| /*- |
| * Copyright 2009 Colin Percival |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * |
| * This file was originally written by Colin Percival as part of the Tarsnap |
| * online backup system. |
| */ |
| #include "scrypt_platform.h" |
| |
| #include <sys/types.h> |
| #include <sys/resource.h> |
| |
| #ifdef HAVE_SYS_PARAM_H |
| #include <sys/param.h> |
| #endif |
| #ifdef HAVE_SYSCTL_HW_USERMEM |
| #include <sys/sysctl.h> |
| #endif |
| #ifdef HAVE_SYS_SYSINFO_H |
| #include <sys/sysinfo.h> |
| #endif |
| |
| #include <errno.h> |
| #include <stddef.h> |
| #include <stdint.h> |
| #include <unistd.h> |
| |
| #ifdef DEBUG |
| #include <stdio.h> |
| #endif |
| |
| #include "memlimit.h" |
| |
| #ifdef HAVE_SYSCTL_HW_USERMEM |
| static int |
| memlimit_sysctl_hw_usermem(size_t * memlimit) |
| { |
| int mib[2]; |
| uint8_t usermembuf[8]; |
| size_t usermemlen = 8; |
| uint64_t usermem; |
| |
| /* Ask the kernel how much RAM we have. */ |
| mib[0] = CTL_HW; |
| mib[1] = HW_USERMEM; |
| if (sysctl(mib, 2, usermembuf, &usermemlen, NULL, 0)) |
| return (1); |
| |
| /* |
| * Parse as either a uint64_t or a uint32_t based on the length of |
| * output the kernel reports having copied out. It appears that all |
| * systems providing a sysctl interface for reading integers copy |
| * them out as system-endian values, so we don't need to worry about |
| * parsing them. |
| */ |
| if (usermemlen == sizeof(uint64_t)) |
| usermem = *(uint64_t *)usermembuf; |
| else if (usermemlen == sizeof(uint32_t)) |
| usermem = *(uint32_t *)usermembuf; |
| else |
| return (1); |
| |
| /* Return the sysctl value, but clamp to SIZE_MAX if necessary. */ |
| #if UINT64_MAX > SIZE_MAX |
| if (usermem > SIZE_MAX) |
| *memlimit = SIZE_MAX; |
| else |
| *memlimit = usermem; |
| #else |
| *memlimit = usermem; |
| #endif |
| |
| /* Success! */ |
| return (0); |
| } |
| #endif |
| |
| /* If we don't HAVE_STRUCT_SYSINFO, we can't use sysinfo. */ |
| #ifndef HAVE_STRUCT_SYSINFO |
| #undef HAVE_SYSINFO |
| #endif |
| |
| /* If we don't HAVE_STRUCT_SYSINFO_TOTALRAM, we can't use sysinfo. */ |
| #ifndef HAVE_STRUCT_SYSINFO_TOTALRAM |
| #undef HAVE_SYSINFO |
| #endif |
| |
| #ifdef HAVE_SYSINFO |
| static int |
| memlimit_sysinfo(size_t * memlimit) |
| { |
| struct sysinfo info; |
| uint64_t totalmem; |
| |
| /* Get information from the kernel. */ |
| if (sysinfo(&info)) |
| return (1); |
| totalmem = info.totalram; |
| |
| /* If we're on a modern kernel, adjust based on mem_unit. */ |
| #ifdef HAVE_STRUCT_SYSINFO_MEM_UNIT |
| totalmem = totalmem * info.mem_unit; |
| #endif |
| |
| /* Return the value, but clamp to SIZE_MAX if necessary. */ |
| #if UINT64_MAX > SIZE_MAX |
| if (totalmem > SIZE_MAX) |
| *memlimit = SIZE_MAX; |
| else |
| *memlimit = totalmem; |
| #else |
| *memlimit = totalmem; |
| #endif |
| |
| /* Success! */ |
| return (0); |
| } |
| #endif /* HAVE_SYSINFO */ |
| |
| static int |
| memlimit_rlimit(size_t * memlimit) |
| { |
| struct rlimit rl; |
| uint64_t memrlimit; |
| |
| /* Find the least of... */ |
| memrlimit = (uint64_t)(-1); |
| |
| /* ... RLIMIT_AS... */ |
| #ifdef RLIMIT_AS |
| if (getrlimit(RLIMIT_AS, &rl)) |
| return (1); |
| if ((rl.rlim_cur != RLIM_INFINITY) && |
| ((uint64_t)rl.rlim_cur < memrlimit)) |
| memrlimit = rl.rlim_cur; |
| #endif |
| |
| /* ... RLIMIT_DATA... */ |
| if (getrlimit(RLIMIT_DATA, &rl)) |
| return (1); |
| if ((rl.rlim_cur != RLIM_INFINITY) && |
| ((uint64_t)rl.rlim_cur < memrlimit)) |
| memrlimit = rl.rlim_cur; |
| |
| /* ... and RLIMIT_RSS. */ |
| #ifdef RLIMIT_RSS |
