[PATCH] Make NO_PTHREADS the sole thread configuration variable

[PATCH] Make NO_PTHREADS the sole thread configuration variable

[Dan McGee]

When the first piece of threaded code was introduced in commit 8ecce684, it
came with its own THREADED_DELTA_SEARCH Makefile option. Since this time,
more threaded code has come into the codebase and a NO_PTHREADS option has
also been added. Get rid of the original option as the newer, more generic
option covers everything we need.

Signed-off-by: Dan McGee <dpmcgee@gmail.com>
---
From looking over the way we use these two variables, it doesn't appear we
have any cases where the two of these were out of sync. If I missed
something, feel free to let me know. I did see some recent discussion
regarding msys and threaded-grep, but that didn't come into play here. It
did make me shudder seeing yet another THREADED_* option get suggested,
however.

-Dan

 Makefile               |   24 ++----------------------
 builtin-pack-objects.c |   12 ++++++------
 configure.ac           |    9 ++-------
 3 files changed, 10 insertions(+), 35 deletions(-)

diff --git a/Makefile b/Makefile
index af08c8f..83383c3 100644
--- a/Makefile
+++ b/Makefile
@@ -180,9 +180,6 @@ all::
 # If not set it defaults to the bare 'wish'. If it is set to the empty
 # string then NO_TCLTK will be forced (this is used by configure script).
 #
-# Define THREADED_DELTA_SEARCH if you have pthreads and wish to exploit
-# parallel delta searching when packing objects.
-#
 # Define INTERNAL_QSORT to use Git's implementation of qsort(), which
 # is a simplified version of the merge sort used in glibc. This is
 # recommended if Git triggers O(n^2) behavior in your platform's qsort().
@@ -722,12 +719,10 @@ EXTLIBS =
 ifeq ($(uname_S),Linux)
 	NO_STRLCPY = YesPlease
 	NO_MKSTEMPS = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),GNU/kFreeBSD)
 	NO_STRLCPY = YesPlease
 	NO_MKSTEMPS = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),UnixWare)
 	CC = cc
@@ -781,7 +776,6 @@ ifeq ($(uname_S),Darwin)
 		NO_STRLCPY = YesPlease
 	endif
 	NO_MEMMEM = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 	USE_ST_TIMESPEC = YesPlease
 endif
 ifeq ($(uname_S),SunOS)
@@ -794,7 +788,6 @@ ifeq ($(uname_S),SunOS)
 	NO_MKDTEMP = YesPlease
 	NO_MKSTEMPS = YesPlease
 	NO_REGEX = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 	ifeq ($(uname_R),5.7)
 		NEEDS_RESOLV = YesPlease
 		NO_IPV6 = YesPlease
@@ -850,7 +843,6 @@ ifeq ($(uname_S),FreeBSD)
 	BASIC_LDFLAGS += -L/usr/local/lib
 	DIR_HAS_BSD_GROUP_SEMANTICS = YesPlease
 	USE_ST_TIMESPEC = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 	ifeq ($(shell expr "$(uname_R)" : '4\.'),2)
 		PTHREAD_LIBS = -pthread
 		NO_UINTMAX_T = YesPlease
@@ -864,7 +856,6 @@ ifeq ($(uname_S),OpenBSD)
 	NEEDS_LIBICONV = YesPlease
 	BASIC_CFLAGS += -I/usr/local/include
 	BASIC_LDFLAGS += -L/usr/local/lib
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),NetBSD)
 	ifeq ($(shell expr "$(uname_R)" : '[01]\.'),2)
@@ -872,7 +863,6 @@ ifeq ($(uname_S),NetBSD)
 	endif
 	BASIC_CFLAGS += -I/usr/pkg/include
 	BASIC_LDFLAGS += -L/usr/pkg/lib $(CC_LD_DYNPATH)/usr/pkg/lib
-	THREADED_DELTA_SEARCH = YesPlease
 	USE_ST_TIMESPEC = YesPlease
 	NO_MKSTEMPS = YesPlease
 endif
@@ -887,9 +877,7 @@ ifeq ($(uname_S),AIX)
 	INTERNAL_QSORT = UnfortunatelyYes
 	NEEDS_LIBICONV=YesPlease
 	BASIC_CFLAGS += -D_LARGE_FILES
-	ifneq ($(shell expr "$(uname_V)" : '[1234]'),1)
-		THREADED_DELTA_SEARCH = YesPlease
-	else
+	ifeq ($(shell expr "$(uname_V)" : '[1234]'),1)
 		NO_PTHREADS = YesPlease
 	endif
 endif
@@ -915,7 +903,6 @@ ifeq ($(uname_S),IRIX)
 	SNPRINTF_RETURNS_BOGUS = YesPlease
 	SHELL_PATH = /usr/gnu/bin/bash
 	NEEDS_LIBGEN = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),IRIX64)
 	NO_SETENV=YesPlease
@@ -934,7 +921,6 @@ ifeq ($(uname_S),IRIX64)
 	SNPRINTF_RETURNS_BOGUS = YesPlease
 	SHELL_PATH=/usr/gnu/bin/bash
 	NEEDS_LIBGEN = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),HP-UX)
 	NO_IPV6=YesPlease
@@ -984,7 +970,6 @@ ifeq ($(uname_S),Windows)
 	NO_CURL = YesPlease
 	NO_PYTHON = YesPlease
 	BLK_SHA1 = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 
 	CC = compat/vcbuild/scripts/clink.pl
 	AR = compat/vcbuild/scripts/lib.pl
@@ -1036,7 +1021,6 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	NO_REGEX = YesPlease
 	NO_PYTHON = YesPlease
 	BLK_SHA1 = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 	COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat -Icompat/fnmatch -Icompat/win32
 	COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
 	COMPAT_OBJS += compat/mingw.o compat/fnmatch/fnmatch.o compat/winansi.o \
@@ -1334,16 +1318,12 @@ ifdef RUNTIME_PREFIX
 endif
 
