book

Understanding the Linux® Virtual Memory Manager

Name: Understanding the Linux® Virtual Memory Manager
Author: Mel Gorman
ISBN: 9780131453487

by Mel Gorman

April 2004

Intermediate to advanced

768 pages

15h 16m

English

Pearson

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Copyright
Dedication
Bruce Perens’ Open Source Series
About Prentice Hall Professional Technical Reference
Preface
The Intended AudienceBook OverviewWhat’s New in 2.6Companion CDTypographic ConventionsAcknowledgments
1. Introduction
1.1. Getting Started1.1.1. Configuration and Building1.1.2. Sources of Information1.2. Managing the Source1.2.1. Diff and Patch1.2.2. Basic Source Management With PatchSet1.3. Browsing the Code1.3.1. Analyzing Code Flow1.3.2. Simple Graph Generation1.4. Reading the Code1.5. Submitting Patches
2. Describing Physical Memory
2.1. Nodes2.2. Zones2.2.1. Zone Watermarks2.2.2. Calculating the Size of Zones2.2.3. Zone Wait Queue Table2.3. Zone Initialization2.4. Initializing mem_map2.5. Pages2.6. Mapping Pages to Zones2.7. High Memory2.8. What’s New in 2.6
3. Page Table Management
3.1. Describing the Page Directory3.2. Describing a Page Table Entry3.3. Using Page Table Entries3.4. Translating and Setting Page Table Entries3.5. Allocating and Freeing Page Tables3.6. Kernel Page Tables3.6.1. Bootstrapping3.6.2. Finalizing3.7. Mapping Addresses to a struct page3.7.1. Mapping Physical to Virtual Kernel Addresses3.7.2. Mapping struct pages to Physical Addresses3.8. Translation Lookaside Buffer (TLB)3.9. Level 1 CPU Cache Management3.10. What’s New in 2.6
4. Process Address Space
4.1. Linear Address Space4.2. Managing the Address Space4.3. Process Address Space Descriptor4.3.1. Allocating a Descriptor4.3.2. Initializing a Descriptor4.3.3. Destroying a Descriptor4.4. Memory Regions4.4.1. Memory Region Operations4.4.2. File/Device-Backed Memory Regions4.4.3. Creating a Memory Region4.4.4. Finding a Mapped Memory Region4.4.5. Finding a Free Memory Region4.4.6. Inserting a Memory Region4.4.7. Merging Contiguous Regions4.4.8. Remapping and Moving a Memory Region4.4.9. Locking a Memory Region4.4.10. Unlocking the Region4.4.11. Fixing Up Regions After Locking4.4.12. Deleting a Memory Region4.4.13. Deleting All Memory Regions4.5. Exception Handling4.6. Page Faulting4.6.1. Handling a Page Fault4.6.2. Demand Allocation4.6.3. Demand Paging4.6.4. COW Pages4.7. Copying to/from Userspace4.8. What’s New in 2.6
5. Boot Memory Allocator
5.1. Representing the Boot Map5.2. Initializing the Boot Memory Allocator5.3. Initializing bootmem_data5.4. Allocating Memory5.5. Freeing Memory5.6. Retiring the Boot Memory Allocator5.7. What’s New in 2.6
6. Physical Page Allocation
6.1. Managing Free Blocks6.2. Allocating Pages6.3. Free Pages6.4. Get Free Page (GFP) Flags6.5. Process Flags6.6. Avoiding Fragmentation6.7. What’s New in 2.6

