Add the -J/--detect-job-slots flag as an shorthand equivalent for -j$(nproc). The help message is deliberately left ambiguous so that we could change it to nproc + 1 in future, if desired.
Signed-off-by: Matt Staveley-Taylor <matt.stav.tay...@gmail.com> --- Browsing the mailing list I can see that the behaviour of -j with no arguments has been discussed a few times. Given it would affect backwards compatability to change how -j works, introducing a new flag seems appropriate. bootstrap.conf | 3 ++- src/main.c | 14 +++++++++++++- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/bootstrap.conf b/bootstrap.conf index 98a709a5..9716025e 100644 --- a/bootstrap.conf +++ b/bootstrap.conf @@ -62,4 +62,5 @@ getloadavg host-cpu-c-abi largefile make-glob -make-macros" +make-macros +nproc" diff --git a/src/main.c b/src/main.c index 15104212..49c329b2 100644 --- a/src/main.c +++ b/src/main.c @@ -15,6 +15,7 @@ You should have received a copy of the GNU General Public License along with this program. If not, see <https://www.gnu.org/licenses/>. */ #include "makeint.h" +#include "nproc.h" #include <assert.h> #if MK_OS_W32 @@ -297,6 +298,9 @@ static int warn_undefined_variables_flag; static int always_make_set = 0; int always_make_flag = 0; +/* If nonzero, detect the number of job slots based on the number of CPUs. */ +static int detect_job_slots_flag = 0; + /* If nonzero, we're in the "try to rebuild makefiles" phase. */ int rebuilding_makefiles = 0; @@ -360,6 +364,8 @@ static const char *const usage[] = N_("\ --jobserver-style=STYLE Select the style of jobserver to use.\n"), N_("\ + -J, --detect-job-slots Detect job slots based on number of CPU cores.\n"), + N_("\ -k, --keep-going Keep going when some targets can't be made.\n"), N_("\ -l [N], --load-average[=N], --max-load[=N]\n\ @@ -465,6 +471,7 @@ static struct command_switch switches[] = { 'E', strlist, &eval_strings, 1, 0, 0, 0, 0, 0, "eval", 0 }, { 'h', flag, &print_usage_flag, 0, 0, 0, 0, 0, 0, "help", 0 }, { 'i', flag, &ignore_errors_flag, 1, 1, 0, 0, 0, 0, "ignore-errors", 0 }, + { 'J', flag, &detect_job_slots_flag, 1, 1, 0, 0, 0, 0, "detect-job-slots", 0 }, { 'k', flag, &keep_going_flag, 1, 1, 0, 0, 0, &default_keep_going_flag, "keep-going", &keep_going_origin }, { 'L', flag, &check_symlink_flag, 1, 1, 0, 0, 0, 0, "check-symlink-times", 0 }, @@ -1616,7 +1623,12 @@ main (int argc, char **argv, char **envp) argv_slots = arg_job_slots; if (arg_job_slots == INVALID_JOB_SLOTS) - arg_job_slots = env_slots; + { + if (detect_job_slots_flag) + arg_job_slots = num_processors(NPROC_CURRENT_OVERRIDABLE); + else + arg_job_slots = env_slots; + } } if (print_usage_flag) -- 2.44.0
