{Memory,Swap}Meter: add "compressed memory" metrics

For now, the semantics are mostly fit for Linux zswap subsystem. For
instance, we add the third swap usage metric that indicates the amount
of memory that is accounted to swap but in fact stored elsewhere. This
exactly matches the definition of frontswap/zswap, and is probably of
little use to all other platforms.

15 files changed, 71 insertions, 14 deletions

diff --git a/Action.c b/Action.c
index a67233cc..18c990e0 100644
--- a/Action.c
+++ b/Action.c
@@ -674,10 +674,11 @@ static Htop_Reaction actionHelp(State* st) {
    mvaddstr(line++, 0, "Memory bar:    ");
    addattrstr(CRT_colors[BAR_BORDER], "[");
    addbartext(CRT_colors[MEMORY_USED], "", "used");
+   addbartext(CRT_colors[MEMORY_COMPRESSED], "/", "compressed");
    addbartext(CRT_colors[MEMORY_BUFFERS_TEXT], "/", "buffers");
    addbartext(CRT_colors[MEMORY_SHARED], "/", "shared");
    addbartext(CRT_colors[MEMORY_CACHE], "/", "cache");
-   addbartext(CRT_colors[BAR_SHADOW], "                     ", "used");
+   addbartext(CRT_colors[BAR_SHADOW], "          ", "used");
    addbartext(CRT_colors[BAR_SHADOW], "/", "total");
    addattrstr(CRT_colors[BAR_BORDER], "]");
 
@@ -687,10 +688,11 @@ static Htop_Reaction actionHelp(State* st) {
    addbartext(CRT_colors[SWAP], "", "used");
 #ifdef HTOP_LINUX
    addbartext(CRT_colors[SWAP_CACHE], "/", "cache");
+   addbartext(CRT_colors[SWAP_FRONTSWAP], "/", "frontswap");
 #else
    addbartext(CRT_colors[SWAP_CACHE], "      ", "");
 #endif
-   addbartext(CRT_colors[BAR_SHADOW], "                                    ", "used");
+   addbartext(CRT_colors[BAR_SHADOW], "                          ", "used");
    addbartext(CRT_colors[BAR_SHADOW], "/", "total");
    addattrstr(CRT_colors[BAR_BORDER], "]");
 
