include/linux/mm_types_task.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_MM_TYPES_TASK_H
   3 #define _LINUX_MM_TYPES_TASK_H
   4
   5 /*
   6  * Here are the definitions of the MM data types that are embedded in 'struct task_struct'.
   7  *
   8  * (These are defined separately to decouple sched.h from mm_types.h as much as possible.)
   9  */
  10
  11 #include <linux/types.h>
  12 #include <linux/threads.h>
  13 #include <linux/atomic.h>
  14 #include <linux/cpumask.h>
  15
  16 #include <asm/page.h>
  17
  18 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
  19 #include <asm/tlbbatch.h>
  20 #endif
  21
  22 #define USE_SPLIT_PTE_PTLOCKS   (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
  23 #define USE_SPLIT_PMD_PTLOCKS   (USE_SPLIT_PTE_PTLOCKS && \
  24                 IS_ENABLED(CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK))
  25 #define ALLOC_SPLIT_PTLOCKS     (SPINLOCK_SIZE > BITS_PER_LONG/8)
  26
  27 /*
  28  * The per task VMA cache array:
  29  */
  30 #define VMACACHE_BITS 2
  31 #define VMACACHE_SIZE (1U << VMACACHE_BITS)
  32 #define VMACACHE_MASK (VMACACHE_SIZE - 1)
  33
  34 struct vmacache {
  35         u64 seqnum;
  36         struct vm_area_struct *vmas[VMACACHE_SIZE];
  37 };
  38
  39 /*
  40  * When updating this, please also update struct resident_page_types[] in
  41  * kernel/fork.c
  42  */
  43 enum {
  44         MM_FILEPAGES,   /* Resident file mapping pages */
  45         MM_ANONPAGES,   /* Resident anonymous pages */
  46         MM_SWAPENTS,    /* Anonymous swap entries */
  47         MM_SHMEMPAGES,  /* Resident shared memory pages */
  48         NR_MM_COUNTERS
  49 };
  50
  51 #if USE_SPLIT_PTE_PTLOCKS && defined(CONFIG_MMU)
  52 #define SPLIT_RSS_COUNTING
  53 /* per-thread cached information, */
  54 struct task_rss_stat {
  55         int events;     /* for synchronization threshold */
  56         int count[NR_MM_COUNTERS];
  57 };
  58 #endif /* USE_SPLIT_PTE_PTLOCKS */
  59
  60 struct mm_rss_stat {
  61         atomic_long_t count[NR_MM_COUNTERS];
  62 };
  63
  64 struct page_frag {
  65         struct page *page;
  66 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
  67         __u32 offset;
  68         __u32 size;
  69 #else
  70         __u16 offset;
  71         __u16 size;
  72 #endif
  73 };
  74
  75 /* Track pages that require TLB flushes */
  76 struct tlbflush_unmap_batch {
  77 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
  78         /*
  79          * The arch code makes the following promise: generic code can modify a
  80          * PTE, then call arch_tlbbatch_add_mm() (which internally provides all
  81          * needed barriers), then call arch_tlbbatch_flush(), and the entries
  82          * will be flushed on all CPUs by the time that arch_tlbbatch_flush()
  83          * returns.
  84          */
  85         struct arch_tlbflush_unmap_batch arch;
  86
  87         /* True if a flush is needed. */
  88         bool flush_required;
  89
  90         /*
  91          * If true then the PTE was dirty when unmapped. The entry must be
  92          * flushed before IO is initiated or a stale TLB entry potentially
  93          * allows an update without redirtying the page.
  94          */
  95         bool writable;
  96 #endif
  97 };
  98
  99 #endif /* _LINUX_MM_TYPES_TASK_H */