From 4c772fcf7114d6ce20800c12bc377b490d267548 Mon Sep 17 00:00:00 2001 Message-Id: <4c772fcf7114d6ce20800c12bc377b490d267548.1566558648.git.pmatilai@redhat.com> In-Reply-To: <4d16d81a1af3e43b8392e7c335f616c9c0c6e41b.1566558648.git.pmatilai@redhat.com> References: <4d16d81a1af3e43b8392e7c335f616c9c0c6e41b.1566558648.git.pmatilai@redhat.com> From: Panu Matilainen Date: Fri, 23 Aug 2019 11:17:21 +0300 Subject: [PATCH 2/2] Cap number of threads on 32bit platforms, add a tunable (RhBug:1729382) On 32bit plaforms, address space is easily exhausted with multiple threads, causing arbitrary builds failure regressions (RhBug:1729382). Simply cap the number of threads to maximum of four on any 32bit platform to play it safe. It's still three more than we were able to use on older releases... In addition, introduce a separate tunable for tweaking the maximum number of threads just in case, defaulting to max CPUs available. --- build/parseSpec.c | 10 +++++++++- platform.in | 3 +++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/build/parseSpec.c b/build/parseSpec.c index 737a1233c..ab3ba9cae 100644 --- a/build/parseSpec.c +++ b/build/parseSpec.c @@ -1035,7 +1035,15 @@ static rpmSpec parseSpec(const char *specFile, rpmSpecFlags flags, #ifdef ENABLE_OPENMP /* Set number of OMP threads centrally */ - int ncpus = rpmExpandNumeric("%{?_smp_build_ncpus}"); + int ncpus = rpmExpandNumeric("%{?_smp_nthreads_max}"); +#if __WORDSIZE == 32 + /* On 32bit platforms, address space shortage is an issue. Play safe. */ + if (ncpus <= 0 || ncpus > 4) { + ncpus = 4; + rpmlog(RPMLOG_DEBUG, + "limiting number of threads to %d due to platform\n", ncpus); + } +#endif if (ncpus > 0) omp_set_num_threads(ncpus); #endif diff --git a/platform.in b/platform.in index db6d2382f..c70f44193 100644 --- a/platform.in +++ b/platform.in @@ -59,6 +59,9 @@ %_smp_mflags -j%{_smp_build_ncpus} +# Maximum number of CPU's to use for threads +%_smp_nthreads_max %{_smp_build_ncpus} + #============================================================================== # ---- Build policy macros. # -- 2.21.0