diff --git a/CRT.c b/CRT.c
index 85a38115..a82fc8c1 100644
--- a/CRT.c
+++ b/CRT.c
@@ -163,6 +163,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [BAR_SHADOW] = A_BOLD | ColorPairGrayBlack,
       [SWAP] = ColorPair(Red, Black),
       [SWAP_CACHE] = ColorPair(Yellow, Black),
+      [SWAP_FRONTSWAP] = A_BOLD | ColorPairGrayBlack,
       [GRAPH_1] = A_BOLD | ColorPair(Cyan, Black),
       [GRAPH_2] = ColorPair(Cyan, Black),
       [MEMORY_USED] = ColorPair(Green, Black),
@@ -170,6 +171,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [MEMORY_BUFFERS_TEXT] = A_BOLD | ColorPair(Blue, Black),
       [MEMORY_CACHE] = ColorPair(Yellow, Black),
       [MEMORY_SHARED] = ColorPair(Magenta, Black),
+      [MEMORY_COMPRESSED] = A_BOLD | ColorPairGrayBlack,
       [HUGEPAGE_1] = ColorPair(Green, Black),
       [HUGEPAGE_2] = ColorPair(Yellow, Black),
       [HUGEPAGE_3] = ColorPair(Red, Black),
@@ -274,6 +276,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [BAR_SHADOW] = A_DIM,
       [SWAP] = A_BOLD,
       [SWAP_CACHE] = A_NORMAL,
+      [SWAP_FRONTSWAP] = A_DIM,
       [GRAPH_1] = A_BOLD,
       [GRAPH_2] = A_NORMAL,
       [MEMORY_USED] = A_BOLD,
@@ -281,6 +284,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [MEMORY_BUFFERS_TEXT] = A_NORMAL,
       [MEMORY_CACHE] = A_NORMAL,
       [MEMORY_SHARED] = A_NORMAL,
+      [MEMORY_COMPRESSED] = A_DIM,
       [HUGEPAGE_1] = A_BOLD,
       [HUGEPAGE_2] = A_NORMAL,
       [HUGEPAGE_3] = A_REVERSE | A_BOLD,
@@ -385,6 +389,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [BAR_SHADOW] = ColorPair(Black, White),
       [SWAP] = ColorPair(Red, White),
       [SWAP_CACHE] = ColorPair(Yellow, White),
+      [SWAP_FRONTSWAP] = A_BOLD | ColorPair(Black, White),
       [GRAPH_1] = A_BOLD | ColorPair(Blue, White),
       [GRAPH_2] = ColorPair(Blue, White),
       [MEMORY_USED] = ColorPair(Green, White),
@@ -392,6 +397,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [MEMORY_BUFFERS_TEXT] = ColorPair(Cyan, White),
       [MEMORY_CACHE] = ColorPair(Yellow, White),
       [MEMORY_SHARED] = ColorPair(Magenta, White),
+      [MEMORY_COMPRESSED] = A_BOLD | ColorPair(Black, White),
       [HUGEPAGE_1] = ColorPair(Green, White),
       [HUGEPAGE_2] = ColorPair(Yellow, White),
       [HUGEPAGE_3] = ColorPair(Red, White),
@@ -496,6 +502,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [BAR_SHADOW] = ColorPairGrayBlack,
       [SWAP] = ColorPair(Red, Black),
       [SWAP_CACHE] = ColorPair(Yellow, Black),
+      [SWAP_FRONTSWAP] = ColorPairGrayBlack,
       [GRAPH_1] = A_BOLD | ColorPair(Cyan, Black),
       [GRAPH_2] = ColorPair(Cyan, Black),
       [MEMORY_USED] = ColorPair(Green, Black),
@@ -503,6 +510,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [MEMORY_BUFFERS_TEXT] = ColorPair(Cyan, Black),
       [MEMORY_CACHE] = ColorPair(Yellow, Black),
       [MEMORY_SHARED] = ColorPair(Magenta, Black),
+      [MEMORY_COMPRESSED] = ColorPairGrayBlack,
       [HUGEPAGE_1] = ColorPair(Green, Black),
       [HUGEPAGE_2] = ColorPair(Yellow, Black),
       [HUGEPAGE_3] = ColorPair(Red, Black),
@@ -607,6 +615,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [BAR_SHADOW] = ColorPair(Cyan, Blue),
       [SWAP] = ColorPair(Red, Blue),
       [SWAP_CACHE] = A_BOLD | ColorPair(Yellow, Blue),
+      [SWAP_FRONTSWAP] = A_BOLD | ColorPair(Black, Blue),
       [GRAPH_1] = A_BOLD | ColorPair(Cyan, Blue),
       [GRAPH_2] = ColorPair(Cyan, Blue),
       [MEMORY_USED] = A_BOLD | ColorPair(Green, Blue),
@@ -614,6 +623,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [MEMORY_BUFFERS_TEXT] = A_BOLD | ColorPair(Cyan, Blue),
       [MEMORY_CACHE] = A_BOLD | ColorPair(Yellow, Blue),
       [MEMORY_SHARED] = A_BOLD | ColorPair(Magenta, Blue),
+      [MEMORY_COMPRESSED] = A_BOLD | ColorPair(Black, Blue),
       [HUGEPAGE_1] = A_BOLD | ColorPair(Green, Blue),
       [HUGEPAGE_2] = A_BOLD | ColorPair(Yellow, Blue),
       [HUGEPAGE_3] = A_BOLD | ColorPair(Red, Blue),
@@ -718,6 +728,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [BAR_SHADOW] = ColorPair(Cyan, Black),
       [SWAP] = ColorPair(Red, Black),
       [SWAP_CACHE] = ColorPair(Yellow, Black),
+      [SWAP_FRONTSWAP] = ColorPair(Yellow, Black),
       [GRAPH_1] = A_BOLD | ColorPair(Green, Black),
       [GRAPH_2] = ColorPair(Green, Black),
       [MEMORY_USED] = ColorPair(Green, Black),
@@ -725,6 +736,7 @@ static int CRT_colorSchemes[LAST_COLORSCHEME][LAST_COLORELEMENT] = {
       [MEMORY_BUFFERS_TEXT] = A_BOLD | ColorPair(Blue, Black),
       [MEMORY_CACHE] = ColorPair(Yellow, Black),
       [MEMORY_SHARED] = ColorPair(Magenta, Black),
+      [MEMORY_COMPRESSED] = ColorPair(Yellow, Black),
       [HUGEPAGE_1] = ColorPair(Green, Black),
       [HUGEPAGE_2] = ColorPair(Yellow, Black),
       [HUGEPAGE_3] = ColorPair(Red, Black),
diff --git a/CRT.h b/CRT.h
index 278c1e81..ae78c9c5 100644
--- a/CRT.h
+++ b/CRT.h
@@ -68,6 +68,7 @@ typedef enum ColorElements_ {
    TASKS_RUNNING,
    SWAP,
    SWAP_CACHE,
+   SWAP_FRONTSWAP,
    PROCESS,
    PROCESS_SHADOW,
    PROCESS_TAG,
@@ -95,6 +96,7 @@ typedef enum ColorElements_ {
    MEMORY_BUFFERS_TEXT,
    MEMORY_CACHE,
    MEMORY_SHARED,
+   MEMORY_COMPRESSED,
    HUGEPAGE_1,
    HUGEPAGE_2,
    HUGEPAGE_3,
diff --git a/MemoryMeter.c b/MemoryMeter.c
index 1dad1356..28c0be27 100644
--- a/MemoryMeter.c
+++ b/MemoryMeter.c
@@ -20,6 +20,7 @@ static const int MemoryMeter_attributes[] = {
    MEMORY_USED,
    MEMORY_BUFFERS,
    MEMORY_SHARED,
+   MEMORY_COMPRESSED,
    MEMORY_CACHE
 };
 
