[lkml]   [2001]   [Sep]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] avoid unnecessary cache flushes
>>>>> On Mon, 3 Sep 2001 13:14:36 -0700, Richard Henderson <> said:

Richard> 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);

Richard> Race. Use test_and_set_bit.

Nope, the old code is correct: you must turn on PG_arch_1 *after*
flushing the cache. Yes, you might sometimes double flush, but that's
both safe and rare.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:02    [W:0.147 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site