From 5bc1f5ed04a56c4b33cf2854e1f3b0918b098cbf Mon Sep 17 00:00:00 2001
From: Hisham Muhammad <hisham@gobolinux.org>
Date: Sat, 28 Nov 2015 22:22:00 -0200
Subject: [PATCH 1/2] Account unreclaimable slab and shmem as used memory,
 reclaimable slab as cached memory.

Hopefully this presents a more truthful representation of
available vs. used memory on Linux.
See brndnmtthws/conky#82, #242, #67, #263.
---
 linux/LinuxProcessList.c | 42 ++++++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/linux/LinuxProcessList.c b/linux/LinuxProcessList.c
index 92259514..6724acff 100644
--- a/linux/LinuxProcessList.c
+++ b/linux/LinuxProcessList.c
@@ -621,6 +621,9 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, const char*
 
 static inline void LinuxProcessList_scanMemoryInfo(ProcessList* this) {
    unsigned long long int swapFree = 0;
+   unsigned long long int slab = 0;
+   unsigned long long int shmem = 0;
+   unsigned long long int sreclaimable = 0;
 
    FILE* file = fopen(PROCMEMINFOFILE, "r");
    if (file == NULL) {
@@ -629,33 +632,42 @@ static inline void LinuxProcessList_scanMemoryInfo(ProcessList* this) {
    char buffer[128];
    while (fgets(buffer, 128, file)) {
 
+      #define tryRead(label, variable) (String_startsWith(buffer, label) && sscanf(buffer + strlen(label), " %32llu kB", variable))
       switch (buffer[0]) {
       case 'M':
-         if (String_startsWith(buffer, "MemTotal:"))
-            sscanf(buffer, "MemTotal: %32llu kB", &this->totalMem);
-         else if (String_startsWith(buffer, "MemFree:"))
-            sscanf(buffer, "MemFree: %32llu kB", &this->freeMem);
-         else if (String_startsWith(buffer, "MemShared:"))
-            sscanf(buffer, "MemShared: %32llu kB", &this->sharedMem);
+         if (tryRead("MemTotal:", &this->totalMem)) {}
+         else if (tryRead("MemFree:", &this->freeMem)) {}
+         else if (tryRead("MemShared:", &this->sharedMem)) {}
          break;
       case 'B':
-         if (String_startsWith(buffer, "Buffers:"))
-            sscanf(buffer, "Buffers: %32llu kB", &this->buffersMem);
+         if (tryRead("Buffers:", &this->buffersMem)) {}
          break;
       case 'C':
-         if (String_startsWith(buffer, "Cached:"))
-            sscanf(buffer, "Cached: %32llu kB", &this->cachedMem);
+         if (tryRead("Cached:", &this->cachedMem)) {}
          break;
       case 'S':
-         if (String_startsWith(buffer, "SwapTotal:"))
-            sscanf(buffer, "SwapTotal: %32llu kB", &this->totalSwap);
-         if (String_startsWith(buffer, "SwapFree:"))
-            sscanf(buffer, "SwapFree: %32llu kB", &swapFree);
+         switch (buffer[1]) {
+         case 'w':
+            if (tryRead("SwapTotal:", &this->totalSwap)) {}
+            else if (tryRead("SwapFree:", &swapFree)) {}
+            break;
+         case 'l':
+            if (tryRead("Slab:", &slab)) {}
+            break;
+         case 'h':
+            if (tryRead("Shmem:", &shmem)) {}
+            break;
+         case 'R':
+            if (tryRead("SReclaimable:", &sreclaimable)) {}
+            break;
+         }
          break;
       }
+      #undef tryRead
    }
 
-   this->usedMem = this->totalMem - this->freeMem;
+   this->usedMem = this->totalMem - this->freeMem + (slab - sreclaimable) + shmem;
+   this->cachedMem = this->cachedMem + sreclaimable;
    this->usedSwap = this->totalSwap - swapFree;
    fclose(file);
 }

From a84aa2e78226563cd758711171c69c9c79131c53 Mon Sep 17 00:00:00 2001
From: Hisham Muhammad <hisham@gobolinux.org>
Date: Sun, 29 Nov 2015 23:55:31 -0200
Subject: [PATCH 2/2] Cached memory calculations, take 2.

Thanks to @OmegaPhil for discussion and reviewing.
---
 linux/LinuxProcessList.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/linux/LinuxProcessList.c b/linux/LinuxProcessList.c
index 6724acff..e939b4a9 100644
--- a/linux/LinuxProcessList.c
+++ b/linux/LinuxProcessList.c
@@ -621,7 +621,6 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, const char*
 
 static inline void LinuxProcessList_scanMemoryInfo(ProcessList* this) {
    unsigned long long int swapFree = 0;
-   unsigned long long int slab = 0;
    unsigned long long int shmem = 0;
    unsigned long long int sreclaimable = 0;
 
@@ -651,9 +650,6 @@ static inline void LinuxProcessList_scanMemoryInfo(ProcessList* this) {
             if (tryRead("SwapTotal:", &this->totalSwap)) {}
             else if (tryRead("SwapFree:", &swapFree)) {}
             break;
-         case 'l':
-            if (tryRead("Slab:", &slab)) {}
-            break;
          case 'h':
             if (tryRead("Shmem:", &shmem)) {}
             break;
@@ -666,8 +662,8 @@ static inline void LinuxProcessList_scanMemoryInfo(ProcessList* this) {
       #undef tryRead
    }
 
-   this->usedMem = this->totalMem - this->freeMem + (slab - sreclaimable) + shmem;
-   this->cachedMem = this->cachedMem + sreclaimable;
+   this->usedMem = this->totalMem - this->freeMem;
+   this->cachedMem = this->cachedMem + sreclaimable - shmem;
    this->usedSwap = this->totalSwap - swapFree;
    fclose(file);
 }