| Message ID | 20200919155639.1045857-1-pbonzini@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | configure: fix performance regression due to PIC objects | expand |
Cc'ing Aleksandar as Ahmed is away. On 9/19/20 5:56 PM, Paolo Bonzini wrote: > 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> > --- > configure | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/configure b/configure > index 0004c46525..0786144043 100755 > --- a/configure > +++ b/configure > @@ -7414,6 +7414,7 @@ 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=$malloc_trim -Dsparse=$sparse \ > -Dkvm=$kvm -Dhax=$hax -Dwhpx=$whpx -Dhvf=$hvf \ >
On 9/19/20 8:56 AM, Paolo Bonzini wrote: > 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> > --- > configure | 1 + > 1 file changed, 1 insertion(+) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/configure b/configure index 0004c46525..0786144043 100755 --- a/configure +++ b/configure @@ -7414,6 +7414,7 @@ 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=$malloc_trim -Dsparse=$sparse \ -Dkvm=$kvm -Dhax=$hax -Dwhpx=$whpx -Dhvf=$hvf \
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> --- configure | 1 + 1 file changed, 1 insertion(+)