 ifdef NO_PTHREADS
-	THREADED_DELTA_SEARCH =
 	BASIC_CFLAGS += -DNO_PTHREADS
 else
 	EXTLIBS += $(PTHREAD_LIBS)
-endif
-
-ifdef THREADED_DELTA_SEARCH
-	BASIC_CFLAGS += -DTHREADED_DELTA_SEARCH
 	LIB_OBJS += thread-utils.o
 endif
+
 ifdef DIR_HAS_BSD_GROUP_SEMANTICS
 	COMPAT_CFLAGS += -DDIR_HAS_BSD_GROUP_SEMANTICS
 endif
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index b0887d7..4a41547 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -17,7 +17,7 @@
 #include "progress.h"
 #include "refs.h"
 
-#ifdef THREADED_DELTA_SEARCH
+#ifndef NO_PTHREADS
 #include "thread-utils.h"
 #include <pthread.h>
 #endif
@@ -1255,7 +1255,7 @@ static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
 	return 0;
 }
 
-#ifdef THREADED_DELTA_SEARCH
+#ifndef NO_PTHREADS
 
 static pthread_mutex_t read_mutex;
 #define read_lock()		pthread_mutex_lock(&read_mutex)
@@ -1380,7 +1380,7 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
 	/*
 	 * Handle memory allocation outside of the cache
 	 * accounting lock.  Compiler will optimize the strangeness
-	 * away when THREADED_DELTA_SEARCH is not defined.
+	 * away when NO_PTHREADS is defined.
 	 */
 	free(trg_entry->delta_data);
 	cache_lock();
@@ -1567,7 +1567,7 @@ static void find_deltas(struct object_entry **list, unsigned *list_size,
 	free(array);
 }
 
