From ec8c0446b6e2b67b5c8813eb517f4bf00efa99a9 Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Tue, 12 Dec 2006 17:14:57 +0000 Subject: [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 Signed-off-by: Linus Torvalds --- Documentation/cachetlb.txt | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) (limited to 'Documentation') diff --git a/Documentation/cachetlb.txt b/Documentation/cachetlb.txt index 53245c429f7..73e794f0ff0 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 -- cgit v1.2.2