Re: [PATCH] avoid unnecessary cache flushes

From: Richard Henderson (rth@twiddle.net)
Date: Mon Sep 03 2001 - 15:14:36 EST


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~
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Fri Sep 07 2001 - 21:00:20 EST