fixes #16 adds LinuxMemory with MemAvailable

Author: threez

lib/vmstat.rb

@@ -15,6 +15,7 @@ module Vmstat
   autoload :Disk,             "vmstat/disk"
   autoload :LinuxDisk,        "vmstat/linux_disk"
   autoload :Memory,           "vmstat/memory"
+  autoload :LinuxMemory,      "vmstat/linux_memory"
   autoload :Task,             "vmstat/task"
   autoload :LoadAverage,      "vmstat/load_average"
   autoload :ProcFS,           "vmstat/procfs"

lib/vmstat/linux_memory.rb

@@ -0,0 +1,13 @@
+# @attr [Fixnum] available
+#   The estimated available memory (linux)
+#   See: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=34e431b0ae398fc54ea69ff85ec700722c9da773
+class Vmstat::LinuxMemory < Vmstat::Memory
+  attr_accessor :available
+
+  # Calculate the available bytes based of the active pages.
+  # @return [Fixnum] active bytes
+  def available_bytes
+    available * pagesize
+  end
+end
+

lib/vmstat/memory.rb

@@ -15,7 +15,7 @@ module Vmstat
   # @attr [Fixnum] pageouts
   #   The number of pageouts.
   class Memory < Struct.new(:pagesize, :wired, :active, :inactive, :free,
-                            :pageins, :pageouts, :available)
+                            :pageins, :pageouts)
     # Calculate the wired bytes based of the wired pages.
     # @return [Fixnum] wired bytes
     def wired_bytes
@@ -40,16 +40,23 @@ def free_bytes
       free * pagesize
     end
 
-    # Calculate the available bytes based of the active pages.
-    # @return [Fixnum] active bytes
-    def available_bytes
-      available * pagesize
-    end
-
     # Calculate the total bytes based of all pages
     # @return [Fixnum] total bytes
     def total_bytes
       (wired + active + inactive + free) * pagesize
     end
   end
+
+  # @attr [Fixnum] available
+  #   The estimated available memory (linux)
+  #   See: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=34e431b0ae398fc54ea69ff85ec700722c9da773
+  class LinuxMemory < Memory
+    attr_accessor :available
+
+    # Calculate the available bytes based of the active pages.
+    # @return [Fixnum] active bytes
+    def available_bytes
+      available * pagesize
+    end
+  end
 end

lib/vmstat/procfs.rb

@@ -45,6 +45,7 @@ def cpu
     #   Vmstat.memory # => #<struct Vmstat::Memory ...>
     def memory
       @pagesize ||= Vmstat.pagesize
+      has_available = false
 
       total = free = active = inactive = pageins = pageouts = available = 0
       procfs_file("meminfo") do |file|
@@ -56,7 +57,9 @@ def memory
           case name
             when "MemTotal" then total = pages
             when "MemFree" then free = pages
-            when "MemAvailable" then available = pages
+            when "MemAvailable"
+                available = pages
+                has_available = true
             when "Active" then active = pages
             when "Inactive" then inactive = pages
           end
@@ -75,7 +78,11 @@ def memory
         end
       end
 
-      Memory.new @pagesize, total-free-active-inactive, active, inactive, free, pageins, pageouts, available
+      mem_klass = has_available ? LinuxMemory : Memory
+      mem_klass.new(@pagesize, total-free-active-inactive, active,
+                    inactive, free, pageins, pageouts).tap do |mem|
+        mem.available = available if has_available
+      end
     end
 
     # Fetches the information for all available network devices.

lib/vmstat/version.rb

@@ -1,3 +1,3 @@
 module Vmstat
-  VERSION = "2.2.1"
+  VERSION = "2.3.0"
 end

spec/memavail_procfs/meminfo

@@ -0,0 +1,43 @@
+MemTotal:        1884428 kB
+MemFree:          252452 kB
+MemAvailable:     458368 kB
+Buffers:              76 kB
+Cached:           321752 kB
+SwapCached:            4 kB
+Active:          1307912 kB
+Inactive:         177976 kB
+Active(anon):    1074332 kB
+Inactive(anon):   106548 kB
+Active(file):     233580 kB
+Inactive(file):    71428 kB
+Unevictable:       21100 kB
+Mlocked:           21100 kB
+SwapTotal:       2097148 kB
+SwapFree:        2097140 kB
+Dirty:                60 kB
+Writeback:             0 kB
+AnonPages:       1185204 kB
+Mapped:           101384 kB
+Shmem:              8760 kB
+Slab:              59380 kB
+SReclaimable:      27064 kB
+SUnreclaim:        32316 kB
+KernelStack:        4528 kB
+PageTables:        21592 kB
+NFS_Unstable:          0 kB
+Bounce:                0 kB
+WritebackTmp:          0 kB
+CommitLimit:     3039360 kB
+Committed_AS:    2906080 kB
+VmallocTotal:   34359738367 kB
+VmallocUsed:      269704 kB
+VmallocChunk:   34359466492 kB
+HardwareCorrupted:     0 kB
+AnonHugePages:    659456 kB
+HugePages_Total:       0
+HugePages_Free:        0
+HugePages_Rsvd:        0
+HugePages_Surp:        0
+Hugepagesize:       2048 kB
+DirectMap4k:       26624 kB
+DirectMap2M:     2070528 kB

