Introduce page coloring support to memory manager

xtoskrnl/mm/colors.cc

@@ -0,0 +1,95 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/mm/colors.cc
+ * DESCRIPTION:     Memory manager page coloring subsystem
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+#include <xtos.hh>
+
+
+/**
+ * Computes & initializes the system's page coloring.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+VOID
+MM::Colors::ComputePageColoring(VOID)
+{
+    UNIMPLEMENTED;
+
+    /* Compute L2 paging colors and mask */
+    PagingColors = MM_PAGING_COLORS;
+    PagingColorsMask = PagingColors - 1;
+}
+
+/**
+ * Retrieves a pointer to the color table for a specific page list and color.
+ *
+ * @param PageList
+ *        The page list type (e.g., FreePageList, ZeroedPageList).
+ *
+ * @param Color
+ *        Supplies the specific color index.
+ *
+ * @return This routine returns a pointer to the corresponding MMCOLOR_TABLES structure.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+PMMCOLOR_TABLES
+MM::Colors::GetFreePages(MMPAGELISTS PageList,
+                         ULONG Color)
+{
+    /* Return a pointer to the requested color table entry */
+    return &FreePages[PageList][Color];
+}
+
+/**
+ * Retrieves the next available color for page coloring.
+ *
+ * @return This routine returns the next color value, ensuring it stays within the valid color range.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+ULONG
+MM::Colors::GetNextColor()
+{
+    /* Increment the color counter and wrap it around using the mask */
+    return ((++PagingColors) & PagingColorsMask);
+}
+
+/**
+ * Retrieves the total number of page colors configured in the system.
+ *
+ * @return This routine returns the number of page colors.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+ULONG
+MM::Colors::GetPagingColors()
+{
+    /* Return the total number of page colors */
+    return PagingColors;
+}
+
+/**
+ * Retrieves the bitmask used for calculating a page's color.
+ *
+ * @return This routine returns the page color mask.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+ULONG
+MM::Colors::GetPagingColorsMask()
+{
+    /* Return the mask used for page coloring calculations */
+    return PagingColorsMask;
+}

xtoskrnl/mm/data.cc

@@ -9,6 +9,15 @@
 #include <xtos.hh>
 
 
+/* Array of free page lists segregated by cache color */
+PMMCOLOR_TABLES MM::Colors::FreePages[FreePageList + 1];
+
+/* Number of supported page colors */
+ULONG MM::Colors::PagingColors;
+
+/* Bitmask used to calculate the cache color index */
+ULONG MM::Colors::PagingColorsMask;
+
 /* Allocation descriptors dedicated for hardware layer */
 LOADER_MEMORY_DESCRIPTOR MM::HardwarePool::HardwareAllocationDescriptors[MM_HARDWARE_ALLOCATION_DESCRIPTORS];
 

xtoskrnl/mm/mmgr.cc

@@ -54,6 +54,9 @@ MM::Manager::InitializeMemoryManager(VOID)
         KE::Crash::Panic(0);
     }
 
+    /* Compute page colors to reduce CPU cache conflicts */
+    MM::Colors::ComputePageColoring();
+
     /* Compute allocation size for the PFN database */
     MM::Pfn::ComputePfnDatabaseSize();