| if (getrlimit(RLIMIT_RSS, &rl)) |
| return (1); |
| if ((rl.rlim_cur != RLIM_INFINITY) && |
| ((uint64_t)rl.rlim_cur < memrlimit)) |
| memrlimit = rl.rlim_cur; |
| #endif |
| |
| /* Return the value, but clamp to SIZE_MAX if necessary. */ |
| #if UINT64_MAX > SIZE_MAX |
| if (memrlimit > SIZE_MAX) |
| *memlimit = SIZE_MAX; |
| else |
| *memlimit = memrlimit; |
| #else |
| *memlimit = memrlimit; |
| #endif |
| |
| /* Success! */ |
| return (0); |
| } |
| |
| #ifdef _SC_PHYS_PAGES |
| |
| /* Some systems define _SC_PAGESIZE instead of _SC_PAGE_SIZE. */ |
| #ifndef _SC_PAGE_SIZE |
| #define _SC_PAGE_SIZE _SC_PAGESIZE |
| #endif |
| |
| static int |
| memlimit_sysconf(size_t * memlimit) |
| { |
| long pagesize; |
| long physpages; |
| uint64_t totalmem; |
| |
| /* Set errno to 0 in order to distinguish "no limit" from "error". */ |
| errno = 0; |
| |
| /* Read the two limits. */ |
| if (((pagesize = sysconf(_SC_PAGE_SIZE)) == -1) || |
| ((physpages = sysconf(_SC_PHYS_PAGES)) == -1)) { |
| /* Did an error occur? */ |
| /* TODO: wrap ENOSYS with autoconf detection testing. */ |
| if (errno != 0 && errno != ENOSYS) |
| return (1); |
| |
| /* If not, there is no limit. */ |
| totalmem = (uint64_t)(-1); |
| } else { |
| /* Compute the limit. */ |
| totalmem = (uint64_t)(pagesize) * (uint64_t)(physpages); |
| } |
| |
| /* Return the value, but clamp to SIZE_MAX if necessary. */ |
| #if UINT64_MAX > SIZE_MAX |
| if (totalmem > SIZE_MAX) |
| *memlimit = SIZE_MAX; |
| else |
| *memlimit = totalmem; |
| #else |
| *memlimit = totalmem; |
| #endif |
| |
| /* Success! */ |
| return (0); |
| } |
| #endif |
| |
| int |
| memtouse(size_t maxmem, double maxmemfrac, size_t * memlimit) |
| { |
| size_t sysctl_memlimit, sysinfo_memlimit, rlimit_memlimit; |
| size_t sysconf_memlimit; |
| size_t memlimit_min; |
| size_t memavail; |
| |
| /* Get memory limits. */ |
| #ifdef HAVE_SYSCTL_HW_USERMEM |
| if (memlimit_sysctl_hw_usermem(&sysctl_memlimit)) |
| return (1); |
| #else |
| sysctl_memlimit = (size_t)(-1); |
| #endif |
| #ifdef HAVE_SYSINFO |
| if (memlimit_sysinfo(&sysinfo_memlimit)) |
| return (1); |
| #else |
| sysinfo_memlimit = (size_t)(-1); |
| #endif |
| if (memlimit_rlimit(&rlimit_memlimit)) |
| return (1); |
| #ifdef _SC_PHYS_PAGES |
| if (memlimit_sysconf(&sysconf_memlimit)) |
| return (1); |
| #else |
| sysconf_memlimit = (size_t)(-1); |
| #endif |
| |
| #ifdef DEBUG |
| fprintf(stderr, "Memory limits are %zu %zu %zu %zu\n", |
| sysctl_memlimit, sysinfo_memlimit, rlimit_memlimit, |
| sysconf_memlimit); |
| #endif |
| |
| /* Find the smallest of them. */ |
| memlimit_min = (size_t)(-1); |
| if (memlimit_min > sysctl_memlimit) |
| memlimit_min = sysctl_memlimit; |
| if (memlimit_min > sysinfo_memlimit) |
| memlimit_min = sysinfo_memlimit; |
| if (memlimit_min > rlimit_memlimit) |
| memlimit_min = rlimit_memlimit; |
| if (memlimit_min > sysconf_memlimit) |
| memlimit_min = sysconf_memlimit; |
| |
| /* Only use the specified fraction of the available memory. */ |
| if ((maxmemfrac > 0.5) || (maxmemfrac == 0.0)) |
| maxmemfrac = 0.5; |
| memavail = maxmemfrac * memlimit_min; |
| |
| /* Don't use more than the specified maximum. */ |
| if ((maxmem > 0) && (memavail > maxmem)) |
| memavail = maxmem; |
| |
| /* But always allow at least 1 MiB. */ |
| if (memavail < 1048576) |
| memavail = 1048576; |
| |
| #ifdef DEBUG |
| fprintf(stderr, "Allowing up to %zu memory to be used\n", memavail); |
| #endif |
| |
| /* Return limit via the provided pointer. */ |
| *memlimit = memavail; |
| return (0); |
| } |