-#ifdef THREADED_DELTA_SEARCH
+#ifndef NO_PTHREADS
 
 /*
  * The main thread waits on the condition that (at least) one of the workers
@@ -1899,7 +1899,7 @@ static int git_pack_config(const char *k, const char *v, void *cb)
 		if (delta_search_threads < 0)
 			die("invalid number of threads specified (%d)",
 			    delta_search_threads);
-#ifndef THREADED_DELTA_SEARCH
+#ifdef NO_PTHREADS
 		if (delta_search_threads != 1)
 			warning("no threads support, ignoring %s", k);
 #endif
@@ -2227,7 +2227,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			delta_search_threads = strtoul(arg+10, &end, 0);
 			if (!arg[10] || *end || delta_search_threads < 0)
 				usage(pack_usage);
-#ifndef THREADED_DELTA_SEARCH
+#ifdef NO_PTHREADS
 			if (delta_search_threads != 1)
 				warning("no threads support, "
 					"ignoring %s", arg);
diff --git a/configure.ac b/configure.ac
index 78345eb..229140e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -762,10 +762,9 @@ AC_SUBST(NO_MKSTEMPS)
 # Define NO_SYMLINK_HEAD if you never want .git/HEAD to be a symbolic link.
 # Enable it on Windows.  By default, symrefs are still used.
 #
-# Define NO_PTHREADS if we do not have pthreads
+# Define NO_PTHREADS if we do not have pthreads.
 #
-# Define PTHREAD_LIBS to the linker flag used for Pthread support and define
-# THREADED_DELTA_SEARCH if Pthreads are available.
+# Define PTHREAD_LIBS to the linker flag used for Pthread support.
 AC_DEFUN([PTHREADTEST_SRC], [
 #include <pthread.h>
 
@@ -782,7 +781,6 @@ dnl   [[pthread_mutex_t test_mutex;]]
 dnl )])
 
 NO_PTHREADS=UnfortunatelyYes
-THREADED_DELTA_SEARCH=
 PTHREAD_LIBS=
 
 if test -n "$USER_NOPTHREAD"; then
@@ -798,7 +796,6 @@ elif test -z "$PTHREAD_CFLAGS"; then
 	[AC_MSG_RESULT([yes])
 		NO_PTHREADS=
 		PTHREAD_LIBS="$opt"
-		THREADED_DELTA_SEARCH=YesPlease
 		break
 	],
 	[AC_MSG_RESULT([no])])
@@ -812,7 +809,6 @@ else
 	[AC_MSG_RESULT([yes])
 		NO_PTHREADS=
 		PTHREAD_LIBS="$PTHREAD_CFLAGS"
-		THREADED_DELTA_SEARCH=YesPlease
 	],
 	[AC_MSG_RESULT([no])])
 
@@ -823,7 +819,6 @@ CFLAGS="$old_CFLAGS"
 
 AC_SUBST(PTHREAD_LIBS)
 AC_SUBST(NO_PTHREADS)
-AC_SUBST(THREADED_DELTA_SEARCH)
 
 ## Output files
 AC_CONFIG_FILES(["${config_file}":"${config_in}":"${config_append}"])
-- 
1.6.6.1

Re: [PATCH] Make NO_PTHREADS the sole thread configuration variable

[Junio C Hamano]

Dan McGee <dpmcgee@gmail.com> writes:

> When the first piece of threaded code was introduced in commit 8ecce684, it
> came with its own THREADED_DELTA_SEARCH Makefile option. Since this time,
> more threaded code has come into the codebase and a NO_PTHREADS option has
> also been added. Get rid of the original option as the newer, more generic
> option covers everything we need.

The patch is a good change but only in the "if it were like this from day
one, things would have been much simpler" sense.  It is a breakage to
existing users with customized THREADED_DELTA_SEARCH in their config.mak
files, isn't it?

If we take only the part of your patch that applies to Makefile, but
exclude the first hunk (description of THREADED_DELTA_SEARCH) and the last
hunk (the necessary part to keep THREADED_DELTA_SEARCH working), and
instead add something like:

	ifndef NO_PTHREADS
        	THREADED_DELTA_SEARCH = YesPlease
	endif

immediately before we include config.mak, would that be a workable
solution to:

 (1) keep existing users happy;

 (2) remove the redundant logic to compute the default for two Make
     variables; and

 (3) keep control over use of threading in general _and_ use of
     threading in delta computation?

Re: [PATCH] Make NO_PTHREADS the sole thread configuration variable

[Nicolas Pitre]

On Sat, 30 Jan 2010, Junio C Hamano wrote:

> Dan McGee <dpmcgee@gmail.com> writes:
> 
> > When the first piece of threaded code was introduced in commit 8ecce684, it
> > came with its own THREADED_DELTA_SEARCH Makefile option. Since this time,
> > more threaded code has come into the codebase and a NO_PTHREADS option has
> > also been added. Get rid of the original option as the newer, more generic
> > option covers everything we need.
> 
> The patch is a good change but only in the "if it were like this from day
> one, things would have been much simpler" sense.  It is a breakage to
> existing users with customized THREADED_DELTA_SEARCH in their config.mak
> files, isn't it?

