[git commit] free: include SReclaimable in cached value

Denys Vlasenko vda.linux at googlemail.com
Tue Jun 25 16:53:10 UTC 2019


commit: https://git.busybox.net/busybox/commit/?id=9663bbd17ba3ab9f7921d7c46f07d177cb4a1435
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

I noticed that the 'used' values from busybox free and
procps-ng free differed so I looked into why. It turns
out that procps-ng uses the "SReclaimable" value as
part of the cached value.

This was changed in
procps-ng commit 05d751c4f076a2f0118b914c5e51cfbb4762ad8e

function                                             old     new   delta
free_main                                            633     653     +20

Signed-off-by: Lukas Rusak <lorusak at gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 procps/free.c | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/procps/free.c b/procps/free.c
index 3acfc4072..1e5d36742 100644
--- a/procps/free.c
+++ b/procps/free.c
@@ -44,6 +44,7 @@ struct globals {
 #else
 # define G_unit_steps 10
 #endif
+	unsigned long cached_kb, available_kb, reclaimable_kb;
 };
 /* Because of NOFORK, "globals" are not in global data */
 
@@ -53,27 +54,30 @@ 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 int parse_meminfo(unsigned long *cached_kb, unsigned long *available_kb)
+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;
+	int seen_cached_and_available_and_reclaimable;
 
 	fp = xfopen_for_read("/proc/meminfo");
-	*cached_kb = *available_kb = 0;
-	seen_cached_and_available = 2;
+	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", cached_kb) == 1)
-			if (--seen_cached_and_available == 0)
+		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", available_kb) == 1)
-			if (--seen_cached_and_available == 0)
+		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 == 0;
+	return seen_cached_and_available_and_reclaimable == 0;
 }
 
 int free_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -82,7 +86,6 @@ 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;
-	unsigned long cached_kb, available_kb;
 	int seen_available;
 
 #if ENABLE_DESKTOP
@@ -118,10 +121,11 @@ int free_main(int argc UNUSED_PARAM, char **argv IF_NOT_DESKTOP(UNUSED_PARAM))
 	/* 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;
+	seen_available = parse_meminfo(&G);
+	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;
 
 #define FIELDS_6 "%12llu %11llu %11llu %11llu %11llu %11llu\n"


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