| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini free implementation for busybox |
| * |
| * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> |
| * |
| * Licensed under GPLv2, see file LICENSE in this source tree. |
| */ |
| //config:config FREE |
| //config: bool "free (3.1 kb)" |
| //config: default y |
| //config: help |
| //config: free displays the total amount of free and used physical and swap |
| //config: memory in the system, as well as the buffers used by the kernel. |
| //config: The shared memory column should be ignored; it is obsolete. |
| |
| //applet:IF_FREE(APPLET_NOFORK(free, free, BB_DIR_USR_BIN, BB_SUID_DROP, free)) |
| |
| //kbuild:lib-$(CONFIG_FREE) += free.o |
| |
| //usage:#define free_trivial_usage |
| //usage: "" IF_DESKTOP("[-b/k/m/g]") |
| //usage:#define free_full_usage "\n\n" |
| //usage: "Display the amount of free and used system memory" |
| //usage: |
| //usage:#define free_example_usage |
| //usage: "$ free\n" |
| //usage: " total used free shared buffers\n" |
| //usage: " Mem: 257628 248724 8904 59644 93124\n" |
| //usage: " Swap: 128516 8404 120112\n" |
| //usage: "Total: 386144 257128 129016\n" |
| |
| #include "libbb.h" |
| #ifdef __linux__ |
| # include <sys/sysinfo.h> |
| #endif |
| |
| struct globals { |
| unsigned mem_unit; |
| #if ENABLE_DESKTOP |
| uint8_t unit_steps; |
| # define G_unit_steps g->unit_steps |
| #else |
| # define G_unit_steps 10 |
| #endif |
| unsigned long cached_kb, available_kb, reclaimable_kb; |
| }; |
| /* Because of NOFORK, "globals" are not in global data */ |
| |
| static unsigned long long scale(struct globals *g, unsigned long d) |
| { |
| return ((unsigned long long)d * g->mem_unit) >> G_unit_steps; |
| } |
| |
| /* NOINLINE reduces main() stack usage, which makes code smaller (on x86 at least) */ |
| static NOINLINE unsigned int parse_meminfo(struct globals *g) |
| { |
| char buf[60]; /* actual lines we expect are ~30 chars or less */ |
| FILE *fp; |
| int seen_cached_and_available_and_reclaimable; |
| |
| fp = xfopen_for_read("/proc/meminfo"); |
| g->cached_kb = g->available_kb = g->reclaimable_kb = 0; |
| seen_cached_and_available_and_reclaimable = 3; |
| while (fgets(buf, sizeof(buf), fp)) { |
| if (sscanf(buf, "Cached: %lu %*s\n", &g->cached_kb) == 1) |
| if (--seen_cached_and_available_and_reclaimable == 0) |
| break; |
| if (sscanf(buf, "MemAvailable: %lu %*s\n", &g->available_kb) == 1) |
| if (--seen_cached_and_available_and_reclaimable == 0) |
| break; |
| if (sscanf(buf, "SReclaimable: %lu %*s\n", &g->reclaimable_kb) == 1) |
| if (--seen_cached_and_available_and_reclaimable == 0) |
| break; |
| } |
| /* Have to close because of NOFORK */ |
| fclose(fp); |
| |
| return seen_cached_and_available_and_reclaimable == 0; |
| } |
| |
| int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM)) |
| { |
| struct globals G; |
| struct sysinfo info; |
| unsigned long long cached, cached_plus_free, available; |
| int seen_available; |
| |
| #if ENABLE_DESKTOP |
| G.unit_steps = 10; |
| if (argv[1] && argv[1][0] == '-') { |
| switch (argv[1][1]) { |
| case 'b': |
| G.unit_steps = 0; |
| break; |
| case 'k': /* 2^10 */ |
| /* G.unit_steps = 10; - already is */ |
| break; |
| case 'm': /* 2^20 */ |
| G.unit_steps = 20; |
| break; |
| case 'g': /* 2^30 */ |
| G.unit_steps = 30; |
| break; |
| default: |
| bb_show_usage(); |
| } |
| } |
| #endif |
| printf(" %12s%12s%12s%12s%12s%12s\n" |
| "Mem: ", |
| "total", |
| "used", |
| "free", |
| "shared", "buff/cache", "available" /* swap and total don't have these columns */ |
| ); |
| |
| sysinfo(&info); |
| /* Extract cached and memavailable from /proc/meminfo and convert to mem_units */ |
| seen_available = parse_meminfo(&G); |
| G.mem_unit = (info.mem_unit ? info.mem_unit : 1); /* kernels < 2.4.x return mem_unit==0, so cope */ |
| available = ((unsigned long long) G.available_kb * 1024) / G.mem_unit; |
| cached = ((unsigned long long) G.cached_kb * 1024) / G.mem_unit; |
| cached += info.bufferram; |
| cached += ((unsigned long long) G.reclaimable_kb * 1024) / G.mem_unit; |
| cached_plus_free = cached + info.freeram; |
| |
| /* In case (long long * G.mem_unit) can overflow, this can be used to reduce the chances */ |
| #if 0 //ENABLE_DESKTOP |
| while (!(G.mem_unit & 1) && G.unit_steps != 0) { |
| G.mem_unit >>= 1; |
| G.unit_steps--; |
| //bb_error_msg("mem_unit:%d unit_steps:%d", G.mem_unit, G.unit_steps); |
| } |
| #endif |
| |
| #define FIELDS_6 "%12llu %11llu %11llu %11llu %11llu %11llu\n" |
| #define FIELDS_3 (FIELDS_6 + 6 + 7 + 7) |
| #define FIELDS_2 (FIELDS_6 + 6 + 7 + 7 + 7) |
| |
| printf(FIELDS_6, |
| scale(&G, info.totalram), //total |
| scale(&G, info.totalram - cached_plus_free), //used |
| scale(&G, info.freeram), //free |
| scale(&G, info.sharedram), //shared |
| scale(&G, cached), //buff/cache |
| scale(&G, available) //available |
| ); |
| /* On kernels < 3.14, MemAvailable is not provided. |
| * Show alternate, more meaningful busy/free numbers by counting |
| * buffer cache as free memory. */ |
| if (!seen_available) { |
| printf("-/+ buffers/cache: "); |
| printf(FIELDS_2, |
| scale(&G, info.totalram - cached_plus_free), //used |
| scale(&G, cached_plus_free) //free |
| ); |
| } |
| #if BB_MMU |
| printf("Swap: "); |
| printf(FIELDS_3, |
| scale(&G, info.totalswap), //total |
| scale(&G, info.totalswap - info.freeswap), //used |
| scale(&G, info.freeswap) //free |
| ); |
| #endif |
| return EXIT_SUCCESS; |
| } |