Re: [PATCH] 1-2-3 GB

[Andrew Morton]

Hugh Dickins wrote:
> ...
> The patch below seems to be enough to convince egcs-2.91.66 and
> gcc-2.95.3 to use a "jb" comparison there.
> ...
> -       for (j = 0; j < PTRS_PER_PMD ; j++) {
> -               prefetchw(pmd+j+(PREFETCH_STRIDE/16));
> -               free_one_pmd(pmd+j);
> +       for (md = pmd, emd = pmd + PTRS_PER_PMD; md < emd; md++) {
> +               prefetchw(md+(PREFETCH_STRIDE/16));
> +               free_one_pmd(md);

You need to add a big fat comment here, describing the compiler
problem, and the risks which attend any change to this code.

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