From 779a2514a61d103a9a1479478ad15d2ca9478d6c Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Wed, 10 Dec 2014 01:53:10 +0100
Subject: Hurd: Fix definition of `PAGE_COPY_THRESHOLD'

---
 .topdeps                |  2 +-
 .topmsg                 | 30 +++++++++++++++++++-----------
 sysdeps/mach/pagecopy.h |  2 +-
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/.topdeps b/.topdeps
index e7a14c6ca9..180b47c18b 100644
--- a/.topdeps
+++ b/.topdeps
@@ -1 +1 @@
-0323d08657f111267efa47bd448fbf6cd76befe8
+baseline
diff --git a/.topmsg b/.topmsg
index dd6634c886..a68dd006b9 100644
--- a/.topmsg
+++ b/.topmsg
@@ -1,16 +1,24 @@
-Subject: Baseline for our topic branches.
+From: Justus Winter <4winter@informatik.uni-hamburg.de>
+Subject: [PATCH] Hurd: Fix definition of `PAGE_COPY_THRESHOLD'
 
----
-
-This need not strictly be a TopGit branch, but it is for easy synchronization
-between different machines.
+Previously, `PAGE_THRESHOLD' was defined instead of
+`PAGE_COPY_THRESHOLD', preventing the optimization of memory copy
+operations using `vm_copy'.
 
-As the baseline is merged into the topic branches, it is forward-only.
+Also, increase the threshold to 4 pages.  XXX Tune this.
 
-To advance it:
-
-    $ echo [SHA1] > .topdeps
-    $ git commit -m Advance. -- .topdeps
-    $ tg update
+* sysdeps/mach/pagecopy.h (PAGE_THRESHOLD): Rename to `PAGE_COPY_THRESHOLD'.
+Raise threshold to XXX pages.
 
 ---
+This is however still WIP:
+
+“
+this currently doesn't make any difference since the
+Makefile rules end up compiling sysdeps/i386/i586/memcpy{,_chk}.S,
+i386/i586/memcopy.h, i386/memcopy.h instead...  Also, #if
+PAGE_COPY_THRESHOLD doesn't like PAGE_COPY_THRESHOLD being
+2*__vm_page_size, it ends up considering it false. Also, the rtld magic
+in elf/ doesn't manage to determine that it also needs to include
+wordcopy.os.
+”
diff --git a/sysdeps/mach/pagecopy.h b/sysdeps/mach/pagecopy.h
index 0a9f39d1bb..4dd1a39199 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		(16384)	/* XXX Tune this.  */
 
 #define PAGE_SIZE		__vm_page_size
 #define PAGE_COPY_FWD(dstp, srcp, nbytes_left, nbytes)			      \
-- 
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