| 1 | /* |
| 2 | * Copyright (C) 2012 - Simon Marchi <simon.marchi@polymtl.ca> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License, version 2 only, as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 11 | * more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along with |
| 14 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #include <stddef.h> |
| 19 | #include <unistd.h> |
| 20 | |
| 21 | #include "defaults.h" |
| 22 | #include "macros.h" |
| 23 | |
| 24 | size_t default_channel_subbuf_size; |
| 25 | size_t default_metadata_subbuf_size; |
| 26 | size_t default_kernel_channel_subbuf_size; |
| 27 | size_t default_ust_pid_channel_subbuf_size; |
| 28 | size_t default_ust_uid_channel_subbuf_size; |
| 29 | |
| 30 | static void __attribute__((constructor)) init_defaults(void) |
| 31 | { |
| 32 | /* |
| 33 | * The libringbuffer won't accept subbuf sizes smaller than the page size. |
| 34 | * If the default subbuf size is smaller, replace it by the page size. |
| 35 | */ |
| 36 | long page_size = sysconf(_SC_PAGESIZE); |
| 37 | |
| 38 | if (page_size < 0) { |
| 39 | page_size = 0; |
| 40 | } |
| 41 | |
| 42 | default_channel_subbuf_size = |
| 43 | max(_DEFAULT_CHANNEL_SUBBUF_SIZE, page_size); |
| 44 | default_metadata_subbuf_size = |
| 45 | max(DEFAULT_METADATA_SUBBUF_SIZE, page_size); |
| 46 | default_kernel_channel_subbuf_size = |
| 47 | max(DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE, page_size); |
| 48 | default_ust_pid_channel_subbuf_size = |
| 49 | max(DEFAULT_UST_PID_CHANNEL_SUBBUF_SIZE, page_size); |
| 50 | default_ust_uid_channel_subbuf_size = |
| 51 | max(DEFAULT_UST_UID_CHANNEL_SUBBUF_SIZE, page_size); |
| 52 | } |