From c8e3922ad838751e45bf4b3cb8608b228ee83c71 Mon Sep 17 00:00:00 2001 From: Guillermo Rodriguez Date: Tue, 30 Oct 2018 13:49:51 +0100 Subject: free: add 'available' memory if provided by the kernel Show estimated available memory if this is provided by the kernel. See [1] for the full story. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=34e431b0ae398fc54ea69ff85ec700722c9da773 function old new delta free_main 537 633 +96 parse_cached_kb 85 - -85 ------------------------------------------------------------------------------ (add/remove: 0/1 grow/shrink: 1/0 up/down: 96/-85) Total: 11 bytes Signed-off-by: Guillermo Rodriguez Signed-off-by: Denys Vlasenko --- procps/free.c | 59 ++++++++++++++++++++++++++++++++++++----------------------- 1 file changed, 36 insertions(+), 23 deletions(-) (limited to 'procps') diff --git a/procps/free.c b/procps/free.c index 48139c4..e41601e 100644 --- a/procps/free.c +++ b/procps/free.c @@ -53,21 +53,27 @@ static unsigned long long scale(struct globals *g, unsigned long d) } /* NOINLINE reduces main() stack usage, which makes code smaller (on x86 at least) */ -static NOINLINE unsigned long parse_cached_kb(void) +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; - unsigned long cached = 0; + int seen_cached_and_available; fp = xfopen_for_read("/proc/meminfo"); - while (fgets(buf, sizeof(buf), fp) != NULL) { - if (sscanf(buf, "Cached: %lu %*s\n", &cached) == 1) - break; + *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 cached; + return seen_cached_and_available == 0; } int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; @@ -75,7 +81,9 @@ int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM)) { struct globals G; struct sysinfo info; - unsigned long long cached; + unsigned long long cached, cached_plus_free, available; + unsigned long cached_kb, available_kb; + int seen_available; #if ENABLE_DESKTOP G.unit_steps = 10; @@ -98,41 +106,46 @@ int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM)) } } #endif - printf(" %11s%11s%11s%11s%11s%11s\n" + printf(" %12s%12s%12s%12s%12s%12s\n" "Mem: ", "total", "used", "free", - "shared", "buffers", "cached" /* swap and total don't have these columns */ + "shared", "buff/cache", "available" /* swap and total don't have these columns */ ); 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 from /proc/meminfo and convert to mem_units */ - cached = ((unsigned long long) parse_cached_kb() * 1024) / G.mem_unit; + /* 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 "%11llu%11llu%11llu%11llu%11llu%11llu\n" +#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(FIELDS_6, scale(&G, info.totalram), //total - scale(&G, info.totalram - info.freeram), //used + scale(&G, info.totalram - cached_plus_free), //used scale(&G, info.freeram), //free scale(&G, info.sharedram), //shared - scale(&G, info.bufferram), //buffers - scale(&G, cached) //cached + scale(&G, cached), //buff/cache + scale(&G, available) //available ); - /* Show alternate, more meaningful busy/free numbers by counting + /* On kernels < 3.14, MemAvailable is not provided. + * Show alternate, more meaningful busy/free numbers by counting * buffer cache as free memory. */ - printf("-/+ buffers/cache:"); - cached += info.freeram; - cached += info.bufferram; - printf(FIELDS_2, - scale(&G, info.totalram - cached), //used - scale(&G, cached) //free - ); + 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, -- cgit v1.1