----- On Apr 19, 2019, at 8:41 AM, Mathieu Desnoyers [email protected] wrote:
> ----- On Apr 19, 2019, at 6:38 AM, Ingo Molnar [email protected] wrote: > >> * Mathieu Desnoyers <[email protected]> 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 <[email protected]> >>> Cc: Shuah Khan <[email protected]> >>> Cc: Thomas Gleixner <[email protected]> >>> Cc: Joel Fernandes <[email protected]> >>> Cc: Peter Zijlstra <[email protected]> >>> Cc: Catalin Marinas <[email protected]> >>> Cc: Dave Watson <[email protected]> >>> Cc: Will Deacon <[email protected]> >>> Cc: Andi Kleen <[email protected]> >>> Cc: [email protected] >>> Cc: "H . Peter Anvin" <[email protected]> >>> Cc: Chris Lameter <[email protected]> >>> Cc: Russell King <[email protected]> >>> Cc: Michael Kerrisk <[email protected]> >>> Cc: "Paul E . McKenney" <[email protected]> >>> Cc: Paul Turner <[email protected]> >>> Cc: Boqun Feng <[email protected]> >>> Cc: Josh Triplett <[email protected]> >>> Cc: Steven Rostedt <[email protected]> >>> Cc: Ben Maurer <[email protected]> >>> Cc: Andy Lutomirski <[email protected]> >>> Cc: Andrew Morton <[email protected]> >>> Cc: Linus Torvalds <[email protected]> >>> --- >>> 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. It looks like gcc-8 optimize away the target of asm goto labels when there are more than one of them on x86-64. I'll try to come up with a simpler reproducer. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