I think that the release of v1.7.0 is the perfect match for such a 
"breakage".  Unlike for the dashless move, I really doubt the majority 
of Git users are using a customized THREADED_DELTA_SEARCH in a 
config.mak if they do build Git themselves at all.  So very few people 
are likely to be inconvenienced, and yet the inconvenience can hardly be 
qualified as a breakage since nothing will stop working in any case.

> If we take only the part of your patch that applies to Makefile, but
> exclude the first hunk (description of THREADED_DELTA_SEARCH) and the last
> hunk (the necessary part to keep THREADED_DELTA_SEARCH working), and
> instead add something like:
> 
> 	ifndef NO_PTHREADS
>         	THREADED_DELTA_SEARCH = YesPlease
> 	endif
> 
> immediately before we include config.mak, would that be a workable
> solution to:
> 
>  (1) keep existing users happy;
> 
>  (2) remove the redundant logic to compute the default for two Make
>      variables; and
> 
>  (3) keep control over use of threading in general _and_ use of
>      threading in delta computation?

IMHO I wouldn't bother that much.  Simply mentioning in the 1.7.0 
release notes that THREADED_DELTA_SEARCH is no more should be fine.  
Like I said, the existing users who might be affected are certainly few, 
and the impact on them is rather trivial.


Nicolas

Re: [PATCH] Make NO_PTHREADS the sole thread configuration variable

[Dan McGee]

On Sat, Jan 30, 2010 at 7:29 PM, Nicolas Pitre <nico@fluxnic.net> wrote:
> On Sat, 30 Jan 2010, Junio C Hamano wrote:
>
>> Dan McGee <dpmcgee@gmail.com> writes:
>>
>> > When the first piece of threaded code was introduced in commit 8ecce684, it
>> > came with its own THREADED_DELTA_SEARCH Makefile option. Since this time,
>> > more threaded code has come into the codebase and a NO_PTHREADS option has
>> > also been added. Get rid of the original option as the newer, more generic
>> > option covers everything we need.
>>
>> The patch is a good change but only in the "if it were like this from day
>> one, things would have been much simpler" sense.  It is a breakage to
>> existing users with customized THREADED_DELTA_SEARCH in their config.mak
>> files, isn't it?
>
> I think that the release of v1.7.0 is the perfect match for such a
> "breakage".  Unlike for the dashless move, I really doubt the majority
> of Git users are using a customized THREADED_DELTA_SEARCH in a
> config.mak if they do build Git themselves at all.  So very few people
> are likely to be inconvenienced, and yet the inconvenience can hardly be
> qualified as a breakage since nothing will stop working in any case.
>
>> If we take only the part of your patch that applies to Makefile, but
>> exclude the first hunk (description of THREADED_DELTA_SEARCH) and the last
>> hunk (the necessary part to keep THREADED_DELTA_SEARCH working), and
>> instead add something like:
>>
>>       ifndef NO_PTHREADS
>>               THREADED_DELTA_SEARCH = YesPlease
>>       endif
>>
>> immediately before we include config.mak, would that be a workable
>> solution to:
>>
>>  (1) keep existing users happy;
>>
>>  (2) remove the redundant logic to compute the default for two Make
>>      variables; and
>>
>>  (3) keep control over use of threading in general _and_ use of
>>      threading in delta computation?
>
> IMHO I wouldn't bother that much.  Simply mentioning in the 1.7.0
> release notes that THREADED_DELTA_SEARCH is no more should be fine.
> Like I said, the existing users who might be affected are certainly few,
> and the impact on them is rather trivial.

This is everything I wanted to say as well. I just don't think this is
that big of a deal to "break compatibility" as I can think of no
reason why you would only want 2/3 of the pthreads code enabled (your
point 3). What this does do is set the precedent for any future
threads code to only use NO_PTHREADS and not introduce yet another
preprocessor define.

