| 1 | /* Pthread mutex tunable parameters. |
|---|---|
| 2 | Copyright (C) 2018-2022 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <https://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #if HAVE_TUNABLES |
| 20 | # define TUNABLE_NAMESPACE pthread |
| 21 | #include <pthread_mutex_conf.h> |
| 22 | #include <stdint.h> |
| 23 | #include <stdbool.h> |
| 24 | #include <unistd.h> /* Get STDOUT_FILENO for _dl_printf. */ |
| 25 | #include <elf/dl-tunables.h> |
| 26 | #include <nptl-stack.h> |
| 27 | |
| 28 | struct mutex_config __mutex_aconf = |
| 29 | { |
| 30 | /* The maximum number of times a thread should spin on the lock before |
| 31 | calling into kernel to block. */ |
| 32 | .spin_count = DEFAULT_ADAPTIVE_COUNT, |
| 33 | }; |
| 34 | libc_hidden_data_def (__mutex_aconf) |
| 35 | |
| 36 | static void |
| 37 | TUNABLE_CALLBACK (set_mutex_spin_count) (tunable_val_t *valp) |
| 38 | { |
| 39 | __mutex_aconf.spin_count = (int32_t) (valp)->numval; |
| 40 | } |
| 41 | |
| 42 | static void |
| 43 | TUNABLE_CALLBACK (set_stack_cache_size) (tunable_val_t *valp) |
| 44 | { |
| 45 | __nptl_stack_cache_maxsize = valp->numval; |
| 46 | } |
| 47 | |
| 48 | void |
| 49 | __pthread_tunables_init (void) |
| 50 | { |
| 51 | TUNABLE_GET (mutex_spin_count, int32_t, |
| 52 | TUNABLE_CALLBACK (set_mutex_spin_count)); |
| 53 | TUNABLE_GET (stack_cache_size, size_t, |
| 54 | TUNABLE_CALLBACK (set_stack_cache_size)); |
| 55 | } |
| 56 | #endif |
| 57 |