7. Noncontiguous Memory Allocation
7.1. Describing Virtual Memory Areas7.2. Allocating a Noncontiguous Area7.3. Freeing a Noncontiguous Area7.4. What’s New in 2.6
8. Slab Allocator
8.1. Caches8.1.1. Cache Descriptor8.1.2. Cache Static Flags8.1.3. Cache Dynamic Flags8.1.4. Cache Allocation Flags8.1.5. Cache Coloring8.1.6. Cache Creation8.1.7. Cache Reaping8.1.8. Cache Shrinking8.1.9. Cache Destroying8.2. Slabs8.2.1. Storing the Slab Descriptor8.2.2. Slab Creation8.2.3. Tracking Free Objects8.2.4. Initializing the kmem_bufctl_t Array8.2.5. Finding the Next Free Object8.2.6. Updating kmem_bufctl_t8.2.7. Calculating the Number of Objects on a Slab8.2.8. Slab Destroying8.3. Objects8.3.1. Initializing Objects in a Slab8.3.2. Object Allocation8.3.3. Object Freeing8.4. Sizes Cache8.4.1. kmalloc()8.4.2. kfree()8.5. Per-CPU Object Cache8.5.1. Describing the Per-CPU Object Cache8.5.2. Adding/Removing Objects From the Per-CPU Cache8.5.3. Enabling Per-CPU Caches8.5.4. Updating Per-CPU Information8.5.5. Draining a Per-CPU Cache8.6. Slab Allocator Initialization8.7. Interfacing With the Buddy Allocator8.8. What’s New in 2.6
9. High Memory Management
9.1. Managing the PKMap Address Space9.2. Mapping High Memory Pages9.3. Unmapping Pages9.4. Mapping High Memory Pages Atomically9.5. Bounce Buffers9.5.1. Disk Buffering9.5.2. Creating Bounce Buffers9.5.3. Copying via Bounce Buffers9.6. Emergency Pools9.7. What’s New in 2.6
10. Page Frame Reclamation
10.1. Page Replacement Policy10.2. Page Cache10.2.1. Page Cache Hash Table10.2.2. Inode Queue10.2.3. Adding Pages to the Page Cache10.3. LRU Lists10.3.1. Refilling inactive_list10.3.2. Reclaiming Pages From the LRU Lists10.4. Shrinking All Caches10.5. Swapping Out Process Pages10.6. Pageout Daemon (kswapd)10.7. What’s New in 2.6
11. Swap Management
11.1. Describing the Swap Area11.2. Mapping Page Table Entries to Swap Entries11.3. Allocating a Swap Slot11.4. Swap Cache11.5. Reading Pages From Backing Storage11.6. Writing Pages to Backing Storage11.7. Reading/Writing Swap Area Blocks11.8. Activating a Swap Area11.9. Deactivating a Swap Area11.10. What’s New in 2.6
12. Shared Memory Virtual Filesystem
12.1. Initializing the Virtual Filesystem12.2. Using shmem Functions12.3. Creating Files in tmpfs12.4. Page Faulting Within a Virtual File12.4.1. Locating Swapped Pages12.4.2. Writing Pages to Swap12.5. File Operations in tmpfs12.6. Inode Operations in tmpfs12.7. Setting Up Shared Regions12.8. System V IPC12.9. What’s New in 2.6
13. Out of Memory Management
13.1. Checking Available Memory13.2. Determining OOM Status13.3. Selecting a Process13.4. Killing the Selected Process13.5. Is That It?13.6. What’s New in 2.6
14. The Final Word
A. Introduction
B. Describing Physical Memory
B.1. Initializing ZonesB.1.1. Function: setup_memory() (arch/i386/kernel/setup.c)B.1.2. Function: zone_sizes_init() (arch/i386/mm/init.c)B.1.3. Function: free_area_init() (mm/page_alloc.c)B.1.4. Function: free_area_init_node() (mm/numa.c)B.1.5. Function: free_area_init_core() (mm/page_alloc.c)B.1.6. Function: build_zonelists() (mm/page_alloc.c)B.2. Page OperationsB.2.1. Locking PagesB.2.1.1. Function: lock_page() (mm/filemap.c)B.2.1.2. Function: __lock_page() (mm/filemap.c)B.2.1.3. Function: sync_page() (mm/filemap.c)B.2.2. Unlocking PagesB.2.2.1. Function: unlock_page() (mm/filemap.c)B.2.3. Waiting on PagesB.2.3.1. Function: wait_on_page() (include/linux/pagemap.h)B.2.3.2. Function: ___wait_on_page() (mm/filemap.c)
