Re: [PATCH] 1-2-3 GB

[Pavel Machek <pavel@suse.cz>]

Hi!

> The patch below seems to be enough to convince egcs-2.91.66 and
> gcc-2.95.3 to use a "jb" comparison there.  I'm working on PIII,
> prefetchw() just a stub, if that makes any difference.

If this is really gcc bug, would simply making j volatile fix it?

								Pavel
> --- 2.4.18pre2aa2/mm/memory.c	Sat Jan 12 18:01:36 2002
> +++ linux/mm/memory.c	Sat Jan 12 18:09:27 2002
> @@ -106,8 +106,7 @@
>  
>  static inline void free_one_pgd(pgd_t * dir)
>  {
> -	int j;
> -	pmd_t * pmd;
> +	pmd_t * pmd, * md, * emd;
>  
>  	if (pgd_none(*dir))
>  		return;
> @@ -118,9 +117,9 @@
>  	}
>  	pmd = pmd_offset(dir, 0);
>  	pgd_clear(dir);
> -	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);
>  	}
>  	pmd_free(pmd);
>  }

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