[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>
diff --git a/include/asm-mips/cacheflush.h b/include/asm-mips/cacheflush.h
index e3c9925..0ddada3 100644
--- a/include/asm-mips/cacheflush.h
+++ b/include/asm-mips/cacheflush.h
@@ -17,6 +17,7 @@
*
* - flush_cache_all() flushes entire cache
* - flush_cache_mm(mm) flushes the specified mm context's cache lines
+ * - flush_cache_dup mm(mm) handles cache flushing when forking
* - flush_cache_page(mm, vmaddr, pfn) flushes a single page
* - flush_cache_range(vma, start, end) flushes a range of pages
* - flush_icache_range(start, end) flush a range of instructions
@@ -31,6 +32,7 @@
extern void (*flush_cache_all)(void);
extern void (*__flush_cache_all)(void);
extern void (*flush_cache_mm)(struct mm_struct *mm);
+#define flush_cache_dup_mm(mm) do { (void) (mm); } while (0)
extern void (*flush_cache_range)(struct vm_area_struct *vma,
unsigned long start, unsigned long end);
extern void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page, unsigned long pfn);