diff options
Diffstat (limited to 'Documentation/cachetlb.txt')
-rw-r--r-- | Documentation/cachetlb.txt | 27 |
1 files changed, 2 insertions, 25 deletions
diff --git a/Documentation/cachetlb.txt b/Documentation/cachetlb.txt index 552cabac0608..da42ab414c48 100644 --- a/Documentation/cachetlb.txt +++ b/Documentation/cachetlb.txt | |||
@@ -87,30 +87,7 @@ changes occur: | |||
87 | 87 | ||
88 | This is used primarily during fault processing. | 88 | This is used primarily during fault processing. |
89 | 89 | ||
90 | 5) void flush_tlb_pgtables(struct mm_struct *mm, | 90 | 5) void update_mmu_cache(struct vm_area_struct *vma, |
91 | unsigned long start, unsigned long end) | ||
92 | |||
93 | The software page tables for address space 'mm' for virtual | ||
94 | addresses in the range 'start' to 'end-1' are being torn down. | ||
95 | |||
96 | Some platforms cache the lowest level of the software page tables | ||
97 | in a linear virtually mapped array, to make TLB miss processing | ||
98 | more efficient. On such platforms, since the TLB is caching the | ||
99 | software page table structure, it needs to be flushed when parts | ||
100 | of the software page table tree are unlinked/freed. | ||
101 | |||
102 | Sparc64 is one example of a platform which does this. | ||
103 | |||
104 | Usually, when munmap()'ing an area of user virtual address | ||
105 | space, the kernel leaves the page table parts around and just | ||
106 | marks the individual pte's as invalid. However, if very large | ||
107 | portions of the address space are unmapped, the kernel frees up | ||
108 | those portions of the software page tables to prevent potential | ||
109 | excessive kernel memory usage caused by erratic mmap/mmunmap | ||
110 | sequences. It is at these times that flush_tlb_pgtables will | ||
111 | be invoked. | ||
112 | |||
113 | 6) void update_mmu_cache(struct vm_area_struct *vma, | ||
114 | unsigned long address, pte_t pte) | 91 | unsigned long address, pte_t pte) |
115 | 92 | ||
116 | At the end of every page fault, this routine is invoked to | 93 | At the end of every page fault, this routine is invoked to |
@@ -123,7 +100,7 @@ changes occur: | |||
123 | translations for software managed TLB configurations. | 100 | translations for software managed TLB configurations. |
124 | The sparc64 port currently does this. | 101 | The sparc64 port currently does this. |
125 | 102 | ||
126 | 7) void tlb_migrate_finish(struct mm_struct *mm) | 103 | 6) void tlb_migrate_finish(struct mm_struct *mm) |
127 | 104 | ||
128 | This interface is called at the end of an explicit | 105 | This interface is called at the end of an explicit |
129 | process migration. This interface provides a hook | 106 | process migration. This interface provides a hook |