@@ -28,8 +29,9 @@ static void MemoryMeter_updateValues(Meter* this) {
    size_t size = sizeof(this->txtBuffer);
    int written;
 
-   /* shared and available memory are not supported on all platforms */
+   /* shared, compressed and available memory are not supported on all platforms */
    this->values[MEMORY_METER_SHARED] = NAN;
+   this->values[MEMORY_METER_COMPRESSED] = NAN;
    this->values[MEMORY_METER_AVAILABLE] = NAN;
    Platform_setMemoryValues(this);
 
@@ -38,7 +40,13 @@ static void MemoryMeter_updateValues(Meter* this) {
       "MEMORY_METER_AVAILABLE is not the last item in MemoryMeterValues");
    this->curItems = MEMORY_METER_AVAILABLE;
 
-   written = Meter_humanUnit(buffer, this->values[MEMORY_METER_USED], size);
+   /* we actually want to show "used + compressed" */
+   double used = this->values[MEMORY_METER_USED];
+   if (!isnan(this->values[MEMORY_METER_COMPRESSED])) {
+      used += this->values[MEMORY_METER_COMPRESSED];
+   }
+
+   written = Meter_humanUnit(buffer, used, size);
    METER_BUFFER_CHECK(buffer, size, written);
 
    METER_BUFFER_APPEND_CHR(buffer, size, '/');
@@ -69,6 +77,13 @@ static void MemoryMeter_display(const Object* cast, RichString* out) {
       RichString_appendAscii(out, CRT_colors[MEMORY_SHARED], buffer);
    }
 
+   /* compressed memory is not supported on all platforms */
+   if (!isnan(this->values[MEMORY_METER_COMPRESSED])) {
+      Meter_humanUnit(buffer, this->values[MEMORY_METER_COMPRESSED], sizeof(buffer));
+      RichString_appendAscii(out, CRT_colors[METER_TEXT], " compressed:");
+      RichString_appendAscii(out, CRT_colors[MEMORY_COMPRESSED], buffer);
+   }
+
    Meter_humanUnit(buffer, this->values[MEMORY_METER_CACHE], sizeof(buffer));
    RichString_appendAscii(out, CRT_colors[METER_TEXT], " cache:");
    RichString_appendAscii(out, CRT_colors[MEMORY_CACHE], buffer);
diff --git a/MemoryMeter.h b/MemoryMeter.h
index d8f5fdbc..b6568afc 100644
--- a/MemoryMeter.h
+++ b/MemoryMeter.h
@@ -13,9 +13,10 @@ typedef enum {
    MEMORY_METER_USED = 0,
    MEMORY_METER_BUFFERS = 1,
    MEMORY_METER_SHARED = 2,
-   MEMORY_METER_CACHE = 3,
-   MEMORY_METER_AVAILABLE = 4,
-   MEMORY_METER_ITEMCOUNT = 5, // number of entries in this enum
+   MEMORY_METER_COMPRESSED = 3,
+   MEMORY_METER_CACHE = 4,
+   MEMORY_METER_AVAILABLE = 5,
+   MEMORY_METER_ITEMCOUNT = 6, // number of entries in this enum
 } MemoryMeterValues;
 
 extern const MeterClass MemoryMeter_class;
diff --git a/SwapMeter.c b/SwapMeter.c
index fea8e88b..84e58a26 100644
--- a/SwapMeter.c
+++ b/SwapMeter.c
@@ -20,7 +20,8 @@ in the source distribution for its full text.
 
