From d8b57549d50ec4ffed51ac6dcc1e80a06c69e3f3 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Wed, 1 Jul 2015 20:46:00 +0200
Subject: [PATCH 217/217] configure: Add support for tcmalloc

Message-id: <1435783560-22369-1-git-send-email-pbonzini@redhat.com>
Patchwork-id: 66599
O-Subject: [RHEL7.2 qemu-kvm-rhev PATCH v2] configure: Add support for tcmalloc
Bugzilla: 1213882
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
RH-Acked-by: Juan Quintela <quintela@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

From: Fam Zheng <famz@redhat.com>

Bugzilla: 1213882

Brew build:
	http://brewweb.devel.redhat.com/brew/taskinfo?taskID=9451417 (qemu-ga)
	http://brewweb.devel.redhat.com/brew/taskinfo?taskID=9451418 (qemu-kvm-rhev)

This adds "--enable-tcmalloc" and "--disable-tcmalloc" to allow linking
to libtcmalloc from gperftools.

tcmalloc is a malloc implementation that works well with threads and is
fast, so it is good for performance.

It is disabled by default, because the MALLOC_PERTURB_ flag we use in
tests doesn't work with tcmalloc. However we can enable tcmalloc
specific heap checker and profilers later.

An IOPS gain can be observed with virtio-blk-dataplane, other parts of
QEMU will directly benefit from it as well:

==========================================================
                       glibc malloc
----------------------------------------------------------
rw         bs         iodepth    bw     iops       latency
read       4k         1          150    38511      24
----------------------------------------------------------

==========================================================
                         tcmalloc
----------------------------------------------------------
rw         bs         iodepth    bw     iops       latency
read       4k         1          156    39969      23
----------------------------------------------------------

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <1427338992-27057-1-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 2847b46958ab0bd604e1b3fcafba0f5ba4375833)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

Conflicts:
	configure

Note on the RHEL7 part:
	malloc(1) would fail to compile due to -D_FORTIFY_SOURCE=2 that
	configure passes in --extra-cflags.  The flag enables warnings
        for unused result of malloc.  However, QEMU already knows about
        -D_FORTIFY_SOURCE and enables it after configure tests are run.
	So, remove it from --extra-cflags and trust configure to do the
	right thing.

	The have_ flags are a bit messy.
---
 configure                             | 24 ++++++++++++++++++++++++
 redhat/build_configure.sh             |  3 +++
 redhat/qemu-guest-agent.spec.template | 13 +++++++++++++
 redhat/qemu-kvm.spec.template         | 15 +++++++++++++++
 4 files changed, 55 insertions(+)
---
 configure                             | 24 ++++++++++++++++++++++++
 redhat/build_configure.sh             |  3 +++
 redhat/qemu-guest-agent.spec.template | 13 +++++++++++++
 redhat/qemu-kvm.spec.template         | 15 +++++++++++++++
 4 files changed, 55 insertions(+)

diff --git a/configure b/configure
index f054934..280a1c2 100755
--- a/configure
+++ b/configure
@@ -337,6 +337,7 @@ vhdx=""
 quorum=""
 live_block_migration="no"
 numa=""
+tcmalloc="no"
 
 
 # parse CC options first
@@ -1140,6 +1141,10 @@ for opt do
   ;;
   --enable-live-block-migration) live_block_migration="yes"
   ;;
+  --disable-tcmalloc) tcmalloc="no"
+  ;;
+  --enable-tcmalloc) tcmalloc="yes"
+  ;;
   *)
       echo "ERROR: unknown option $opt"
       echo "Try '$0 --help' for more information"
@@ -1416,6 +1421,8 @@ Advanced options (experts only):
   --enable-live-block-migration  enable live block migration
   --disable-numa           disable libnuma support
   --enable-numa            enable libnuma support
+  --disable-tcmalloc       disable tcmalloc support
+  --enable-tcmalloc        enable tcmalloc support
 
 NOTE: The object files are built at the place where configure is launched
 EOF
@@ -3340,6 +3347,22 @@ EOF
 fi
 
 ##########################################
+# tcmalloc probe
+
+if test "$tcmalloc" = "yes" ; then
+  cat > $TMPC << EOF
+#include <stdlib.h>
+int main(void) { malloc(1); return 0; }
+EOF
+
+  if compile_prog "" "-ltcmalloc" ; then
+    LIBS="-ltcmalloc $LIBS"
+  else
+    feature_not_found "tcmalloc" "install gperftools devel"
+  fi
+fi
+
+##########################################
 # signalfd probe
 signalfd="no"
 cat > $TMPC << EOF
@@ -4451,6 +4474,7 @@ echo "snappy support    $snappy"
 echo "bzip2 support     $bzip2"
 echo "Live block migration $live_block_migration"
 echo "NUMA host support $numa"
+echo "tcmalloc support  $tcmalloc"
 
 if test "$sdl_too_old" = "yes"; then
 echo "-> Your SDL version is too old - please upgrade to have SDL support"
-- 
1.8.3.1