spec/memavail_procfs/vmstat

@@ -0,0 +1,89 @@
+nr_free_pages 107062
+nr_inactive_anon 60
+nr_active_anon 1557
+nr_inactive_file 8341
+nr_active_file 4939
+nr_unevictable 0
+nr_mlock 0
+nr_anon_pages 1579
+nr_mapped 1461
+nr_file_pages 13346
+nr_dirty 1
+nr_writeback 0
+nr_slab_reclaimable 1628
+nr_slab_unreclaimable 1885
+nr_page_table_pages 101
+nr_kernel_stack 88
+nr_unstable 0
+nr_bounce 0
+nr_vmscan_write 0
+nr_vmscan_immediate_reclaim 0
+nr_writeback_temp 0
+nr_isolated_anon 0
+nr_isolated_file 0
+nr_shmem 67
+nr_dirtied 185
+nr_written 182
+nr_anon_transparent_hugepages 0
+nr_dirty_threshold 24392
+nr_dirty_background_threshold 12196
+pgpgin 64599
+pgpgout 1104
+pswpin 0
+pswpout 0
+pgalloc_dma 2
+pgalloc_normal 190973
+pgalloc_high 0
+pgalloc_movable 0
+pgfree 298439
+pgactivate 5802
+pgdeactivate 0
+pgfault 581461
+pgmajfault 42
+pgrefill_dma 0
+pgrefill_normal 0
+pgrefill_high 0
+pgrefill_movable 0
+pgsteal_dma 0
+pgsteal_normal 0
+pgsteal_high 0
+pgsteal_movable 0
+pgscan_kswapd_dma 0
+pgscan_kswapd_normal 0
+pgscan_kswapd_high 0
+pgscan_kswapd_movable 0
+pgscan_direct_dma 0
+pgscan_direct_normal 0
+pgscan_direct_high 0
+pgscan_direct_movable 0
+pginodesteal 0
+slabs_scanned 0
+kswapd_steal 0
+kswapd_inodesteal 0
+kswapd_low_wmark_hit_quickly 0
+kswapd_high_wmark_hit_quickly 0
+kswapd_skip_congestion_wait 0
+pageoutrun 1
+allocstall 0
+pgrotated 0
+compact_blocks_moved 0
+compact_pages_moved 0
+compact_pagemigrate_failed 0
+compact_stall 0
+compact_fail 0
+compact_success 0
+htlb_buddy_alloc_success 0
+htlb_buddy_alloc_fail 0
+unevictable_pgs_culled 0
+unevictable_pgs_scanned 0
+unevictable_pgs_rescued 0
+unevictable_pgs_mlocked 0
+unevictable_pgs_munlocked 0
+unevictable_pgs_cleared 0
+unevictable_pgs_stranded 0
+unevictable_pgs_mlockfreed 0
+thp_fault_alloc 0
+thp_fault_fallback 0
+thp_collapse_alloc 0
+thp_collapse_alloc_failed 0
+thp_split 0

spec/vmstat/memavail_spec.rb

@@ -0,0 +1,31 @@
+require 'spec_helper'
+
+describe Vmstat::LinuxMemory do
+  let(:procfs) do
+    Class.new do
+      extend Vmstat::ProcFS
+
+      def self.procfs_path
+        File.expand_path("../../memavail_procfs", __FILE__)
+      end
+    end
+  end
+
+  context "#memory" do
+    subject { procfs.memory }
+    
+    it { should be_a(Vmstat::LinuxMemory) }
+    if `getconf PAGESIZE`.chomp.to_i == 4096
+      it do
+        should == Vmstat::LinuxMemory.new(4096, 36522, 326978, 
+                                          44494, 63113, 64599, 1104)
+      end
+
+      it "should have the right total" do
+        (subject.wired_bytes + subject.active_bytes +
+         subject.inactive_bytes + subject.free_bytes).should == 1929654272
+      end
+    end
+  end
+end
+