*
* Licensed under GPLv2, see file LICENSE in this source tree.
*/
+//config:config FREE
+//config: bool "free (2.4 kb)"
+//config: default y
+//config: select PLATFORM_LINUX #sysinfo()
+//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+//config: The shared memory column should be ignored; it is obsolete.
-/* getopt not needed */
+//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]")
struct globals {
unsigned mem_unit;
#if ENABLE_DESKTOP
- unsigned unit_steps;
-# define G_unit_steps G.unit_steps
+ uint8_t unit_steps;
+# define G_unit_steps g->unit_steps
#else
# define G_unit_steps 10
#endif
-} FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
-#define INIT_G() do { } while (0)
-
+};
+/* Because of NOFORK, "globals" are not in global data */
-static unsigned long long scale(unsigned long d)
+static unsigned long long scale(struct globals *g, unsigned long d)
{
- return ((unsigned long long)d * G.mem_unit) >> G_unit_steps;
+ 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(unsigned long *cached_kb, unsigned long *available_kb)
+{
+ char buf[60]; /* actual lines we expect are ~30 chars or less */
+ FILE *fp;
+ int seen_cached_and_available;
+
+ fp = xfopen_for_read("/proc/meminfo");
+ *cached_kb = *available_kb = 0;
+ seen_cached_and_available = 2;
+ while (fgets(buf, sizeof(buf), fp)) {
+ if (sscanf(buf, "Cached: %lu %*s\n", cached_kb) == 1)
+ if (--seen_cached_and_available == 0)
+ break;
+ if (sscanf(buf, "MemAvailable: %lu %*s\n", available_kb) == 1)
+ if (--seen_cached_and_available == 0)
+ break;
+ }
+ /* Have to close because of NOFORK */
+ fclose(fp);
+
+ return seen_cached_and_available == 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;
-
- INIT_G();
+ unsigned long long cached, cached_plus_free, available;
+ unsigned long cached_kb, available_kb;
+ int seen_available;
#if ENABLE_DESKTOP
G.unit_steps = 10;
}
}
#endif
-
- sysinfo(&info);
-
- /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
- G.mem_unit = (info.mem_unit ? info.mem_unit : 1);
-
- printf(" %13s%13s%13s%13s%13s\n",
+ printf(" %12s%12s%12s%12s%12s%12s\n"
+ "Mem: ",
"total",
"used",
"free",
- "shared", "buffers" /* swap and total don't have these columns */
- /* procps version 3.2.8 also shows "cached" column, but
- * sysinfo() does not provide this value, need to parse
- * /proc/meminfo instead and get "Cached: NNN kB" from there.
- */
+ "shared", "buff/cache", "available" /* swap and total don't have these columns */
);
-#define FIELDS_5 "%13llu%13llu%13llu%13llu%13llu\n"
-#define FIELDS_3 (FIELDS_5 + 2*6)
-#define FIELDS_2 (FIELDS_5 + 3*6)
+ sysinfo(&info);
+ /* Kernels prior to 2.4.x will return info.mem_unit==0, so cope... */
+ G.mem_unit = (info.mem_unit ? info.mem_unit : 1);
+ /* Extract cached and memavailable from /proc/meminfo and convert to mem_units */
+ seen_available = parse_meminfo(&cached_kb, &available_kb);
+ available = ((unsigned long long) available_kb * 1024) / G.mem_unit;
+ cached = ((unsigned long long) cached_kb * 1024) / G.mem_unit;
+ cached += info.bufferram;
+ cached_plus_free = cached + info.freeram;
+
+#define FIELDS_6 "%12llu%12llu%12llu%12llu%12llu%12llu\n"
+#define FIELDS_3 (FIELDS_6 + 3*6)
+#define FIELDS_2 (FIELDS_6 + 4*6)
- printf("Mem: ");
- printf(FIELDS_5,
- scale(info.totalram),
- scale(info.totalram - info.freeram),
- scale(info.freeram),
- scale(info.sharedram),
- scale(info.bufferram)
- );
- /* Show alternate, more meaningful busy/free numbers by counting
- * buffer cache as free memory (make it "-/+ buffers/cache"
- * if/when we add support for "cached" column): */
- printf("-/+ buffers: ");
- printf(FIELDS_2,
- scale(info.totalram - info.freeram - info.bufferram),
- scale(info.freeram + info.bufferram)
+ 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("Swap: ");
printf(FIELDS_3,
- scale(info.totalswap),
- scale(info.totalswap - info.freeswap),
- scale(info.freeswap)
+ scale(&G, info.totalswap), //total
+ scale(&G, info.totalswap - info.freeswap), //used
+ scale(&G, info.freeswap) //free
);
#endif
return EXIT_SUCCESS;
projects / oweals / busybox.git / blobdiff