uml: speed page fault path
Give the page fault code a specialized path. There is only one page to look
at, so there's no point in going into the general page table walking code.
There's only going to be one host operation, so there are no opportunities for
merging. So, we go straight to the pte we want, figure out what needs doing,
and do it.
While I was in here, I fixed the wart where the address passed to unmap was a
void *, but an unsigned long to map and protect.
This gives me just under 10% on a kernel build.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index d663809..e11bdcd 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -302,7 +302,7 @@
extern int map(struct mm_id * mm_idp, unsigned long virt,
unsigned long len, int r, int w, int x, int phys_fd,
unsigned long long offset, int done, void **data);
-extern int unmap(struct mm_id * mm_idp, void *addr, unsigned long len,
+extern int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
int done, void **data);
extern int protect(struct mm_id * mm_idp, unsigned long addr,
unsigned long len, int r, int w, int x, int done,