C. Page Table Management
C.1. Page Table InitializationC.1.1. Function: paging_init() (arch/i386/mm/init.c)C.1.2. Function: pagetable_init() (arch/i386/mm/init.c)C.1.3. Function: fixrange_init() (arch/i386/mm/init.c)C.1.4. Function: kmap_init() (arch/i386/mm/init.c)C.2. Page Table WalkingC.2.1. Function: follow_page() (mm/memory.c)
D. Process Address Space
D.1. Process Memory DescriptorsD.1.1. Initializing a DescriptorD.1.2. Copying a DescriptorD.1.2.1. Function: copy_mm() (kernel/fork.c)D.1.2.2. Function: mm_init() (kernel/fork.c)D.1.3. Allocating a DescriptorD.1.3.1. Function: allocate_mm() (kernel/fork.c)D.1.3.2. Function: mm_alloc() (kernel/fork.c)D.1.4. Destroying a DescriptorD.1.4.1. Function: mmput() (kernel/fork.c)D.1.4.2. Function: mmdrop() (include/linux/sched.h)D.1.4.3. Function: __mmdrop() (kernel/fork.c)D.2. Creating Memory RegionsD.2.1. Creating a Memory RegionD.2.1.1. Function: do_mmap() (include/linux/mm.h)D.2.1.2. Function: do_mmap_pgoff() (mm/mmap.c)D.2.2. Inserting a Memory RegionD.2.2.1. Function: __insert_vm_struct() (mm/mmap.c)D.2.2.2. Function: find_vma_prepare() (mm/mmap.c)D.2.2.3. Function: vma_link() (mm/mmap.c)D.2.2.4. Function: __vma_link() (mm/mmap.c)D.2.2.5. Function: __vma_link_list() (mm/mmap.c)D.2.2.6. Function: __vma_link_rb() (mm/mmap.c)D.2.2.7. Function: __vma_link_file() (mm/mmap.c)D.2.3. Merging Contiguous RegionsD.2.3.1. Function: vma_merge() (mm/mmap.c)D.2.3.2. Function: can_vma_merge() (include/linux/mm.h)D.2.4. Remapping and Moving a Memory RegionD.2.4.1. Function: sys_mremap() (mm/mremap.c)D.2.4.2. Function: do_mremap() (mm/mremap.c)D.2.4.3. Function: move_vma() (mm/mremap.c)D.2.4.4. Function: make_pages_present() (mm/memory.c)D.2.4.5. Function: get_user_pages() (mm/memory.c)D.2.4.6. Function: move_page_tables() (mm/mremap.c)D.2.4.7. Function: move_one_page() (mm/mremap.c)D.2.4.8. Function: get_one_pte() (mm/mremap.c)D.2.4.9. Function: alloc_one_pte() (mm/mremap.c)D.2.4.10. Function: copy_one_pte() (mm/mremap.c)D.2.5. Deleting a Memory RegionD.2.5.1. Function: do_munmap() (mm/mmap.c)D.2.5.2. Function: unmap_fixup() (mm/mmap.c)D.2.6. Deleting All Memory RegionsD.2.6.1. Function: exit_mmap() (mm/mmap.c)D.2.6.2. Function: clear_page_tables() (mm/memory.c)D.2.6.3. Function: free_one_pgd() (mm/memory.c)D.2.6.4. Function: free_one_pmd() (mm/memory.c)D.3. Searching Memory RegionsD.3.1. Finding a Mapped Memory RegionD.3.1.1. Function: find_vma() (mm/mmap.c)D.3.1.2. Function: find_vma_prev() (mm/mmap.c)D.3.1.3. Function: find_vma_intersection() (include/linux/mm.h)D.3.2. Finding a Free Memory RegionD.3.2.1. Function: get_unmapped_area() (mm/mmap.c)D.3.2.2. Function: arch_get_unmapped_area() (mm/mmap.c)D.4. Locking and Unlocking Memory RegionsD.4.1. Locking a Memory RegionD.4.1.1. Function: sys_mlock() (mm/mlock.c)D.4.1.2. Function: sys_mlockall() (mm/mlock.c)D.4.1.3. Function: do_mlockall() (mm/mlock.c)D.4.1.4. Function: do_mlock() (mm/mlock.c)D.4.2. Unlocking the RegionD.4.2.1. Function: sys_munlock() (mm/mlock.c)D.4.2.2. Function: sys_munlockall() (mm/mlock.c)D.4.3. Fixing Up Regions After Locking/UnlockingD.4.3.1. Function: mlock_fixup() (mm/mlock.c)D.4.3.2. Function: mlock_fixup_all() (mm/mlock.c)D.4.3.3. Function: mlock_fixup_start() (mm/mlock.c)D.4.3.4. Function: mlock_fixup_end() (mm/mlock.c)D.4.3.5. Function: mlock_fixup_middle() (mm/mlock.c)D.5. Page FaultingD.5.1. x86 Page Fault HandlerD.5.1.1. Function: do_page_fault() (arch/i386/mm/fault.c)D.5.2. Expanding the StackD.5.2.1. Function: expand_stack() (include/linux/mm.h)D.5.3. Architecture-Independent Page Fault HandlerD.5.3.1. Function: handle_mm_fault() (mm/memory.c)D.5.3.2. Function: handle_pte_fault() (mm/memory.c)D.5.4. Demand AllocationD.5.4.1. Function: do_no_page() (mm/memory.c)D.5.4.2. Function: do_anonymous_page() (mm/memory.c)D.5.5. Demand PagingD.5.5.1. Function: do_swap_page() (mm/memory.c)D.5.5.2. Function: can_share_swap_page() (mm/swapfile.c)D.5.5.3. Function: exclusive_swap_page() (mm/swapfile.c)D.5.6. Copy On Write (COW) PagesD.5.6.1. Function: do_wp_page() (mm/memory.c)D.6. Page-Related Disk I/OD.6.1. Generic File ReadingD.6.1.1. Function: generic_file_read() (mm/filemap.c)D.6.1.2. Function: do_generic_file_read() (mm/filemap.c)D.6.1.3. Function: generic_file_readahead() (mm/filemap.c)D.6.2. Generic File mmap()D.6.2.1. Function: generic_file_mmap() (mm/filemap.c)D.6.3. Generic File TruncationD.6.3.1. Function: vmtruncate() (mm/memory.c)D.6.3.2. Function: vmtruncate_list() (mm/memory.c)D.6.3.3. Function: zap_page_range() (mm/memory.c)D.6.3.4. Function: zap_pmd_range() (mm/memory.c)D.6.3.5. Function: zap_pte_range() (mm/memory.c)D.6.3.6. Function: truncate_inode_pages() (mm/filemap.c)D.6.3.7. Function: truncate_list_pages() (mm/filemap.c)D.6.3.8. Function: truncate_complete_page() (mm/filemap.c)D.6.3.9. Function: do_flushpage() (mm/filemap.c)D.6.3.10. Function: truncate_partial_page() (mm/filemap.c)D.6.4. Reading Pages for the Page CacheD.6.4.1. Function: filemap_nopage() (mm/filemap.c)D.6.4.2. Function: page_cache_read() (mm/filemap.c)D.6.5. File Readahead for nopage()D.6.5.1. Function: nopage_sequential_readahead() (mm/filemap.c)D.6.5.2. Function: read_cluster_nonblocking() (mm/filemap.c)D.6.6. Swap-Related Read-AheadD.6.6.1. Function: swapin_readahead() (mm/memory.c)D.6.6.2. Function: valid_swaphandles() (mm/swapfile.c)
E. Boot Memory Allocator
E.1. Initializing the Boot Memory AllocatorE.1.1. Function: init_bootmem() (mm/bootmem.c)E.1.2. Function: init_bootmem_node() (mm/bootmem.c)E.1.3. Function: init_bootmem_core() (mm/bootmem.c)E.2. Allocating MemoryE.2.1. Reserving Large Regions of MemoryE.2.1.1. Function: reserve_bootmem() (mm/bootmem.c)E.2.1.2. Function: reserve_bootmem_node() (mm/bootmem.c)E.2.1.3. Function: reserve_bootmem_core() (mm/bootmem.c)E.2.2. Allocating Memory at Boot TimeE.2.2.1. Function: alloc_bootmem() (mm/bootmem.c)E.2.2.2. Function: __alloc_bootmem() (mm/bootmem.c)E.2.2.3. Function: alloc_bootmem_node() (mm/bootmem.c)E.2.2.4. Function: __alloc_bootmem_node() (mm/bootmem.c)E.2.2.5. Function: __alloc_bootmem_core() (mm/bootmem.c)E.3. Freeing MemoryE.3.1. Function: free_bootmem() (mm/bootmem.c)E.3.2. Function: free_bootmem_core() (mm/bootmem.c)E.4. Retiring the Boot Memory AllocatorE.4.1. Function: mem_init() (arch/i386/mm/init.c)E.4.2. Function: free_pages_init() (arch/i386/mm/init.c)E.4.3. Function: one_highpage_init() (arch/i386/mm/init.c)E.4.4. Function: free_all_bootmem() (mm/bootmem.c)E.4.5. Function: free_all_bootmem_core() (mm/bootmem.c)
F. Physical Page Allocation