 static const int SwapMeter_attributes[] = {
    SWAP,
-   SWAP_CACHE
+   SWAP_CACHE,
+   SWAP_FRONTSWAP,
 };
 
 static void SwapMeter_updateValues(Meter* this) {
@@ -29,6 +30,7 @@ static void SwapMeter_updateValues(Meter* this) {
    int written;
 
    this->values[SWAP_METER_CACHE] = NAN;   /* 'cached' not present on all platforms */
+   this->values[SWAP_METER_FRONTSWAP] = NAN;   /* 'frontswap' not present on all platforms */
    Platform_setSwapValues(this);
 
    written = Meter_humanUnit(buffer, this->values[SWAP_METER_USED], size);
@@ -54,6 +56,12 @@ static void SwapMeter_display(const Object* cast, RichString* out) {
       RichString_appendAscii(out, CRT_colors[METER_TEXT], " cache:");
       RichString_appendAscii(out, CRT_colors[SWAP_CACHE], buffer);
    }
+
+   if (!isnan(this->values[SWAP_METER_FRONTSWAP])) {
+      Meter_humanUnit(buffer, this->values[SWAP_METER_FRONTSWAP], sizeof(buffer));
+      RichString_appendAscii(out, CRT_colors[METER_TEXT], " frontswap:");
+      RichString_appendAscii(out, CRT_colors[SWAP_FRONTSWAP], buffer);
+   }
 }
 
 const MeterClass SwapMeter_class = {
diff --git a/SwapMeter.h b/SwapMeter.h
index 162897fb..94b8dc85 100644
--- a/SwapMeter.h
+++ b/SwapMeter.h
@@ -12,7 +12,8 @@ in the source distribution for its full text.
 typedef enum {
    SWAP_METER_USED = 0,
    SWAP_METER_CACHE = 1,
-   SWAP_METER_ITEMCOUNT = 2, // number of entries in this enum
+   SWAP_METER_FRONTSWAP = 2,
+   SWAP_METER_ITEMCOUNT = 3, // number of entries in this enum
 } SwapMeterValues;
 
 extern const MeterClass SwapMeter_class;
diff --git a/darwin/Platform.c b/darwin/Platform.c
index deba7abb..20bfec26 100644
--- a/darwin/Platform.c
+++ b/darwin/Platform.c
@@ -294,6 +294,7 @@ void Platform_setMemoryValues(Meter* mtr) {
    mtr->values[MEMORY_METER_USED] = (double)(vm->active_count + vm->wire_count) * page_K;
    mtr->values[MEMORY_METER_BUFFERS] = (double)vm->purgeable_count * page_K;
    // mtr->values[MEMORY_METER_SHARED] = "shared memory, like tmpfs and shm"
+   // mtr->values[MEMORY_METER_COMPRESSED] = "compressed memory, like zswap on linux"
    mtr->values[MEMORY_METER_CACHE] = (double)vm->inactive_count * page_K;
    // mtr->values[MEMORY_METER_AVAILABLE] = "available memory"
 }
@@ -306,6 +307,8 @@ void Platform_setSwapValues(Meter* mtr) {
 
    mtr->total = swapused.xsu_total / 1024;
    mtr->values[SWAP_METER_USED] = swapused.xsu_used / 1024;
+   // mtr->values[SWAP_METER_CACHE] = "pages that are both in swap and RAM, like SwapCached on linux"
+   // mtr->values[SWAP_METER_FRONTSWAP] = "pages that are accounted to swap but stored elsewhere, like frontswap on linux"
 }
 