If this gets applied, it needs a small correction- I can resubmit, but
the only difference is this:

diff --git a/config.mak.in b/config.mak.in
index 67b12f7..6008ac9 100644
--- a/config.mak.in
+++ b/config.mak.in
@@ -56,5 +56,4 @@ NO_DEFLATE_BOUND=@NO_DEFLATE_BOUND@
 FREAD_READS_DIRECTORIES=@FREAD_READS_DIRECTORIES@
 SNPRINTF_RETURNS_BOGUS=@SNPRINTF_RETURNS_BOGUS@
 NO_PTHREADS=@NO_PTHREADS@
-THREADED_DELTA_SEARCH=@THREADED_DELTA_SEARCH@
 PTHREAD_LIBS=@PTHREAD_LIBS@


-Dan

Re: [PATCH] Make NO_PTHREADS the sole thread configuration variable

[Junio C Hamano]

Nicolas Pitre <nico@fluxnic.net> writes:

> Simply mentioning in the 1.7.0 
> release notes that THREADED_DELTA_SEARCH is no more should be fine.  

Ok; here is what I'll queue.

Thanks, both.

-- >8 --
From: Dan McGee <dpmcgee@gmail.com>
Date: Fri, 29 Jan 2010 19:22:19 -0600
Subject: [PATCH] Make NO_PTHREADS the sole thread configuration variable

When the first piece of threaded code was introduced in commit 8ecce684, it
came with its own THREADED_DELTA_SEARCH Makefile option. Since this time,
more threaded code has come into the codebase and a NO_PTHREADS option has
also been added. Get rid of the original option as the newer, more generic
option covers everything we need.

Signed-off-by: Dan McGee <dpmcgee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/RelNotes-1.7.0.txt |    3 +++
 Makefile                         |   24 ++----------------------
 builtin-pack-objects.c           |   12 ++++++------
 config.mak.in                    |    1 -
 configure.ac                     |    9 ++-------
 5 files changed, 13 insertions(+), 36 deletions(-)

diff --git a/Documentation/RelNotes-1.7.0.txt b/Documentation/RelNotes-1.7.0.txt
index 997b026..45ac906 100644
--- a/Documentation/RelNotes-1.7.0.txt
+++ b/Documentation/RelNotes-1.7.0.txt
@@ -175,6 +175,9 @@ Updates since v1.6.6
 
  * Many more commands are now built-in.
 
+ * THREADED_DELTA_SEARCH is no more.  If you build with threads, delta
+   compression will always take advantage of it.
+
 Fixes since v1.6.6
 ------------------
 
