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| author | Bruno Haible <bruno@clisp.org> | 2019-06-10 22:11:11 +0200 |
|---|---|---|
| committer | Bruno Haible <bruno@clisp.org> | 2019-06-10 22:11:11 +0200 |
| commit | 5dd3e60c55345c3c477492323a4395799e30e02b (patch) | |
| tree | f9b8796304bf4c0f4b3c3878fa71a9c76d327574 /lib/nproc.c | |
| parent | b827d8a6fab0c25eaf0c59b94c5bbef00efeeae5 (diff) | |
| download | gnulib-5dd3e60c55345c3c477492323a4395799e30e02b.tar.gz | |
nproc: Ensure nproc(NPROC_ALL) ≥ nproc(NPROC_CURRENT) with glibc ≥ 2.26.
Reported by Nikita Ermakov <arei@altlinux.org> in
<https://lists.gnu.org/archive/html/bug-gnulib/2019-06/msg00003.html>.
* lib/nproc.c (num_processors_ignoring_omp): Treat a return value of
sysconf (_SC_NPROCESSORS_CONF) == 2 like a return value == 1.
Diffstat (limited to 'lib/nproc.c')
| -rw-r--r-- | lib/nproc.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/lib/nproc.c b/lib/nproc.c index 77b8760271..b11690b570 100644 --- a/lib/nproc.c +++ b/lib/nproc.c @@ -216,8 +216,9 @@ num_processors_ignoring_omp (enum nproc_query query) Note! On Linux systems with glibc, the first and second number come from the /sys and /proc file systems (see glibc/sysdeps/unix/sysv/linux/getsysstats.c). - In some situations these file systems are not mounted, and the sysconf - call returns 1, which does not reflect the reality. */ + In some situations these file systems are not mounted, and the sysconf call + returns 1 or 2 (<https://sourceware.org/bugzilla/show_bug.cgi?id=21542>), + which does not reflect the reality. */ if (query == NPROC_CURRENT) { @@ -249,13 +250,13 @@ num_processors_ignoring_omp (enum nproc_query query) /* On Linux systems with glibc, this information comes from the /sys and /proc file systems (see glibc/sysdeps/unix/sysv/linux/getsysstats.c). In some situations these file systems are not mounted, and the - sysconf call returns 1. But we wish to guarantee that + sysconf call returns 1 or 2. But we wish to guarantee that num_processors (NPROC_ALL) >= num_processors (NPROC_CURRENT). */ - if (nprocs == 1) + if (nprocs == 1 || nprocs == 2) { unsigned long nprocs_current = num_processors_via_affinity_mask (); - if (nprocs_current > 0) + if (/* nprocs_current > 0 && */ nprocs_current > nprocs) nprocs = nprocs_current; } # endif |