From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Subject: Re: [PATCH for 5.1 3/3] rseq/selftests: Adapt number of threads to the number of detected cpus Date: Fri, 19 Apr 2019 08:41:22 -0400 (EDT) Message-ID: <1444419838.71.1555677682502.JavaMail.zimbra@efficios.com> References: <20190305194755.2602-1-mathieu.desnoyers@efficios.com> <20190305194755.2602-4-mathieu.desnoyers@efficios.com> <20190419103847.GA111210@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190419103847.GA111210@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar Cc: Thomas Gleixner , linux-kernel , linux-api , Peter Zijlstra , "Paul E . McKenney" , Boqun Feng , Andy Lutomirski , Dave Watson , Paul Turner , Andrew Morton , Russell King , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , Chris Lameter , Ben Maurer , rostedt , Josh Triplett , Linus Torvalds , Catalin Marinas , Will List-Id: linux-api@vger.kernel.org ----- On Apr 19, 2019, at 6:38 AM, Ingo Molnar mingo@kernel.org wrote: > * Mathieu Desnoyers wrote: > >> On smaller systems, running a test with 200 threads can take a long >> time on machines with smaller number of CPUs. >> >> Detect the number of online cpus at test runtime, and multiply that >> by 6 to have 6 rseq threads per cpu preempting each other. >> >> Signed-off-by: Mathieu Desnoyers >> Cc: Shuah Khan >> Cc: Thomas Gleixner >> Cc: Joel Fernandes >> Cc: Peter Zijlstra >> Cc: Catalin Marinas >> Cc: Dave Watson >> Cc: Will Deacon >> Cc: Andi Kleen >> Cc: linux-kselftest@vger.kernel.org >> Cc: "H . Peter Anvin" >> Cc: Chris Lameter >> Cc: Russell King >> Cc: Michael Kerrisk >> Cc: "Paul E . McKenney" >> Cc: Paul Turner >> Cc: Boqun Feng >> Cc: Josh Triplett >> Cc: Steven Rostedt >> Cc: Ben Maurer >> Cc: Andy Lutomirski >> Cc: Andrew Morton >> Cc: Linus Torvalds >> --- >> tools/testing/selftests/rseq/run_param_test.sh | 7 +++++-- >> 1 file changed, 5 insertions(+), 2 deletions(-) >> >> diff --git a/tools/testing/selftests/rseq/run_param_test.sh >> b/tools/testing/selftests/rseq/run_param_test.sh >> index 3acd6d75ff9f..e426304fd4a0 100755 >> --- a/tools/testing/selftests/rseq/run_param_test.sh >> +++ b/tools/testing/selftests/rseq/run_param_test.sh >> @@ -1,6 +1,8 @@ >> #!/bin/bash >> # SPDX-License-Identifier: GPL-2.0+ or MIT >> >> +NR_CPUS=`grep '^processor' /proc/cpuinfo | wc -l` >> + >> EXTRA_ARGS=${@} >> >> OLDIFS="$IFS" >> @@ -28,15 +30,16 @@ IFS="$OLDIFS" >> >> REPS=1000 >> SLOW_REPS=100 >> +NR_THREADS=$((6*${NR_CPUS})) >> >> function do_tests() >> { >> local i=0 >> while [ "$i" -lt "${#TEST_LIST[@]}" ]; do >> echo "Running test ${TEST_NAME[$i]}" >> - ./param_test ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || exit 1 >> + ./param_test ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} >> || exit 1 >> echo "Running compare-twice test ${TEST_NAME[$i]}" >> - ./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} ${@} ${EXTRA_ARGS} || >> exit 1 >> + ./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} >> ${EXTRA_ARGS} || exit 1 >> let "i++" >> done >> } > > BTW., when trying to build the rseq self-tests I get this build failure: > > dagon:~/tip/tools/testing/selftests/rseq> make > gcc -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./ -shared > -fPIC rseq.c -lpthread -o > /home/mingo/tip/tools/testing/selftests/rseq/librseq.so > gcc -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./ basic_test.c > -lpthread -lrseq -o /home/mingo/tip/tools/testing/selftests/rseq/basic_test > gcc -O2 -Wall -g -I./ -I../../../../usr/include/ -L./ -Wl,-rpath=./ > basic_percpu_ops_test.c -lpthread -lrseq -o > /home/mingo/tip/tools/testing/selftests/rseq/basic_percpu_ops_test > /usr/bin/ld: /tmp/ccuHTWnZ.o: in function `rseq_cmpeqv_storev': > /home/mingo/tip/tools/testing/selftests/rseq/./rseq-x86.h:84: undefined > reference to `.L8' > /usr/bin/ld: /home/mingo/tip/tools/testing/selftests/rseq/./rseq-x86.h:84: > undefined reference to `.L49' > /usr/bin/ld: /tmp/ccuHTWnZ.o: in function `rseq_cmpnev_storeoffp_load': > /home/mingo/tip/tools/testing/selftests/rseq/./rseq-x86.h:141: undefined > reference to `.L57' > /usr/bin/ld: /tmp/ccuHTWnZ.o:(__rseq_failure+0x8): undefined reference to `.L8' > /usr/bin/ld: /tmp/ccuHTWnZ.o:(__rseq_failure+0x14): undefined reference to > `.L49' > /usr/bin/ld: /tmp/ccuHTWnZ.o:(__rseq_failure+0x20): undefined reference to > `.L55' > collect2: error: ld returned 1 exit status > make: *** [Makefile:22: > /home/mingo/tip/tools/testing/selftests/rseq/basic_percpu_ops_test] Error 1 > > Is this a known problem, or do I miss something from my build environment > perhaps? Vanilla 64-bit Ubuntu 18.10 (Cosmic). It works fine with gcc-7 (gcc version 7.3.0 (Ubuntu 7.3.0-16ubuntu3)) but indeed I get the same failure with gcc-8 (gcc version 8.0.1 20180414 (experimental) [trunk revision 259383] (Ubuntu 8-20180414-1ubuntu2)). Thanks for reporting! I will investigate. Mathieu > > Thanks, > > Ingo -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com