Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ce7e9fae8db07af4080e868f4588f8f095f803dc
Commit: ce7e9fae8db07af4080e868f4588f8f095f803dc
Parent: b8e7a54cd06b0b0174029ef3a7f5a1415a2c28f2
Author: Christian Borntraeger <[EMAIL PROTECTED]>
AuthorDate: Tue Nov 20 11:13:36 2007 +0100
Committer: Martin Schwidefsky <[EMAIL PROTECTED]>
CommitDate: Tue Nov 20 11:13:46 2007 +0100
[S390] Optimize storage key handling for anonymous pages
page_mkclean used to call page_clear_dirty for every given page. This
is different to all other architectures, where the dirty bit in the
PTEs is only resetted, if page_mapping() returns a non-NULL pointer.
We can move the page_test_dirty/page_clear_dirty sequence into the
2nd if to avoid unnecessary iske/sske sequences, which are expensive.
This change also helps kvm for s390 as the host must transfer the
dirty bit into the guest status bits. By moving the page_clear_dirty
operation into the 2nd if, the vm will only call page_clear_dirty
for pages where it walks the mapping anyway. There it calls
ptep_clear_flush for writable ptes, so we can transfer the dirty bit
to the guest.
Signed-off-by: Christian Borntraeger <[EMAIL PROTECTED]>
Signed-off-by: Martin Schwidefsky <[EMAIL PROTECTED]>
---
mm/rmap.c | 9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index dc3be5f..dbc2ca2 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -471,11 +471,12 @@ int page_mkclean(struct page *page)
if (page_mapped(page)) {
struct address_space *mapping = page_mapping(page);
- if (mapping)
+ if (mapping) {
ret = page_mkclean_file(mapping, page);
- if (page_test_dirty(page)) {
- page_clear_dirty(page);
- ret = 1;
+ if (page_test_dirty(page)) {
+ page_clear_dirty(page);
+ ret = 1;
+ }
}
}
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
