--- a/xpcom/base/SystemMemoryReporter.cpp
+++ b/xpcom/base/SystemMemoryReporter.cpp
@@ -17,17 +17,16 @@
 #include "nsHashKeys.h"
 
 #include <dirent.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
-#include <errno.h>
 
 // This file implements a Linux-specific, system-wide memory reporter.  It
 // gathers all the useful memory measurements obtainable from the OS in a
 // single place, giving a high-level view of memory consumption for the entire
 // machine/device.
 //
 // Other memory reporters measure part of a single process's memory consumption.
 // This reporter is different in that it measures memory consumption of many
@@ -109,34 +108,30 @@ IsAnonymous(const nsACString& aName)
          StringBeginsWith(aName, NS_LITERAL_CSTRING("[stack:"));
 }
 
 class SystemReporter MOZ_FINAL : public nsIMemoryReporter
 {
 public:
   NS_DECL_THREADSAFE_ISUPPORTS
 
-#define REPORT_WITH_CLEANUP(_path, _amount, _desc, _cleanup)                  \
+#define REPORT(_path, _amount, _desc)                                         \
   do {                                                                        \
     size_t amount = _amount;  /* evaluate _amount only once */                \
     if (amount > 0) {                                                         \
       nsresult rv;                                                            \
       rv = aHandleReport->Callback(NS_LITERAL_CSTRING("System"), _path,       \
                                    KIND_NONHEAP, UNITS_BYTES, amount, _desc,  \
                                    aData);                                    \
       if (NS_WARN_IF(NS_FAILED(rv))) {                                        \
-        _cleanup;                                                             \
         return rv;                                                            \
       }                                                                       \
     }                                                                         \
   } while (0)
 
-#define REPORT(_path, _amount, _desc) \
-    REPORT_WITH_CLEANUP(_path, _amount, _desc, (void)0)
-
   NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,
                             nsISupports* aData)
   {
     if (!Preferences::GetBool("memory.system_memory_reporter")) {
       return NS_OK;
     }
 
     // Read relevant fields from /proc/meminfo.
@@ -153,20 +148,17 @@ public:
     REPORT(NS_LITERAL_CSTRING("mem/other"), other, NS_LITERAL_CSTRING(
 "Memory which is neither owned by any user-space process nor free. Note that "
 "this includes memory holding cached files from the disk which can be "
 "reclaimed by the OS at any time."));
 
     REPORT(NS_LITERAL_CSTRING("mem/free"), memFree, NS_LITERAL_CSTRING(
 "Memory which is free and not being used for any purpose."));
 
-    // Report reserved memory not included in memTotal.
-    rv = CollectPmemReports(aHandleReport, aData);
-
-    return rv;
+    return NS_OK;
   }
 
 private:
   // Keep this in sync with SystemReporter::kindPathSuffixes!
   enum ProcessSizeKind {
     AnonymousOutsideBrk  = 0,
     AnonymousBrkHeap     = 1,
     SharedLibrariesRX    = 2,
@@ -504,117 +496,16 @@ private:
       REPORT(path, *aPss, aDescription);
     } else {
       *aPss = 0;
     }
 
     return NS_OK;
   }
 
-  nsresult CollectPmemReports(nsIHandleReportCallback* aHandleReport,
-                              nsISupports* aData)
-  {
-    // The pmem subsystem allocates physically contiguous memory for
-    // interfacing with hardware.  In order to ensure availability,
-    // this memory is reserved during boot, and allocations are made
-    // within these regions at runtime.
-    //
-    // There are typically several of these pools allocated at boot.
-    // The /sys/kernel/pmem_regions directory contains a subdirectory
-    // for each one.  Within each subdirectory, the files we care
-    // about are "size" (the total amount of physical memory) and
-    // "mapped_regions" (a list of the current allocations within that
-    // area).
-    DIR* d = opendir("/sys/kernel/pmem_regions");
-    if (!d) {
-      if (NS_WARN_IF(errno != ENOENT)) {
-        return NS_ERROR_FAILURE;
-      }
-      // If ENOENT, system doesn't use pmem.
-      return NS_OK;
-    }
-
-    struct dirent* ent;
-    while ((ent = readdir(d))) {
-      const char* name = ent->d_name;
-      uint64_t size;
-      int scanned;
-
-      // Skip "." and ".." (and any other dotfiles).
-      if (name[0] == '.') {
-        continue;
-      }
-
-      // Read the total size.  The file gives the size in decimal and
-      // hex, in the form "13631488(0xd00000)"; we parse the former.
-      nsPrintfCString sizePath("/sys/kernel/pmem_regions/%s/size", name);
-      FILE* sizeFile = fopen(sizePath.get(), "r");
-      if (NS_WARN_IF(!sizeFile)) {
-        continue;
-      }
-      scanned = fscanf(sizeFile, "%"SCNu64, &size);
-      if (NS_WARN_IF(scanned != 1)) {
-        continue;
-      }
-      fclose(sizeFile);
-
-      // Read mapped regions; format described below.
-      uint64_t freeSize = size;
-      nsPrintfCString regionsPath("/sys/kernel/pmem_regions/%s/mapped_regions",
-                                  name);
-      FILE* regionsFile = fopen(regionsPath.get(), "r");
-      if (regionsFile) {
-        static const size_t bufLen = 4096;
-        char buf[bufLen];
-        while (fgets(buf, bufLen, regionsFile)) {
-          int pid;
-
-          // Skip header line.
-          if (strncmp(buf, "pid #", 5) == 0) {
-            continue;
-          }
-          // Line format: "pid N:" + zero or more "(Start,Len) ".
-          // N is decimal; Start and Len are in hex.
-          scanned = sscanf(buf, "pid %d", &pid);
-          if (NS_WARN_IF(scanned != 1)) {
-            continue;
-          }
-          for (const char* nextParen = strchr(buf, '(');
-               nextParen != nullptr;
-               nextParen = strchr(nextParen + 1, '(')) {
-            uint64_t mapStart, mapLen;
-
-            scanned = sscanf(nextParen + 1, "%"SCNx64",%"SCNx64,
-                             &mapStart, &mapLen);
-            if (NS_WARN_IF(scanned != 2)) {
-              break;
-            }
-
-            nsPrintfCString path("mem/pmem/used/%s/segment(pid=%d, "
-                                 "offset=0x%"PRIx64")", name, pid, mapStart);
-            nsPrintfCString desc("Physical memory reserved for the \"%s\" pool "
-                                 "and allocated to a buffer.", name);
-            REPORT_WITH_CLEANUP(path, mapLen, desc,
-                                (fclose(regionsFile), closedir(d)));
-            freeSize -= mapLen;
-          }
-        }
-        fclose(regionsFile);
-      }
-
-      nsPrintfCString path("mem/pmem/free/%s", name);
-      nsPrintfCString desc("Physical memory reserved for the \"%s\" pool and "
-                           "unavailable to the rest of the system, but not "
-                           "currently allocated.", name);
-      REPORT_WITH_CLEANUP(path, freeSize, desc, closedir(d));
-    }
-    closedir(d);
-    return NS_OK;
-  }
-
 #undef REPORT
 };
 
 NS_IMPL_ISUPPORTS1(SystemReporter, nsIMemoryReporter)
 
 // Keep this in sync with SystemReporter::ProcessSizeKind!
 const char* SystemReporter::kindPathSuffixes[] = {
     "anonymous/outside-brk",