F.1. Allocating PagesF.1.1. Function: alloc_pages() (include/linux/mm.h)F.1.2. Function: _alloc_pages() (mm/page_alloc.c)F.1.3. Function: __alloc_pages() (mm/page_alloc.c)F.1.4. Function: rmqueue() (mm/page_alloc.c)F.1.5. Function: expand() (mm/page_alloc.c)F.1.6. Function: balance_classzone() (mm/page_alloc.c)F.2. Allocation Helper FunctionsF.2.1. Function: alloc_page() (include/linux/mm.h)F.2.2. Function: __get_free_page() (include/linux/mm.h)F.2.3. Function: __get_free_pages() (mm/page_alloc.c)F.2.4. Function: __get_dma_pages() (include/linux/mm.h)F.2.5. Function: get_zeroed_page() (mm/page_alloc.c)F.3. Free PagesF.3.1. Function: __free_pages() (mm/page_alloc.c)F.3.2. Function: __free_pages_ok() (mm/page_alloc.c)F.4. Free Helper FunctionsF.4.1. Function: free_pages() (mm/page_alloc.c)F.4.2. Function: __free_page() (include/linux/mm.h)F.4.3. Function: free_page() (include/linux/mm.h)
G. Noncontiguous Memory Allocation
G.1. Allocating a Noncontiguous AreaG.1.1. Function: vmalloc() (include/linux/vmalloc.h)G.1.2. Function: __vmalloc() (mm/vmalloc.c)G.1.3. Function: get_vm_area() (mm/vmalloc.c)G.1.4. Function: vmalloc_area_pages() (mm/vmalloc.c)G.1.5. Function: __vmalloc_area_pages() (mm/vmalloc.c)G.1.6. Function: alloc_area_pmd() (mm/vmalloc.c)G.1.7. Function: alloc_area_pte() (mm/vmalloc.c)G.1.8. Function: vmap() (mm/vmalloc.c)G.2. Freeing a Noncontiguous AreaG.2.1. Function: vfree() (mm/vmalloc.c)G.2.2. Function: vmfree_area_pages() (mm/vmalloc.c)G.2.3. Function: free_area_pmd() (mm/vmalloc.c)G.2.4. Function: free_area_pte() (mm/vmalloc.c)
H. Slab Allocator
H.1. Cache ManipulationH.1.1. Cache CreationH.1.1.1. Function: kmem_cache_create() (mm/slab/c)H.1.2. Calculating the Number of Objects on a SlabH.1.2.1. Function: kmem_cache_estimate() (mm/slab.c)H.1.3. Cache ShrinkingH.1.3.1. Function: kmem_cache_shrink() (mm/slab.c)H.1.3.2. Function: __kmem_cache_shrink() (mm/slab.c)H.1.3.3. Function: __kmem_cache_shrink_locked() (mm/slab.c)H.1.4. Cache DestroyingH.1.4.1. Function: kmem_cache_destroy() (mm/slab.c)H.1.5. Cache ReapingH.1.5.1. Function: kmem_cache_reap() (mm/slab.c)H.2. SlabsH.2.1. Storing the Slab DescriptorH.2.1.1. Function: kmem_cache_slabmgmt() (mm/slab.c)H.2.1.2. Function: kmem_find_general_cachep() (mm/slab.c)H.2.2. Slab CreationH.2.2.1. Function: kmem_cache_grow() (mm/slab.c)H.2.3. Slab DestroyingH.2.3.1. Function: kmem_slab_destroy() (mm/slab.c)H.3. ObjectsH.3.1. Initializing Objects in a SlabH.3.1.1. Function: kmem_cache_init_objs() (mm/slab.c)H.3.2. Object AllocationH.3.2.1. Function: kmem_cache_alloc() (mm/slab.c)H.3.2.2. Function: __kmem_cache_alloc (UP Case)() (mm/slab.c)H.3.2.3. Function: __kmem_cache_alloc (SMP Case)() (mm/slab.c)H.3.2.4. Function: kmem_cache_alloc_head() (mm/slab.c)H.3.2.5. Function: kmem_cache_alloc_one() (mm/slab.c)H.3.2.6. Function: kmem_cache_alloc_one_tail() (mm/slab.c)H.3.2.7. Function: kmem_cache_alloc_batch() (mm/slab.c)H.3.3. Object FreeingH.3.3.1. Function: kmem_cache_free() (mm/slab.c)H.3.3.2. Function: __kmem_cache_free (UP Case)() (mm/slab.c)H.3.3.3. Function: __kmem_cache_free (SMP Case)() (mm/slab.c)H.3.3.4. Function: kmem_cache_free_one() (mm/slab.c)H.3.3.5. Function: free_block() (mm/slab.c)H.3.3.6. Function: __free_block() (mm/slab.c)H.4. Sizes CacheH.4.1. Initializing the Sizes CacheH.4.1.1. Function: kmem_cache_sizes_init() (mm/slab.c)H.4.2. kmalloc()H.4.2.1. Function: kmalloc() (mm/slab.c)H.4.3. kfree()H.4.3.1. Function: kfree() (mm/slab.c)H.5. Per-CPU Object CacheH.5.1. Enabling Per-CPU CachesH.5.1.1. Function: enable_all_cpucaches() (mm/slab.c)H.5.1.2. Function: enable_cpucache() (mm/slab.c)H.5.1.3. Function: kmem_tune_cpucache() (mm/slab.c)H.5.2. Updating Per-CPU InformationH.5.2.1. Function: smp_call_function_all_cpus() (mm/slab.c)H.5.2.2. Function: do_ccupdate_local() (mm/slab.c)H.5.3. Draining a Per-CPU CacheH.5.3.1. Function: drain_cpu_caches() (mm/slab.c)H.6. Slab Allocator InitializationH.6.1.1. Function: kmem_cache_init() (mm/slab.c)H.7. Interfacing with the Buddy AllocatorH.7.1.1. Function: kmem_getpages() (mm/slab.c)H.7.1.2. Function: kmem_freepages() (mm/slab.c)
I. High Memory Management
I.1. Mapping High Memory PagesI.1.1. Function: kmap() (include/asm-i386/highmem.c)I.1.2. Function: kmap_nonblock() (include/asm-i386/highmem.c)I.1.3. Function: __kmap() (include/asm-i386/highmem.h)I.1.4. Function: kmap_high() (mm/highmem.c)I.1.5. Function: map_new_virtual() (mm/highmem.c)I.1.6. Function: flush_all_zero_pkmaps() (mm/highmem.c)I.2. Mapping High Memory Pages AtomicallyI.2.1. Function: kmap_atomic() (include/asm-i386/highmem.h)I.3. Unmapping PagesI.3.1. Function: kunmap() (include/asm-i386/highmem.h)I.3.2. Function: kunmap_high() (mm/highmem.c)I.4. Unmapping High Memory Pages AtomicallyI.4.1. Function: kunmap_atomic() (include/asm-i386/highmem.h)I.5. Bounce BuffersI.5.1. Creating Bounce BuffersI.5.1.1. Function: create_bounce() (mm/highmem.c)I.5.1.2. Function: alloc_bounce_bh() (mm/highmem.c)I.5.1.3. Function: alloc_bounce_page() (mm/highmem.c)I.5.2. Copying Using Bounce BuffersI.5.2.1. Function: bounce_end_io_write() (mm/highmem.c)I.5.2.2. Function: bounce_end_io_read() (mm/highmem.c)I.5.2.3. Function: copy_from_high_bh() (mm/highmem.c)I.5.2.4. Function: copy_to_high_bh_irq() (mm/highmem.c)I.5.2.5. Function: bounce_end_io() (mm/highmem.c)I.6. Emergency PoolsI.6.1. Function: init_emergency_pool() (mm/highmem.c)
J. Page Frame Reclamation
J.1. Page Cache OperationsJ.1.1. Adding Pages to the Page CacheJ.1.1.1. Function: add_to_page_cache() (mm/filemap.c)J.1.1.2. Function: add_to_page_cache_unique() (mm/filemap.c)J.1.1.3. Function: __add_to_page_cache() (mm/filemap.c)J.1.1.4. Function: add_page_to_inode_queue() (mm/filemap.c)J.1.1.5. Function: add_page_to_hash_queue() (mm/filemap.c)J.1.2. Deleting Pages From the Page CacheJ.1.2.1. Function: remove_inode_page() (mm/filemap.c)J.1.2.2. Function: __remove_inode_page() (mm/filemap.c)J.1.2.3. Function:remove_page_from_inode_queue() (mm/filemap.c)J.1.2.4. Function: remove_page_from_hash_queue() (mm/filemap.c)J.1.3. Acquiring/Releasing Page Cache PagesJ.1.3.1. Function: page_cache_get() (include/linux/pagemap.h)J.1.3.2. Function: page_cache_release() (include/linux/pagemap.h)J.1.4. Searching the Page CacheJ.1.4.1. Function: find_get_page() (include/linux/pagemap.h)J.1.4.2. Function: __find_get_page() (mm/filemap.c)J.1.4.3. Function: __find_page_nolock() (mm/filemap.c)J.1.4.4. Function: find_lock_page() (include/linux/pagemap.h)J.1.4.5. Function: __find_lock_page() (mm/filemap.c)J.1.4.6. Function: __find_lock_page_helper() (mm/filemap.c)J.2. LRU List OperationsJ.2.1. Adding Pages to the LRU ListsJ.2.1.1. Function: lru_cache_add() (mm/swap.c)J.2.1.2. Function: add_page_to_active_list() (include/linux/swap.h)J.2.1.3. Function: add_page_to_inactive_list() (include/linux/swap.h)J.2.2. Deleting Pages From the LRU ListsJ.2.2.1. Function: lru_cache_del() (mm/swap.c)J.2.2.2. Function: __lru_cache_del() (mm/swap.c)J.2.2.3. Function: del_page_from_active_list() (include/linux/swap.h)J.2.2.4. Function: del_page_from_inactive_list() (include/linux/swap.h)J.2.3. Activating PagesJ.2.3.1. Function: mark_page_accessed() (mm/filemap.c)J.2.3.2. Function: activate_lock() (mm/swap.c)J.2.3.3. Function: activate_page_nolock() (mm/swap.c)J.3. Refilling inactive_listJ.3.1. Function: refill_inactive() (mm/vmscan.c)J.4. Reclaiming Pages From the LRU ListsJ.4.1. Function: shrink_cache() (mm/vmscan.c)J.5. Shrinking All CachesJ.5.1. Function: shrink_caches() (mm/vmscan.c)J.5.2. Function: try_to_free_pages() (mm/vmscan.c)J.5.3. Function: try_to_free_pages_zone() (mm/vmscan.c)J.6. Swapping Out Process PagesJ.6.1. Function: swap_out() (mm/vmscan.c)J.6.2. Function: swap_out_mm() (mm/vmscan.c)J.6.3. Function: swap_out_vma() (mm/vmscan.c)J.6.4. Function: swap_out_pgd() (mm/vmscan.c)J.6.5. Function: swap_out_pmd() (mm/vmscan.c)J.6.6. Function: try_to_swap_out() (mm/vmscan.c)J.7. Page Swap DaemonJ.7.1. Initializing kswapdJ.7.1.1. Function: kswapd_init() (mm/vmscan.c)J.7.2. kswapd DaemonJ.7.2.1. Function: kswapd() (mm/vmscan.c)J.7.2.2. Function: kswapd_can_sleep() (mm/vmscan.c)J.7.2.3. Function: kswapd_can_sleep_pgdat() (mm/vmscan.c)J.7.2.4. Function: kswapd_balance() (mm/vmscan.c)J.7.2.5. Function: kswapd_balance_pgdat() (mm/vmscan.c)
K. Swap Management
K.1. Scanning for Free EntriesK.1.1. Function: get_swap_page() (mm/swapfile.c)K.1.2. Function: scan_swap_map() (mm/swapfile.c)K.2. Swap CacheK.2.1. Adding Pages to the Swap CacheK.2.1.1. Function: add_to_swap_cache() (mm/swap_state.c)K.2.1.2. Function: swap_duplicate() (mm/swapfile.c)K.2.2. Deleting Pages From the Swap CacheK.2.2.1. Function: swap_free() (mm/swapfile.c)K.2.2.2. Function: swap_entry_free() (mm/swapfile.c)K.2.3. Acquiring/Releasing Swap Cache PagesK.2.3.1. Function: swap_info_get() (mm/swapfile.c)K.2.3.2. Function: swap_info_put() (mm/swapfile.c)K.2.4. Searching the Swap CacheK.2.4.1. Function: lookup_swap_cache() (mm/swap_state.c)K.3. Swap Area I/OK.3.1. Reading Backing StorageK.3.1.1. Function: read_swap_cache_async() (mm/swap_state.c)K.3.2. Writing Backing StorageK.3.2.1. Function: swap_writepage() (mm/swap_state.c)K.3.2.2. Function: remove_exclusive_swap_page() (mm/swapfile.c)K.3.2.3. Function: free_swap_and_cache() (mm/swapfile.c)K.3.3. Block I/OK.3.3.1. Function: rw_swap_page() (mm/page_io.c)K.3.3.2. Function: rw_swap_page_base() (mm/page_io.c)K.3.3.3. Function: get_swaphandle_info() (mm/swapfile.c)K.4. Activating a Swap AreaK.4.1. Function: sys_swapon() (mm/swapfile.c)K.4.2. Function: swap_setup() (mm/swap.c)K.5. Deactivating a Swap AreaK.5.1. Function: sys_swapoff() (mm/swapfile.c)K.5.2. Function: try_to_unuse() (mm/swapfile.c)K.5.3. Function: unuse_process() (mm/swapfile.c)K.5.4. Function: unuse_vma() (mm/swapfile.c)K.5.5. Function: unuse_pgd() (mm/swapfile.c)K.5.6. Function: unuse_pmd() (mm/swapfile.c)K.5.7. Function: unuse_pte() (mm/swapfile.c)
L. Shared Memory Virtual Filesystem
