Re: [PATCH] avoid unnecessary cache flushes

Richard Henderson
2001-09-03T20:14:39Z

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~