We ought to optimise the n=0 case - it is used enough..
> */
>
> if (n < 0)
> goto out_nofds;

> but this comment is gone in 2.3.99pre2. would this no longer be
> a useful optimization?

Only the comment is gone -- the code is still there. I'm not sure it
is a useful optimization, and anyhow, I think it really should be:

        if(n <= 0)
                goto out_nofds;

because you pass x+1 to select where x is your highest fd you want to
test for... (or n<1, whichever you prefer).

-cw

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