 void Platform_setZfsArcValues(Meter* this) {
diff --git a/dragonflybsd/Platform.c b/dragonflybsd/Platform.c
index ab21d365..99527642 100644
--- a/dragonflybsd/Platform.c
+++ b/dragonflybsd/Platform.c
@@ -215,6 +215,7 @@ void Platform_setMemoryValues(Meter* this) {
    this->values[MEMORY_METER_USED] = pl->usedMem;
    this->values[MEMORY_METER_BUFFERS] = pl->buffersMem;
    // this->values[MEMORY_METER_SHARED] = "shared memory, like tmpfs and shm"
+   // mtr->values[MEMORY_METER_COMPRESSED] = "compressed memory, like zswap on linux"
    this->values[MEMORY_METER_CACHE] = pl->cachedMem;
    // this->values[MEMORY_METER_AVAILABLE] = "available memory"
 }
@@ -223,7 +224,8 @@ void Platform_setSwapValues(Meter* this) {
    const ProcessList* pl = this->pl;
    this->total = pl->totalSwap;
    this->values[SWAP_METER_USED] = pl->usedSwap;
-   this->values[SWAP_METER_CACHE] = NAN;
+   // mtr->values[SWAP_METER_CACHE] = "pages that are both in swap and RAM, like SwapCached on linux"
+   // mtr->values[SWAP_METER_FRONTSWAP] = "pages that are accounted to swap but stored elsewhere, like frontswap on linux"
 }
 
 char* Platform_getProcessEnv(pid_t pid) {
diff --git a/freebsd/Platform.c b/freebsd/Platform.c
index 618ed6b4..cab80929 100644
--- a/freebsd/Platform.c
+++ b/freebsd/Platform.c
@@ -236,6 +236,7 @@ void Platform_setMemoryValues(Meter* this) {
    this->values[MEMORY_METER_USED] = pl->usedMem;
    this->values[MEMORY_METER_BUFFERS] = pl->buffersMem;
    this->values[MEMORY_METER_SHARED] = pl->sharedMem;
+   // this->values[MEMORY_METER_COMPRESSED] = "compressed memory, like zswap on linux"
    this->values[MEMORY_METER_CACHE] = pl->cachedMem;
    // this->values[MEMORY_METER_AVAILABLE] = "available memory"
 
@@ -254,7 +255,8 @@ void Platform_setSwapValues(Meter* this) {
    const ProcessList* pl = this->pl;
    this->total = pl->totalSwap;
    this->values[SWAP_METER_USED] = pl->usedSwap;
-   this->values[SWAP_METER_CACHE] = NAN;
+   // this->values[SWAP_METER_CACHE] = "pages that are both in swap and RAM, like SwapCached on linux"
+   // this->values[SWAP_METER_FRONTSWAP] = "pages that are accounted to swap but stored elsewhere, like frontswap on linux"
 }
 
 void Platform_setZfsArcValues(Meter* this) {
diff --git a/linux/Platform.c b/linux/Platform.c
index c14736bb..45fee392 100644
--- a/linux/Platform.c
+++ b/linux/Platform.c
@@ -359,6 +359,7 @@ void Platform_setMemoryValues(Meter* this) {
    this->values[MEMORY_METER_USED] = pl->usedMem;
    this->values[MEMORY_METER_BUFFERS] = pl->buffersMem;
    this->values[MEMORY_METER_SHARED] = pl->sharedMem;
+   // this->values[MEMORY_METER_COMPRESSED] = "compressed memory, like zswap on linux"
    this->values[MEMORY_METER_CACHE] = pl->cachedMem;
    this->values[MEMORY_METER_AVAILABLE] = pl->availableMem;
 
diff --git a/netbsd/Platform.c b/netbsd/Platform.c
index 9c9546fe..1cf16067 100644
--- a/netbsd/Platform.c
+++ b/netbsd/Platform.c
@@ -274,6 +274,7 @@ void Platform_setMemoryValues(Meter* this) {
    this->values[MEMORY_METER_USED] = pl->usedMem;
    this->values[MEMORY_METER_BUFFERS] = pl->buffersMem;
    // this->values[MEMORY_METER_SHARED] = "shared memory, like tmpfs and shm"
+   // this->values[MEMORY_METER_COMPRESSED] = "compressed memory, like zswap on linux"
    this->values[MEMORY_METER_CACHE] = pl->cachedMem;
    // this->values[MEMORY_METER_AVAILABLE] = "available memory"
 }
@@ -282,7 +283,8 @@ void Platform_setSwapValues(Meter* this) {
    const ProcessList* pl = this->pl;
    this->total = pl->totalSwap;
    this->values[SWAP_METER_USED] = pl->usedSwap;
-   this->values[SWAP_METER_CACHE] = NAN;
+   // this->values[SWAP_METER_CACHE] = "pages that are both in swap and RAM, like SwapCached on linux"
+   // this->values[SWAP_METER_FRONTSWAP] = "pages that are accounted to swap but stored elsewhere, like frontswap on linux"
 }
 
