[PULL 56/92] configure: fix performance regression due to PIC objects

Paolo Bonzini posted 92 patches 5 years, 4 months ago
Maintainers: Fam Zheng <fam@euphon.net>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, "Alex Bennée" <alex.bennee@linaro.org>, Thomas Huth <thuth@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, Christian Borntraeger <borntraeger@de.ibm.com>, Markus Armbruster <armbru@redhat.com>, Bandan Das <bsd@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, Michael Roth <mdroth@linux.vnet.ibm.com>, Peter Maydell <peter.maydell@linaro.org>, Jason Wang <jasowang@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Sergio Lopez <slp@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Laurent Vivier <lvivier@redhat.com>, Hannes Reinecke <hare@suse.com>, Stefan Weil <sw@weilnetz.de>, Cleber Rosa <crosa@redhat.com>, Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>, David Hildenbrand <david@redhat.com>, Aurelien Jarno <aurelien@aurel32.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Eric Blake <eblake@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Alexander Bulekov <alxndr@bu.edu>, "Michael S. Tsirkin" <mst@redhat.com>, David Gibson <david@gibson.dropbear.id.au>, Max Reitz <mreitz@redhat.com>, Eduardo Habkost <ehabkost@redhat.com>, Sunil Muthuswamy <sunilmut@microsoft.com>, Richard Henderson <rth@twiddle.net>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Kevin Wolf <kwolf@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, Halil Pasic <pasic@linux.ibm.com>
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[PULL 56/92] configure: fix performance regression due to PIC objects
Posted by Paolo Bonzini 5 years, 4 months ago
Because most files in QEMU are grouped into static libraries, Meson conservatively
compiles them with -fPIC.  This is overkill and produces slowdowns up to 20% on
some TCG tests.

As a stopgap measure, use the b_staticpic option to limit the slowdown to
--enable-pie.  https://github.com/mesonbuild/meson/pull/7760 will allow
us to use b_staticpic=false and let Meson do the right thing.

Reported-by: Ahmed Karaman <ahmedkrmn@outlook.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200919155639.1045857-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 configure | 1 +
 1 file changed, 1 insertion(+)

diff --git a/configure b/configure
index fee5faa054..ac0dfdfac5 100755
--- a/configure
+++ b/configure
@@ -7849,6 +7849,7 @@ NINJA=${ninja:-$PWD/ninjatool} $meson setup \
         -Dwerror=$(if test "$werror" = yes; then echo true; else echo false; fi) \
         -Dstrip=$(if test "$strip_opt" = yes; then echo true; else echo false; fi) \
         -Db_pie=$(if test "$pie" = yes; then echo true; else echo false; fi) \
+        -Db_staticpic=$(if test "$pie" = yes; then echo true; else echo false; fi) \
         -Db_coverage=$(if test "$gcov" = yes; then echo true; else echo false; fi) \
 	-Dmalloc=$malloc -Dmalloc_trim=$malloc_trim \
 	-Dcocoa=$cocoa -Dmpath=$mpath -Dsdl=$sdl -Dsdl_image=$sdl_image \
-- 
2.26.2