diff --git a/Makefile b/Makefile
index af08c8f..83383c3 100644
--- a/Makefile
+++ b/Makefile
@@ -180,9 +180,6 @@ all::
 # If not set it defaults to the bare 'wish'. If it is set to the empty
 # string then NO_TCLTK will be forced (this is used by configure script).
 #
-# Define THREADED_DELTA_SEARCH if you have pthreads and wish to exploit
-# parallel delta searching when packing objects.
-#
 # Define INTERNAL_QSORT to use Git's implementation of qsort(), which
 # is a simplified version of the merge sort used in glibc. This is
 # recommended if Git triggers O(n^2) behavior in your platform's qsort().
@@ -722,12 +719,10 @@ EXTLIBS =
 ifeq ($(uname_S),Linux)
 	NO_STRLCPY = YesPlease
 	NO_MKSTEMPS = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),GNU/kFreeBSD)
 	NO_STRLCPY = YesPlease
 	NO_MKSTEMPS = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),UnixWare)
 	CC = cc
@@ -781,7 +776,6 @@ ifeq ($(uname_S),Darwin)
 		NO_STRLCPY = YesPlease
 	endif
 	NO_MEMMEM = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 	USE_ST_TIMESPEC = YesPlease
 endif
 ifeq ($(uname_S),SunOS)
@@ -794,7 +788,6 @@ ifeq ($(uname_S),SunOS)
 	NO_MKDTEMP = YesPlease
 	NO_MKSTEMPS = YesPlease
 	NO_REGEX = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 	ifeq ($(uname_R),5.7)
 		NEEDS_RESOLV = YesPlease
 		NO_IPV6 = YesPlease
@@ -850,7 +843,6 @@ ifeq ($(uname_S),FreeBSD)
 	BASIC_LDFLAGS += -L/usr/local/lib
 	DIR_HAS_BSD_GROUP_SEMANTICS = YesPlease
 	USE_ST_TIMESPEC = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 	ifeq ($(shell expr "$(uname_R)" : '4\.'),2)
 		PTHREAD_LIBS = -pthread
 		NO_UINTMAX_T = YesPlease
@@ -864,7 +856,6 @@ ifeq ($(uname_S),OpenBSD)
 	NEEDS_LIBICONV = YesPlease
 	BASIC_CFLAGS += -I/usr/local/include
 	BASIC_LDFLAGS += -L/usr/local/lib
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),NetBSD)
 	ifeq ($(shell expr "$(uname_R)" : '[01]\.'),2)
@@ -872,7 +863,6 @@ ifeq ($(uname_S),NetBSD)
 	endif
 	BASIC_CFLAGS += -I/usr/pkg/include
 	BASIC_LDFLAGS += -L/usr/pkg/lib $(CC_LD_DYNPATH)/usr/pkg/lib
-	THREADED_DELTA_SEARCH = YesPlease
 	USE_ST_TIMESPEC = YesPlease
 	NO_MKSTEMPS = YesPlease
 endif
@@ -887,9 +877,7 @@ ifeq ($(uname_S),AIX)
 	INTERNAL_QSORT = UnfortunatelyYes
 	NEEDS_LIBICONV=YesPlease
 	BASIC_CFLAGS += -D_LARGE_FILES
-	ifneq ($(shell expr "$(uname_V)" : '[1234]'),1)
-		THREADED_DELTA_SEARCH = YesPlease
-	else
+	ifeq ($(shell expr "$(uname_V)" : '[1234]'),1)
 		NO_PTHREADS = YesPlease
 	endif
 endif
@@ -915,7 +903,6 @@ ifeq ($(uname_S),IRIX)
 	SNPRINTF_RETURNS_BOGUS = YesPlease
 	SHELL_PATH = /usr/gnu/bin/bash
 	NEEDS_LIBGEN = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),IRIX64)
 	NO_SETENV=YesPlease
@@ -934,7 +921,6 @@ ifeq ($(uname_S),IRIX64)
 	SNPRINTF_RETURNS_BOGUS = YesPlease
 	SHELL_PATH=/usr/gnu/bin/bash
 	NEEDS_LIBGEN = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 endif
 ifeq ($(uname_S),HP-UX)
 	NO_IPV6=YesPlease
@@ -984,7 +970,6 @@ ifeq ($(uname_S),Windows)
 	NO_CURL = YesPlease
 	NO_PYTHON = YesPlease
 	BLK_SHA1 = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 
 	CC = compat/vcbuild/scripts/clink.pl
 	AR = compat/vcbuild/scripts/lib.pl
@@ -1036,7 +1021,6 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	NO_REGEX = YesPlease
 	NO_PYTHON = YesPlease
 	BLK_SHA1 = YesPlease
-	THREADED_DELTA_SEARCH = YesPlease
 	COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat -Icompat/fnmatch -Icompat/win32
 	COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
 	COMPAT_OBJS += compat/mingw.o compat/fnmatch/fnmatch.o compat/winansi.o \
@@ -1334,16 +1318,12 @@ ifdef RUNTIME_PREFIX
 endif
 
 ifdef NO_PTHREADS
-	THREADED_DELTA_SEARCH =
 	BASIC_CFLAGS += -DNO_PTHREADS
 else
 	EXTLIBS += $(PTHREAD_LIBS)
-endif
-
-ifdef THREADED_DELTA_SEARCH
-	BASIC_CFLAGS += -DTHREADED_DELTA_SEARCH
 	LIB_OBJS += thread-utils.o
 endif
+
 ifdef DIR_HAS_BSD_GROUP_SEMANTICS
 	COMPAT_CFLAGS += -DDIR_HAS_BSD_GROUP_SEMANTICS
 endif
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c
index b0887d7..4a41547 100644
--- a/builtin-pack-objects.c
+++ b/builtin-pack-objects.c
@@ -17,7 +17,7 @@
 #include "progress.h"
 #include "refs.h"
 
-#ifdef THREADED_DELTA_SEARCH
+#ifndef NO_PTHREADS
 #include "thread-utils.h"
 #include <pthread.h>
 #endif
@@ -1255,7 +1255,7 @@ static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
 	return 0;
 }
 