 char* Platform_getProcessEnv(pid_t pid) {
diff --git a/openbsd/Platform.c b/openbsd/Platform.c
index e49a0f81..707d2106 100644
--- a/openbsd/Platform.c
+++ b/openbsd/Platform.c
@@ -231,6 +231,7 @@ void Platform_setMemoryValues(Meter* this) {
    this->values[MEMORY_METER_USED] = usedMem;
    this->values[MEMORY_METER_BUFFERS] = buffersMem;
    // this->values[MEMORY_METER_SHARED] = "shared memory, like tmpfs and shm"
+   // this->values[MEMORY_METER_COMPRESSED] = "compressed memory, like zswap on linux"
    this->values[MEMORY_METER_CACHE] = cachedMem;
    // this->values[MEMORY_METER_AVAILABLE] = "available memory"
 }
@@ -239,7 +240,8 @@ void Platform_setSwapValues(Meter* this) {
    const ProcessList* pl = this->pl;
    this->total = pl->totalSwap;
    this->values[SWAP_METER_USED] = pl->usedSwap;
-   this->values[SWAP_METER_CACHE] = NAN;
+   // this->values[SWAP_METER_CACHE] = "pages that are both in swap and RAM, like SwapCached on linux"
+   // this->values[SWAP_METER_FRONTSWAP] = "pages that are accounted to swap but stored elsewhere, like frontswap on linux"
 }
 
 char* Platform_getProcessEnv(pid_t pid) {
diff --git a/pcp/Platform.c b/pcp/Platform.c
index 22963dda..87de2c2f 100644
--- a/pcp/Platform.c
+++ b/pcp/Platform.c
@@ -537,6 +537,7 @@ void Platform_setMemoryValues(Meter* this) {
    this->values[MEMORY_METER_USED] = pl->usedMem;
    this->values[MEMORY_METER_BUFFERS] = pl->buffersMem;
    this->values[MEMORY_METER_SHARED] = pl->sharedMem;
+   // this->values[MEMORY_METER_COMPRESSED] = "compressed memory, like zswap on linux"
    this->values[MEMORY_METER_CACHE] = pl->cachedMem;
    this->values[MEMORY_METER_AVAILABLE] = pl->availableMem;
 
@@ -556,6 +557,7 @@ void Platform_setSwapValues(Meter* this) {
    this->total = pl->totalSwap;
    this->values[SWAP_METER_USED] = pl->usedSwap;
    this->values[SWAP_METER_CACHE] = pl->cachedSwap;
+   // this->values[SWAP_METER_FRONTSWAP] = "pages that are accounted to swap but stored elsewhere, like frontswap on linux"
 }
 
 void Platform_setZramValues(Meter* this) {
diff --git a/solaris/Platform.c b/solaris/Platform.c
index f7ab6558..79b6a9ea 100644
--- a/solaris/Platform.c
+++ b/solaris/Platform.c
@@ -240,6 +240,7 @@ void Platform_setMemoryValues(Meter* this) {
    this->values[MEMORY_METER_USED] = pl->usedMem;
    this->values[MEMORY_METER_BUFFERS] = pl->buffersMem;
    // this->values[MEMORY_METER_SHARED] = "shared memory, like tmpfs and shm"
+   // this->values[MEMORY_METER_COMPRESSED] = "compressed memory, like zswap on linux"
    this->values[MEMORY_METER_CACHE] = pl->cachedMem;
    // this->values[MEMORY_METER_AVAILABLE] = "available memory"
 }
@@ -248,7 +249,8 @@ void Platform_setSwapValues(Meter* this) {
    const ProcessList* pl = this->pl;
    this->total = pl->totalSwap;
    this->values[SWAP_METER_USED] = pl->usedSwap;
-   this->values[SWAP_METER_CACHE] = NAN;
+   // this->values[SWAP_METER_CACHE] = "pages that are both in swap and RAM, like SwapCached on linux"
+   // this->values[SWAP_METER_FRONTSWAP] = "pages that are accounted to swap but stored elsewhere, like frontswap on linux"
 }
 
 void Platform_setZfsArcValues(Meter* this) {