tree 2eb89d89a22380298d64edad59010c1d0a59e5a4
parent 2fc2d1e9ffcde78af7ab63ed640d9a4901797de2
author Martin Schwidefsky <schwidefsky@de.ibm.com> 1177682517 +0200
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1177682506 +0200

[S390] split page_test_and_clear_dirty.

The page_test_and_clear_dirty primitive really consists of two
operations, page_test_dirty and the page_clear_dirty. The combination
of the two is not an atomic operation, so it makes more sense to have
two separate operations instead of one.
In addition to the improved readability of the s390 version of
SetPageUptodate, it now avoids the page_test_dirty operation which is
an insert-storage-key-extended (iske) instruction which is an expensive
operation.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>