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| author | Ralf Baechle <ralf@linux-mips.org> | 2006-12-12 17:14:57 +0000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-13 09:27:08 -0800 |
| commit | ec8c0446b6e2b67b5c8813eb517f4bf00efa99a9 (patch) | |
| tree | e7c12d7c486c958a5e38888b41cfcd6a558f1aff /Documentation/cachetlb.txt | |
| parent | bcd022801ee514e28c32837f0b3ce18c775f1a7b (diff) | |
| download | lwn-ec8c0446b6e2b67b5c8813eb517f4bf00efa99a9.tar.gz lwn-ec8c0446b6e2b67b5c8813eb517f4bf00efa99a9.zip | |
[PATCH] Optimize D-cache alias handling on fork
Virtually index, physically tagged cache architectures can get away
without cache flushing when forking. This patch adds a new cache
flushing function flush_cache_dup_mm(struct mm_struct *) which for the
moment I've implemented to do the same thing on all architectures
except on MIPS where it's a no-op.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'Documentation/cachetlb.txt')
| -rw-r--r-- | Documentation/cachetlb.txt | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/Documentation/cachetlb.txt b/Documentation/cachetlb.txt index 53245c429f7d..73e794f0ff09 100644 --- a/Documentation/cachetlb.txt +++ b/Documentation/cachetlb.txt @@ -179,10 +179,21 @@ Here are the routines, one by one: lines associated with 'mm'. This interface is used to handle whole address space - page table operations such as what happens during - fork, exit, and exec. + page table operations such as what happens during exit and exec. + +2) void flush_cache_dup_mm(struct mm_struct *mm) + + This interface flushes an entire user address space from + the caches. That is, after running, there will be no cache + lines associated with 'mm'. + + This interface is used to handle whole address space + page table operations such as what happens during fork. + + This option is separate from flush_cache_mm to allow some + optimizations for VIPT caches. -2) void flush_cache_range(struct vm_area_struct *vma, +3) void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) Here we are flushing a specific range of (user) virtual @@ -199,7 +210,7 @@ Here are the routines, one by one: call flush_cache_page (see below) for each entry which may be modified. -3) void flush_cache_page(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn) +4) void flush_cache_page(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn) This time we need to remove a PAGE_SIZE sized range from the cache. The 'vma' is the backing structure used by @@ -220,7 +231,7 @@ Here are the routines, one by one: This is used primarily during fault processing. -4) void flush_cache_kmaps(void) +5) void flush_cache_kmaps(void) This routine need only be implemented if the platform utilizes highmem. It will be called right before all of the kmaps @@ -232,7 +243,7 @@ Here are the routines, one by one: This routing should be implemented in asm/highmem.h -5) void flush_cache_vmap(unsigned long start, unsigned long end) +6) void flush_cache_vmap(unsigned long start, unsigned long end) void flush_cache_vunmap(unsigned long start, unsigned long end) Here in these two interfaces we are flushing a specific range |