L.1. Initializing shmfsL.1.1. Function: init_tmpfs() (mm/shmem.c)L.1.2. Function: shmem_read_super() (mm/shmem.c)L.1.3. Function: shmem_set_size() (mm/shmem.c)L.2. Creating Files in tmpfsL.2.1. Function: shmem_create() (mm/shmem.c)L.2.2. Function: shmem_mknod() (mm/shmem.c)L.2.3. Function: shmem_get_inode() (mm/shmem.c)L.3. File Operations in tmpfsL.3.1. Memory MappingL.3.1.1. Function: shmem_mmap() (mm/shmem.c)L.3.2. Reading FilesL.3.2.1. Function: shmem_file_read() (mm/shmem.c)L.3.2.2. Function: do_shmem_file_read() (mm/shmem.c)L.3.2.3. Function: file_read_actor() (mm/filemap.c)L.3.3. WritingL.3.3.1. Function: shmem_file_write() (mm/shmem.c)L.3.4. Symbolic LinkingL.3.4.1. Function: shmem_symlink() (mm/shmem.c)L.3.4.2. Function: shmem_readlink_inline() (mm/shmem.c)L.3.4.3. Function: shmem_follow_link_inline() (mm/shmem.c)L.3.4.4. Function: shmem_readlink() (mm/shmem.c)L.3.5. SynchronizingL.3.5.1. Function: shmem_sync_file() (mm/shmem.c)L.4. Inode Operations in tmpfsL.4.1. TruncatingL.4.1.1. Function: shmem_truncate() (mm/shmem.c)L.4.1.2. Function: shmem_truncate_indirect() (mm/shmem.c)L.4.1.3. Function: shmem_truncate_direct() (mm/shmem.c)L.4.1.4. Function: shmem_free_swp() (mm/shmem.c)L.4.2. LinkingL.4.2.1. Function: shmem_link() (mm/shmem.c)L.4.3. UnlinkingL.4.3.1. Function: shmem_unlink() (mm/shmem.c)L.4.4. Making DirectoriesL.4.4.1. Function: shmem_mkdir() (mm/shmem.c)L.4.5. Removing DirectoriesL.4.5.1. Function: shmem_rmdir() (mm/shmem.c)L.4.5.2. Function: shmem_empty() (mm/shmem.c)L.4.5.3. Function: shmem_positive() (mm/shmem.c)L.5. Page Faulting Within a Virtual FileL.5.1. Reading Pages During Page FaultL.5.1.1. Function: shmem_nopage() (mm/shmem.c)L.5.1.2. Function: shmem_getpage() (mm/shmem.c)L.5.2. Locating Swapped PagesL.5.2.1. Function: shmem_alloc_entry() (mm/shmem.c)L.5.2.2. Function: shmem_swp_entry() (mm/shmem.c)L.6. Swap Space InteractionL.6.1. Function: shmem_writepage()(mm/shmem.c)L.6.2. Function: shmem_unuse()(mm/shmem.c)L.6.3. Function: shmem_unuse_inode()(mm/shmem.c)L.6.4. Function: shmem_find_swp()(mm/shmem.c)L.7. Setting Up Shared RegionsL.7.1. Function: shmem_zero_setup()(mm/shmem.c)L.7.2. Function: shmem_file_setup()(mm/shmem.c)L.8. System V IPCL.8.1. Creating a SYSV Shared RegionL.8.1.1. Function: sys_shmget() (ipc/shm.c)L.8.1.2. Function: newseg() (ipc/shm.c)L.8.2. Attaching a SYSV Shared RegionL.8.2.1. Function: sys_shmat() (ipc/shm.c)
M. Out of Memory Management
M.1. Determining Available MemoryM.1.1. Function: vm_enough_memory() (mm/mmap.c)M.2. Detecting and Recovering From OOMM.2.1. Function: out_of_memory() (mm/oom_kill.c)M.2.2. Function: oom_kill() (mm/oom_kill.c)M.2.3. Function: select_bad_process() (mm/oom_kill.c)M.2.4. Function: badness() (mm/oom_kill.c)M.2.5. Function: oom_kill_task() (mm/oom_kill.c)
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Content preview from Understanding the Linux® Virtual Memory Manager

Chapter 8. Slab Allocator

In this chapter, the general-purpose allocator is described. It is a slab allocator that is very similar in many respects to the general kernel allocator used in Solaris [MM01]. Linux’s implementation is heavily based on the first slab allocator paper by Bonwick [Bon94] with many improvements that bear a close resemblance to those described in his later paper [BA01]. I begin with a quick overview of the allocator, followed by a description of the different structures used before giving an in-depth tour of each task the allocator is responsible for.

The basic idea behind the slab allocator is to have caches of commonly used objects kept in an initialized state available for use by the kernel. Without an object-based allocator, ...

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Understanding the Linux® Virtual Memory Manager

by Mel Gorman

Chapter 8. Slab Allocator

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