luci-mod-status: use available and cached memory for progress bars

Fixes: #1148

Uses available and cached memory from /proc/meminfo via procd, and carefully
handles the cases where they are nil or zero, so as to not require specific
linux or procd versions to function

MemAvailable is a better estimate than free + buffered/cached, see:
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=34e431b0

Also adds a new progressbar that shows cached memory if not nil

Signed-off-by: Zachary Cook <zachcook1991@gmail.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/modules/luci-mod-status/htdocs/luci-static/resources/view/status/include/20_memory.js b/modules/luci-mod-status/htdocs/luci-static/resources/view/status/include/20_memory.js
index 9baf0420d7..2e84774346 100644
--- a/modules/luci-mod-status/htdocs/luci-static/resources/view/status/include/20_memory.js
+++ b/modules/luci-mod-status/htdocs/luci-static/resources/view/status/include/20_memory.js
@@ -31,11 +31,14 @@ return L.Class.extend({
 		    swap = L.isObject(systeminfo.swap) ? systeminfo.swap : {};
 
 		var fields = [
-			_('Total Available'), (mem.total && mem.free && mem.buffered) ? mem.free + mem.buffered : null,
+			_('Total Available'), (mem.available) ? mem.available : (mem.total && mem.free && mem.buffered) ? mem.free + mem.buffered : null,
 			_('Free'),            (mem.total && mem.free) ? mem.free : null,
 			_('Buffered'),        (mem.total && mem.buffered) ? mem.buffered : null
 		];
 
+		if (mem.cached)
+			fields.push(_('Cached'), mem.cached);
+
 		if (swap.total > 0)
 			fields.push(_('Swap free'), swap.free);