[PATCH glibc] Hurd: Fix definition of `PAGE_COPY_THRESHOLD'

[Justus Winter]

Previously, `PAGE_THRESHOLD' was defined instead of
`PAGE_COPY_THRESHOLD', preventing the optimization of memory copy
operations using `vm_copy'.

Also, increase the threshold to 4 pages.  XXX Tune this.

* sysdeps/mach/pagecopy.h (PAGE_THRESHOLD): Rename to `PAGE_COPY_THRESHOLD'.
Raise threshold to XXX pages.
---
 sysdeps/mach/pagecopy.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sysdeps/mach/pagecopy.h b/sysdeps/mach/pagecopy.h
index 8db2147..75e700a 100644
--- a/sysdeps/mach/pagecopy.h
+++ b/sysdeps/mach/pagecopy.h
@@ -20,7 +20,7 @@
 
 /* Threshold at which vm_copy is more efficient than well-optimized copying
    by words.  This parameter should be tuned as necessary.  */
-#define PAGE_THRESHOLD         (2 * PAGE_SIZE) /* XXX ? */
+#define PAGE_COPY_THRESHOLD    (4 * PAGE_SIZE) /* XXX Tune this.  */
 
 #define PAGE_SIZE              __vm_page_size
 #define PAGE_COPY_FWD(dstp, srcp, nbytes_left, nbytes)                       \
-- 
2.1.3