[PATCH] uml: TLB operation batching
This adds VM op batching to skas0. Rather than having a context switch to and
from the userspace stub for each address space change, we write a number of
operations to the stub data page and invoke a different stub which loops over
them and executes them all in one go.
The operations are stored as [ system call number, arg1, arg2, ... ] tuples.
The set is terminated by a system call number of 0. Single operations, i.e.
page faults, are handled in the old way, since that is slightly more
efficient.
For a kernel build, a minority (~1/4) of the operations are part of a set.
These sets averaged ~100 in length, so for this quarter, the context switching
overhead is greatly reduced.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/include/tlb.h b/arch/um/include/tlb.h
index c6f9628..2deefb9 100644
--- a/arch/um/include/tlb.h
+++ b/arch/um/include/tlb.h
@@ -9,7 +9,7 @@
#include "um_mmu.h"
struct host_vm_op {
- enum { MMAP, MUNMAP, MPROTECT } type;
+ enum { NONE, MMAP, MUNMAP, MPROTECT } type;
union {
struct {
unsigned long addr;
@@ -38,24 +38,10 @@
extern void force_flush_all(void);
extern void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
unsigned long end_addr, int force,
- void (*do_ops)(union mm_context *,
- struct host_vm_op *, int));
+ void *(*do_ops)(union mm_context *,
+ struct host_vm_op *, int, int,
+ void *));
extern int flush_tlb_kernel_range_common(unsigned long start,
unsigned long end);
-extern int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
- int r, int w, int x, struct host_vm_op *ops, int index,
- int last_filled, union mm_context *mmu,
- void (*do_ops)(union mm_context *, struct host_vm_op *,
- int));
-extern int add_munmap(unsigned long addr, unsigned long len,
- struct host_vm_op *ops, int index, int last_filled,
- union mm_context *mmu,
- void (*do_ops)(union mm_context *, struct host_vm_op *,
- int));
-extern int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
- int x, struct host_vm_op *ops, int index,
- int last_filled, union mm_context *mmu,
- void (*do_ops)(union mm_context *, struct host_vm_op *,
- int));
#endif