From ad061b4322afd211f60403dd780c5f95da71f42e Mon Sep 17 00:00:00 2001
From: Beq <beqjanus@gmail.com>
Date: Sun, 23 Jun 2024 14:20:23 +0100
Subject: [PATCH] WiP to realign the physical ram detection across platforms

---
 indra/llcommon/llmemory.cpp | 62 +++++++++++++++++++++++++++----------
 1 file changed, 46 insertions(+), 16 deletions(-)

diff --git a/indra/llcommon/llmemory.cpp b/indra/llcommon/llmemory.cpp
index cf5ead718d..eab87df300 100644
--- a/indra/llcommon/llmemory.cpp
+++ b/indra/llcommon/llmemory.cpp
@@ -39,6 +39,7 @@
 #elif LL_LINUX
 # include <unistd.h>
 # include <sys/resource.h>
+# inlcude <sys/sysinfo.h>
 #endif
 
 #include "llmemory.h"
@@ -85,6 +86,7 @@ void LLMemory::initMaxHeapSizeGB(F32Gigabytes max_heap_size)
 void LLMemory::updateMemoryInfo()
 {
     LL_PROFILE_ZONE_SCOPED
+    U32Kilobytes avail_phys; // <FS:Beq/> align MemInfo across platforms
 #if LL_WINDOWS
     PROCESS_MEMORY_COUNTERS counters;
 
@@ -98,20 +100,22 @@ void LLMemory::updateMemoryInfo()
     sample(sAllocatedMem, sAllocatedMemInKB);
     sAllocatedPageSizeInKB = U32Kilobytes::convert(U64Bytes(counters.PagefileUsage));
     sample(sVirtualMem, sAllocatedPageSizeInKB);
+    // <FS:Beq> align MemInfo across platforms
+    // U32Kilobytes avail_phys, avail_virtual;
+    // LLMemoryInfo::getAvailableMemoryKB(avail_phys, avail_virtual) ;
+    // sMaxPhysicalMemInKB = llmin(avail_phys + sAllocatedMemInKB, sMaxHeapSizeInKB);
 
-    U32Kilobytes avail_phys, avail_virtual;
+    // if(sMaxPhysicalMemInKB > sAllocatedMemInKB)
+    // {
+    //     sAvailPhysicalMemInKB = sMaxPhysicalMemInKB - sAllocatedMemInKB ;
+    // }
+    // else
+    // {
+    //     sAvailPhysicalMemInKB = U32Kilobytes(0);
+    // }
+    U32Kilobytes avail_virtual; 
     LLMemoryInfo::getAvailableMemoryKB(avail_phys, avail_virtual) ;
-    sMaxPhysicalMemInKB = llmin(avail_phys + sAllocatedMemInKB, sMaxHeapSizeInKB);
-
-    if(sMaxPhysicalMemInKB > sAllocatedMemInKB)
-    {
-        sAvailPhysicalMemInKB = sMaxPhysicalMemInKB - sAllocatedMemInKB ;
-    }
-    else
-    {
-        sAvailPhysicalMemInKB = U32Kilobytes(0);
-    }
-
+    // </FS:Beq>
 #elif defined(LL_DARWIN)
     task_vm_info info;
     mach_msg_type_number_t  infoCount = TASK_VM_INFO_COUNT;
@@ -147,21 +151,47 @@ void LLMemory::updateMemoryInfo()
     if (result == KERN_SUCCESS) {
         // This is what Chrome reports as 'the "Physical Memory Free" value reported by the Memory Monitor in Instruments.'
         // Note though that inactive pages are not included here and not yet free, but could become so under memory pressure.
-        sAvailPhysicalMemInKB = U32Bytes(vmstat.free_count * page_size);
-        sMaxPhysicalMemInKB = LLMemoryInfo::getHardwareMemSize();
-      }
+        // <FS:Beq> align MemInfo across platforms
+        // sAvailPhysicalMemInKB = U32Bytes(vmstat.free_count * page_size);
+        // sMaxPhysicalMemInKB = LLMemoryInfo::getHardwareMemSize();
+        avail_phys = U32Bytes(vmstat.free_count * page_size);
+        sMaxHeapSizeInKB = LLMemoryInfo::getHardwareMemSize();
+        // </FS:Beq>
+    }
     else
     {
         LL_WARNS() << "task_info failed" << LL_ENDL;
     }
-
+    // <FS:Beq> align MemInfo across platforms
+#elif defined(LL_LINUX)
+    // Use sysinfo() to get the total physical memory.
+    struct sysinfo info;
+    sysinfo(&info);
+    sMaxHeapSizeInKB = U32Kilobytes::convert(info.totalram); // Total RAM in system
+    avail_phys = U32Kilobytes::convert(info.freeram); // Total Free RAM in system
+    sAllocatedMemInKB = U64Bytes(LLMemory::getCurrentRSS()); // represents the RAM allocated by this process only (inline with the windows implementation)
+    // </FS:Beq>
 #else
     //not valid for other systems for now.
+    LL_WARNS() << "LLMemory::updateMemoryInfo() not implemented for this platform." << LL_ENDL;
     sAllocatedMemInKB = U64Bytes(LLMemory::getCurrentRSS());
     sMaxPhysicalMemInKB = U64Bytes(U32_MAX);
     sAvailPhysicalMemInKB = U64Bytes(U32_MAX);
 #endif
+    // <FS:Beq> align MemInfo across platforms
+    sample(sAllocatedMem, sAllocatedMemInKB);
+    // sMaxPhysicalMem - max this process can use = the lesser of (what we already have + what's available) or MaxHeap
+    sMaxPhysicalMemInKB = llmin(avail_phys + sAllocatedMemInKB, sMaxHeapSizeInKB); 
 
+    if(sMaxPhysicalMemInKB > sAllocatedMemInKB)
+    {
+        sAvailPhysicalMemInKB = sMaxPhysicalMemInKB - sAllocatedMemInKB ;
+    }
+    else
+    {
+        sAvailPhysicalMemInKB = U32Kilobytes(0);
+    }
+    // </FS:Beq>
     return ;
 }