From 9ff499cdccedbb3fdd70a52d48aee7d183963f9c Mon Sep 17 00:00:00 2001
From: Steve <69524416+ab7pa@users.noreply.github.com>
Date: Thu, 10 Nov 2022 21:43:00 -0700
Subject: [PATCH] add kernel MemAvailable to Status page (#536)

add larger of kernel MemAvailable or MemFree to Status page.
This will show a value to be at least the size of unused RAM and
can be larger if RAM can instantly be freed up to start a new process.
---
 files/www/cgi-bin/status | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/files/www/cgi-bin/status b/files/www/cgi-bin/status
index 12e81a14..a7bea373 100755
--- a/files/www/cgi-bin/status
+++ b/files/www/cgi-bin/status
@@ -100,6 +100,22 @@ function get_default_gw()
     return "none"
 end
 
+function get_memavail()
+    local f = io.open("/proc/meminfo", "r")
+    if f then
+        for line in f:lines()
+        do
+            local memavail = line:match("^MemAvailable:%s+(%d+)%s+kB")
+            if memavail then
+                f:close()
+                return tonumber(memavail)
+            end
+        end
+        f:close()
+    end
+    return 0
+end
+
 function get_wifi_signal(wifiif)
     local signal = -1000
     local noise = -1000
@@ -385,22 +401,21 @@ if fspace < 100 then
 else
     fspace = fspace .. " KB"
 end
-vfs = nixio.fs.statvfs("/tmp")
-local tspace = vfs.bfree * vfs.bsize / 1024
-if tspace < 3000 then
-    tspace = "<blink><b>" .. tspace .. " KB</b></blink>"
-else
-    tspace = tspace .. " KB"
+
+local rspace = sysinfo.freeram / 1024
+local mavail = get_memavail()
+if rspace < mavail then
+    rspace = mavail
 end
-local rspace = (sysinfo.freeram + sysinfo.bufferram) / 1024
+
 if rspace < 500 then
     rspace = "<blink><b>" .. rspace .. " KB</b></blink>"
 else
     rspace = rspace .. " KB"
 end
 
-col2[#col2 + 1] = "<th align=right valign=top><nobr>load average</nobr><br><nobr>free space</nobr></th><td>" .. string.format("%.2f, %.2f, %.2f", sysinfo.loads[1], sysinfo.loads[2], sysinfo.loads[3]) .. "<br><nobr>flash = " .. fspace .. "</nobr><br><nobr>/tmp = " .. tspace .. "</nobr><br><nobr>memory = " .. rspace .. "</nobr></td>";
-col2[#col2 + 1] = "<th align=right valign=top>Host Entries</th><td><nobr>Total = " .. host_total .. "<nobr><br><nobr>Nodes = " .. host_nodes .. "<nobr></td>"
+col2[#col2 + 1] = "<th align=right valign=top><nobr>load average</nobr><br><nobr>available space</nobr></th><td>" .. string.format("%.2f, %.2f, %.2f", sysinfo.loads[1], sysinfo.loads[2], sysinfo.loads[3]) .. "<br><nobr>flash = " .. fspace .. "</nobr><br><nobr>memory = " .. rspace .. "</nobr></td>";
+col2[#col2 + 1] = "<th align=right valign=top>Host Entries</th><td><nobr>Total = " .. host_total .. "</nobr><br><nobr>Nodes = " .. host_nodes .. "<nobr></td>"
 
 -- now print the tables