Re: [PATCH] avoid unnecessary cache flushes

[Richard Henderson]

On Fri, Aug 31, 2001 at 09:18:50PM +1000, Paul Mackerras wrote:
> +		if (!test_bit(PG_arch_1, &page->flags)) {
> +			__flush_dcache_icache((unsigned long)kmap(page));
> +			kunmap(page);
> +			set_bit(PG_arch_1, &page->flags);

Race.  Use test_and_set_bit.

As for Alpha, all we have is "flush entire icache", so there's not
much interesting we can do by way of optimization I don't think.

r~