Page-cache Lock patch

Hello,

To prevent extensive locking after content refresh, I am trying to implement Page-cache Lock patch and this obviously needs Page-cache-memcache Lock patch to be translated to Cache's cache.inc include.

Then I changed this:

$cache->flush('cache_block');
$cache->flush('cache_page');

to this:

$cache->flush('cache_block');
//$cache->flush('cache_page');
// Special handling for the page cache.  Rather than flushing this table,
// we update a variable.  When pages are in high demand, this allows us to
// serve the old cached version while an updated version is being created.
variable_set('cache_page_clear', time());

manually on line 169.

Is this sane anyway? And/or is anything needed for memcache* includes under ./engines?

Thanks in advance.