On Sun, Dec 25, 2022 at 4:58 PM Steve Kargl via Gcc-patches <gcc-patc...@gcc.gnu.org> wrote: > > On Wed, Dec 21, 2022 at 07:27:11PM -0500, Lipeng Zhu via Fortran wrote: > > This patch try to introduce the rwlock and split the read/write to > > unit_root tree and unit_cache with rwlock instead of the mutex to > > increase CPU efficiency. In the get_gfc_unit function, the percentage > > to step into the insert_unit function is around 30%, in most instances, > > we can get the unit in the phase of reading the unit_cache or unit_root > > tree. So split the read/write phase by rwlock would be an approach to > > make it more parallel. > > > > BTW, the IPC metrics can increase from 0.25 to 2.2 in the Intel > > SRP server with 220 cores. The benchmark we used is > > https://github.com/rwesson/NEAT > > > > The patch fails bootstrap on x86_64-*-freebsd. > > gmake[6]: Entering directory > '/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/src/c++17' > /bin/sh ../../libtool --tag CXX --tag disable-shared --mode=compile > /home/kargl/gcc/obj/./gcc/xgcc -shared-libgcc -B/home/kargl/gcc/obj/./gcc > -nostdinc++ -L/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/src > -L/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/src/.libs > -L/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/libsupc++/.libs > -B/home/kargl/work/x86_64-unknown-freebsd14.0/bin/ > -B/home/kargl/work/x86_64-unknown-freebsd14.0/lib/ -isystem > /home/kargl/work/x86_64-unknown-freebsd14.0/include -isystem > /home/kargl/work/x86_64-unknown-freebsd14.0/sys-include -fno-checking > -I/home/kargl/gcc/gcc/libstdc++-v3/../libgcc > -I/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/x86_64-unknown-freebsd14.0 > -I/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include > -I/home/kargl/gcc/gcc/libstdc++-v3/libsupc++ -std=gnu++17 -nostdinc++ > -prefer-pic -D_GLIBCXX_SHARED -fno-implicit-templates -Wall -Wextra > -Wwrite-strings -Wcast-qual -Wabi=2 -fdiagnostics-show-location=once > -ffunction-sections -fdata-sections -frandom-seed=floating_from_chars.lo > -fimplicit-templates -g -O2 -c -o floating_from_chars.lo > ../../../../../gcc/libstdc++-v3/src/c++17/floating_from_chars.cc > libtool: compile: /home/kargl/gcc/obj/./gcc/xgcc -shared-libgcc > -B/home/kargl/gcc/obj/./gcc -nostdinc++ > -L/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/src > -L/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/src/.libs > -L/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/libsupc++/.libs > -B/home/kargl/work/x86_64-unknown-freebsd14.0/bin/ > -B/home/kargl/work/x86_64-unknown-freebsd14.0/lib/ -isystem > /home/kargl/work/x86_64-unknown-freebsd14.0/include -isystem > /home/kargl/work/x86_64-unknown-freebsd14.0/sys-include -fno-checking > -I/home/kargl/gcc/gcc/libstdc++-v3/../libgcc > -I/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/x86_64-unknown-freebsd14.0 > -I/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include > -I/home/kargl/gcc/gcc/libstdc++-v3/libsupc++ -std=gnu++17 -nostdinc++ > -D_GLIBCXX_SHARED -fno-implicit-templates -Wall -Wextra -Wwrite-strings > -Wcast-qual -Wabi=2 -fdiagnostics-show-location=once -ffunction-sections > -fdata-sections -frandom-seed=floating_from_chars.lo -fimplicit-templates -g > -O2 -c ../../../../../gcc/libstdc++-v3/src/c++17/floating_from_chars.cc > -fPIC -DPIC -D_GLIBCXX_SHARED -o floating_from_chars.o > In file included from > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/memory_resource:40, > from > ../../../../../gcc/libstdc++-v3/src/c++17/floating_from_chars.cc:37: > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex: > In function 'int std::__glibcxx_rwlock_rdlock(pthread_rwlock**)': > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:80:3: > error: call of overloaded '__gthrw_pthread_rwlock_rdlock(pthread_rwlock**&)' > is ambiguous > 80 | _GLIBCXX_GTHRW(rwlock_rdlock) > | ^ > In file included from > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/x86_64-unknown-freebsd14.0/bits/gthr.h:148, > from > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/bits/std_mutex.h:41, > from > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:41: > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:80:3: > note: candidate: 'int std::__gthrw_pthread_rwlock_rdlock(pthread_rwlock**)' > 80 | _GLIBCXX_GTHRW(rwlock_rdlock) > | ^~~~~~~~~~~~~~ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/x86_64-unknown-freebsd14.0/bits/gthr-default.h:140:1: > note: candidate: 'int __gthrw_pthread_rwlock_rdlock(pthread_rwlock**)' > 140 | __gthrw(pthread_rwlock_rdlock) > | ^~~~~~~ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex: > In function 'int std::__glibcxx_rwlock_tryrdlock(pthread_rwlock**)': > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:81:3: > error: call of overloaded > '__gthrw_pthread_rwlock_tryrdlock(pthread_rwlock**&)' is ambiguous > 81 | _GLIBCXX_GTHRW(rwlock_tryrdlock) > | ^ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:81:3: > note: candidate: 'int > std::__gthrw_pthread_rwlock_tryrdlock(pthread_rwlock**)' > 81 | _GLIBCXX_GTHRW(rwlock_tryrdlock) > | ^~~~~~~~~~~~~~ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/x86_64-unknown-freebsd14.0/bits/gthr-default.h:141:1: > note: candidate: 'int __gthrw_pthread_rwlock_tryrdlock(pthread_rwlock**)' > 141 | __gthrw(pthread_rwlock_tryrdlock) > | ^~~~~~~ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex: > In function 'int std::__glibcxx_rwlock_wrlock(pthread_rwlock**)': > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:82:3: > error: call of overloaded '__gthrw_pthread_rwlock_wrlock(pthread_rwlock**&)' > is ambiguous > 82 | _GLIBCXX_GTHRW(rwlock_wrlock) > | ^ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:82:3: > note: candidate: 'int std::__gthrw_pthread_rwlock_wrlock(pthread_rwlock**)' > 82 | _GLIBCXX_GTHRW(rwlock_wrlock) > | ^~~~~~~~~~~~~~ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/x86_64-unknown-freebsd14.0/bits/gthr-default.h:142:1: > note: candidate: 'int __gthrw_pthread_rwlock_wrlock(pthread_rwlock**)' > 142 | __gthrw(pthread_rwlock_wrlock) > | ^~~~~~~ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex: > In function 'int std::__glibcxx_rwlock_trywrlock(pthread_rwlock**)': > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:83:3: > error: call of overloaded > '__gthrw_pthread_rwlock_trywrlock(pthread_rwlock**&)' is ambiguous > 83 | _GLIBCXX_GTHRW(rwlock_trywrlock) > | ^ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:83:3: > note: candidate: 'int > std::__gthrw_pthread_rwlock_trywrlock(pthread_rwlock**)' > 83 | _GLIBCXX_GTHRW(rwlock_trywrlock) > | ^~~~~~~~~~~~~~ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/x86_64-unknown-freebsd14.0/bits/gthr-default.h:143:1: > note: candidate: 'int __gthrw_pthread_rwlock_trywrlock(pthread_rwlock**)' > 143 | __gthrw(pthread_rwlock_trywrlock) > | ^~~~~~~ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex: > In function 'int std::__glibcxx_rwlock_unlock(pthread_rwlock**)': > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:84:3: > error: call of overloaded '__gthrw_pthread_rwlock_unlock(pthread_rwlock**&)' > is ambiguous > 84 | _GLIBCXX_GTHRW(rwlock_unlock) > | ^ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/shared_mutex:84:3: > note: candidate: 'int std::__gthrw_pthread_rwlock_unlock(pthread_rwlock**)' > 84 | _GLIBCXX_GTHRW(rwlock_unlock) > | ^~~~~~~~~~~~~~ > /home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/include/x86_64-unknown-freebsd14.0/bits/gthr-default.h:144:1: > note: candidate: 'int __gthrw_pthread_rwlock_unlock(pthread_rwlock**)' > 144 | __gthrw(pthread_rwlock_unlock) > | ^~~~~~~ > gmake[6]: *** [Makefile:585: floating_from_chars.lo] Error 1 > gmake[6]: Leaving directory > '/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/src/c++17' > gmake[5]: *** [Makefile:784: all-recursive] Error 1 > gmake[5]: Leaving directory > '/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3/src' > gmake[4]: *** [Makefile:576: all-recursive] Error 1 > gmake[4]: Leaving directory > '/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3' > gmake[3]: *** [Makefile:501: all] Error 2 > gmake[3]: Leaving directory > '/home/kargl/gcc/obj/x86_64-unknown-freebsd14.0/libstdc++-v3' > gmake[2]: *** [Makefile:18284: all-stage1-target-libstdc++-v3] Error 2 > gmake[2]: Leaving directory '/home/kargl/gcc/obj' > gmake[1]: *** [Makefile:26171: stage1-bubble] Error 2 > gmake[1]: Leaving directory '/home/kargl/gcc/obj' > gmake: *** [Makefile:26524: bootstrap] Error 2 > > -- > steve
libstdc++ implements shared mutex with pthread_rwlock, which can conflict with the pthread_rwlock usage in libgcc. Lipeng, please limit the pthread_rwlock usage in libgcc only when __cplusplus isn't defined. -- H.J.