-#ifdef THREADED_DELTA_SEARCH
+#ifndef NO_PTHREADS
 
 static pthread_mutex_t read_mutex;
 #define read_lock()		pthread_mutex_lock(&read_mutex)
@@ -1380,7 +1380,7 @@ static int try_delta(struct unpacked *trg, struct unpacked *src,
 	/*
 	 * Handle memory allocation outside of the cache
 	 * accounting lock.  Compiler will optimize the strangeness
-	 * away when THREADED_DELTA_SEARCH is not defined.
+	 * away when NO_PTHREADS is defined.
 	 */
 	free(trg_entry->delta_data);
 	cache_lock();
@@ -1567,7 +1567,7 @@ static void find_deltas(struct object_entry **list, unsigned *list_size,
 	free(array);
 }
 
-#ifdef THREADED_DELTA_SEARCH
+#ifndef NO_PTHREADS
 
 /*
  * The main thread waits on the condition that (at least) one of the workers
@@ -1899,7 +1899,7 @@ static int git_pack_config(const char *k, const char *v, void *cb)
 		if (delta_search_threads < 0)
 			die("invalid number of threads specified (%d)",
 			    delta_search_threads);
-#ifndef THREADED_DELTA_SEARCH
+#ifdef NO_PTHREADS
 		if (delta_search_threads != 1)
 			warning("no threads support, ignoring %s", k);
 #endif
@@ -2227,7 +2227,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			delta_search_threads = strtoul(arg+10, &end, 0);
 			if (!arg[10] || *end || delta_search_threads < 0)
 				usage(pack_usage);
-#ifndef THREADED_DELTA_SEARCH
+#ifdef NO_PTHREADS
 			if (delta_search_threads != 1)
 				warning("no threads support, "
 					"ignoring %s", arg);
diff --git a/config.mak.in b/config.mak.in
index 67b12f7..6008ac9 100644
--- a/config.mak.in
+++ b/config.mak.in
@@ -56,5 +56,4 @@ NO_DEFLATE_BOUND=@NO_DEFLATE_BOUND@
 FREAD_READS_DIRECTORIES=@FREAD_READS_DIRECTORIES@
 SNPRINTF_RETURNS_BOGUS=@SNPRINTF_RETURNS_BOGUS@
 NO_PTHREADS=@NO_PTHREADS@
-THREADED_DELTA_SEARCH=@THREADED_DELTA_SEARCH@
 PTHREAD_LIBS=@PTHREAD_LIBS@
diff --git a/configure.ac b/configure.ac
index 78345eb..229140e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -762,10 +762,9 @@ AC_SUBST(NO_MKSTEMPS)
 # Define NO_SYMLINK_HEAD if you never want .git/HEAD to be a symbolic link.
 # Enable it on Windows.  By default, symrefs are still used.
 #
-# Define NO_PTHREADS if we do not have pthreads
+# Define NO_PTHREADS if we do not have pthreads.
 #
-# Define PTHREAD_LIBS to the linker flag used for Pthread support and define
-# THREADED_DELTA_SEARCH if Pthreads are available.
+# Define PTHREAD_LIBS to the linker flag used for Pthread support.
 AC_DEFUN([PTHREADTEST_SRC], [
 #include <pthread.h>
 
@@ -782,7 +781,6 @@ dnl   [[pthread_mutex_t test_mutex;]]
 dnl )])
 
 NO_PTHREADS=UnfortunatelyYes
-THREADED_DELTA_SEARCH=
 PTHREAD_LIBS=
 
 if test -n "$USER_NOPTHREAD"; then
@@ -798,7 +796,6 @@ elif test -z "$PTHREAD_CFLAGS"; then
 	[AC_MSG_RESULT([yes])
 		NO_PTHREADS=
 		PTHREAD_LIBS="$opt"
-		THREADED_DELTA_SEARCH=YesPlease
 		break
 	],
 	[AC_MSG_RESULT([no])])
@@ -812,7 +809,6 @@ else
 	[AC_MSG_RESULT([yes])
 		NO_PTHREADS=
 		PTHREAD_LIBS="$PTHREAD_CFLAGS"
-		THREADED_DELTA_SEARCH=YesPlease
 	],
 	[AC_MSG_RESULT([no])])
 
@@ -823,7 +819,6 @@ CFLAGS="$old_CFLAGS"
 
 AC_SUBST(PTHREAD_LIBS)
 AC_SUBST(NO_PTHREADS)
-AC_SUBST(THREADED_DELTA_SEARCH)
 
 ## Output files
 AC_CONFIG_FILES(["${config_file}":"${config_in}":"${config_append}"])
-- 
1.7.0.rc1.141.gd3fd2