On Sun, Dec 25, 2022 at 4:58 PM Steve Kargl via Gcc-patches
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/libst
