[Zion] Track used vs free physical memory.

lib/glacier/container/linked_list.h

@@ -16,6 +16,23 @@ class LinkedList {
   bool empty() const { return size_ == 0; }
   uint64_t size() const { return size_; }
 
+  void PushFront(const T& item) {
+    ListItem* new_item = new ListItem{
+        .item = item,
+        .next = front_,
+    };
+    front_ = new_item;
+    size_++;
+  }
+  void PushFront(T&& item) {
+    ListItem* new_item = new ListItem{
+        .item = glcr::Move(item),
+        .next = front_,
+    };
+    front_ = new_item;
+    size_++;
+  }
+
   void PushBack(const T& item) {
     ListItem* new_item = new ListItem{
         .item = item,
@@ -42,7 +59,8 @@ class LinkedList {
     return ret;
   }
 
-  T& PeekFront() const { return front_->item; }
+  T& PeekFront() { return front_->item; }
+  const T& PeekFront() const { return front_->item; }
 
   struct ListItem {
     T item;

zion/interrupt/interrupt.cpp

@@ -7,6 +7,7 @@
 #include "interrupt/apic.h"
 #include "interrupt/apic_timer.h"
 #include "memory/kernel_heap.h"
+#include "memory/physical_memory.h"
 #include "scheduler/scheduler.h"
 
 #define IDT_INTERRUPT_GATE 0x8E
@@ -142,6 +143,7 @@ extern "C" void interrupt_apic_timer(InterruptFrame*) {
   if (cnt % 20 == 0) {
     if (cnt == 20) {
       KernelHeap::DumpDebugData();
+      phys_mem::DumpPhysicalMemoryUsage();
     }
     dbgln("timer: {}s", cnt * 50 / 1000);
   }

zion/memory/physical_memory.cpp

@@ -1,5 +1,7 @@
 #include "memory/physical_memory.h"
 
+#include <glacier/container/linked_list.h>
+
 #include "boot/boot_info.h"
 #include "debug/debug.h"
 
@@ -53,78 +55,89 @@ class PhysicalMemoryManager {
   }
 
   uint64_t AllocatePage() {
-    if (front_ == nullptr) {
+    if (memory_blocks.size() == 0) {
       panic("No available memory regions.");
     }
 
-    if (front_->num_pages == 0) {
-      panic("Bad state, empty memory block.");
+    while (memory_blocks.PeekFront().num_pages == 0) {
+      memory_blocks.PopFront();
     }
 
-    uint64_t page = front_->base;
-    front_->base += 0x1000;
-    front_->num_pages--;
-    if (front_->num_pages == 0) {
-      MemBlock* temp = front_;
-      front_ = front_->next;
-      delete temp;
+    MemBlock& block = memory_blocks.PeekFront();
+    uint64_t page = block.base;
+    block.base += 0x1000;
+    block.num_pages--;
+    if (block.num_pages == 0) {
+      memory_blocks.PopFront();
     }
 #if K_PHYS_DEBUG
     dbgln("Single {x}", page);
 #endif
+    allocated_pages_ += 1;
     return page;
   }
   uint64_t AllocateContinuous(uint64_t num_pages) {
-    if (front_ == nullptr) {
+    if (memory_blocks.size() == 0) {
       panic("No available memory regions.");
     }
 
-    if (front_->num_pages == 0) {
+    MemBlock& block = memory_blocks.PeekFront();
+    if (block.num_pages == 0) {
       panic("Bad state, empty memory block.");
     }
 
-    MemBlock* block = front_;
-    while (block != nullptr && block->num_pages < num_pages) {
-      dbgln("Skipping block of size {} seeking {}", block->num_pages,
-            num_pages);
-      block = block->next;
+    auto iter = memory_blocks.begin();
+    while (iter != memory_blocks.end() && iter->num_pages < num_pages) {
+      dbgln("Skipping block of size {} seeking {}", iter->num_pages, num_pages);
+      iter = iter.next();
     }
 
-    if (block == nullptr) {
+    if (iter == memory_blocks.end()) {
       panic("No memory regions to allocate");
     }
 
-    uint64_t page = front_->base;
-    front_->base += num_pages * 0x1000;
-    front_->num_pages -= num_pages;
-    if (front_->num_pages == 0) {
-      MemBlock* temp = front_;
-      front_ = front_->next;
-      delete temp;
-    }
+    uint64_t page = iter->base;
+    iter->base += num_pages * 0x1000;
+    iter->num_pages -= num_pages;
 #if K_PHYS_DEBUG
     dbgln("Continuous {x}:{}", page, num_pages);
 #endif
+    allocated_pages_ += num_pages;
     return page;
   }
-  void FreePage(uint64_t page) { AddMemoryRegion(page, 0x1000); }
+  void FreePage(uint64_t page) {
+    AddMemoryRegion(page, 0x1000);
+    allocated_pages_--;
+  }
+
+  uint64_t AllocatedPages() { return allocated_pages_; }
+
+  uint64_t AvailablePages() {
+    uint64_t available = 0;
+    for (auto iter = memory_blocks.begin(); iter != memory_blocks.end();
+         iter = iter.next()) {
+      available += iter->num_pages;
+    }
+    return available;
+  }
 
  private:
-  void AddMemoryRegion(uint64_t base, uint64_t size) {
-    MemBlock* block = new MemBlock{
-        .next = front_,
-        .base = base,
-        .num_pages = size >> 12,
-    };
-    front_ = block;
-  }
   struct MemBlock {
-    MemBlock* next = nullptr;
     uint64_t base = 0;
     uint64_t num_pages = 0;
   };
 
-  MemBlock* front_ = nullptr;
+  glcr::LinkedList<MemBlock> memory_blocks;
+
+  uint64_t allocated_pages_ = 0;
+
+  void AddMemoryRegion(uint64_t base, uint64_t size) {
+    MemBlock block{
+        .base = base,
+        .num_pages = size >> 12,
+    };
+    memory_blocks.PushFront(block);
+  }
 };
 
 static PhysicalMemoryManager* gPmm = nullptr;
@@ -220,4 +233,9 @@ uint64_t AllocateContinuous(uint64_t num_continuous) {
   return gPmm->AllocateContinuous(num_continuous);
 }
 
+void DumpPhysicalMemoryUsage() {
+  dbgln("Pages used: {} MiB, avail: {} MiB", gPmm->AllocatedPages() / 256,
+        gPmm->AvailablePages() / 256);
+}
+
 }  // namespace phys_mem

zion/memory/physical_memory.h

@@ -21,4 +21,6 @@ uint64_t AllocateAndZeroPage();
 uint64_t AllocateContinuous(uint64_t num_pages);
 void FreePage(uint64_t page);
 
+void DumpPhysicalMemoryUsage();
+
 }  // namespace phys_mem