On 7/31/19 1:32 AM, Jakub Jelinek wrote: > This broke a lot of tests. Whoops.
> The logs show > spawn -ignore SIGHUP /home/jakub/src/gcc/obj31/gcc/xgcc > -B/home/jakub/src/gcc/obj31/gcc/ c_lto_pr83954_0.o c_lto_pr83954_1.o > -fno-diagnostics-show- > caret -fno-diagnostics-show-line-numbers -fdiagnostics-color=never -O2 -flto > -flto-partition=1to1 -o gcc-dg-lto-pr83954-31.exe > make[4]: *** write jobserver: Bad file descriptor. Stop. > make[4]: *** Waiting for unfinished jobs.... > make[4]: *** write jobserver: Bad file descriptor. Stop. > lto-wrapper: fatal error: make returned 2 exit status > compilation terminated. > collect2: fatal error: lto-wrapper returned 1 exit status > compilation terminated. > compiler exited with status 1 > FAIL: gcc.dg/lto/pr83954 c_lto_pr83954_0.o-c_lto_pr83954_1.o link, -O2 -flto > -flto-partition=1to1 > and similar, e.g. for x86_64-linux it was following regressions, on > i686-linux also some tests in libgomp etc. > Is -flto now really using all available CPUs for each compilation? Yes, I can confirm that linking happens in N processed for each LTO test now. It's caused by fact that current Dejagnu machinery does not pass a make jobserver to gcc command invocations. On the other hand, our LTO tests are so tiny that we should have always very low number of partitions. > Without > jobserver that would like a fork-bomb, say if I have a CPU with 32 threads > and do make check -j32, does that mean there are 1024 lto1s? > Judging from http://gcc.gnu.org/ml/gcc-testresults/2019-07/msg03610.html > I'm not alone. One possible solution will be to adjust lto.exp: set LTO_OPTIONS [list \ {-O0 -flto -flto-partition=none -fuse-linker-plugin} \ {-O2 -flto -flto-partition=none -fuse-linker-plugin -fno-fat-lto-objects } \ {-O0 -flto -flto-partition=1to1 -fno-use-linker-plugin } \ {-O2 -flto -flto-partition=1to1 -fno-use-linker-plugin } \ and replace all -flto with -flto=1. But still, many individual tests set -flto by themselves. Another solution would be to disable the auto-detection with an environment variable: diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c index 353187c6043..bb6fb2b53ff 100644 --- a/gcc/lto-wrapper.c +++ b/gcc/lto-wrapper.c @@ -1423,7 +1423,7 @@ run_gcc (unsigned argc, char *argv[]) auto_parallel = 0; parallel = 0; } - else if (!jobserver && parallel) + else if (!jobserver && parallel && !getenv ("LTO_NO_AUTO_PARALLEL")) { /* If there's no explicit usage of jobserver and parallel is enabled, then automatically detect diff --git a/gcc/testsuite/lib/lto.exp b/gcc/testsuite/lib/lto.exp index 25c934731df..e303894e0b0 100644 --- a/gcc/testsuite/lib/lto.exp +++ b/gcc/testsuite/lib/lto.exp @@ -209,6 +209,8 @@ proc lto_init { args } { ] } } + + setenv LTO_NO_AUTO_PARALLEL 1 } # Can you Jakub test the patch or the s/-flto/-flto=1 solutions please? Thanks, Martin
