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Kernel: Make the page table quickmaps per-CPU

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While the "regular" quickmap (used to temporarily map a physical page
at a known address for quick access) has been per-CPU for a while,
we also have the PD (page directory) and PT (page table) quickmaps
used by the memory management code to edit page tables. These have been
global, which meant that SMP systems had to keep fighting over them.

This patch makes *all* quickmaps per-CPU. We reserve virtual addresses
for up to 64 CPUs worth of quickmaps for now.

Note that all quickmaps are still protected by the MM lock, and we'll
have to fix that too, before seeing any real throughput improvements.
This commit is contained in:
Andreas Kling 2022-08-22 14:41:08 +02:00
parent 930dedfbd8
commit a838fdfd88
3 changed files with 21 additions and 34 deletions
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8
Kernel/Sections.h
View file

@ -17,9 +17,11 @@
#define KERNEL_PD_END (kernel_mapping_base + KERNEL_PD_SIZE)
#define KERNEL_PT1024_BASE (kernel_mapping_base + 0x3FE00000)
#define KERNEL_QUICKMAP_PT (KERNEL_PT1024_BASE + 0x6000)
#define KERNEL_QUICKMAP_PD (KERNEL_PT1024_BASE + 0x7000)
#define KERNEL_QUICKMAP_PER_CPU_BASE (KERNEL_PT1024_BASE + 0x8000)
#define KERNEL_MAX_CPU_COUNT 64
#define KERNEL_QUICKMAP_PT_PER_CPU_BASE (KERNEL_PT1024_BASE + (1 * KERNEL_MAX_CPU_COUNT * PAGE_SIZE))
#define KERNEL_QUICKMAP_PD_PER_CPU_BASE (KERNEL_PT1024_BASE + (2 * KERNEL_MAX_CPU_COUNT * PAGE_SIZE))
#define KERNEL_QUICKMAP_PER_CPU_BASE (KERNEL_PT1024_BASE + (3 * KERNEL_MAX_CPU_COUNT * PAGE_SIZE))
#define USER_RANGE_BASE 0x10000
#define USER_RANGE_CEILING (kernel_mapping_base - 0x2000000)