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| author | Jeff Dike <jdike@addtoit.com> | 2005-09-03 15:57:36 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@evo.osdl.org> | 2005-09-05 00:06:22 -0700 |
| commit | c56004901fa5dcf55f92318f192ab3c0e87db2d1 (patch) | |
| tree | ac53ded16ab9886ce05d4b2d424dfed80dce9e57 /arch/um/sys-x86_64 | |
| parent | 77fa5adcda6d686d2f45a2b55dcb9a03e7d33fa1 (diff) | |
| download | op-kernel-dev-c56004901fa5dcf55f92318f192ab3c0e87db2d1.zip op-kernel-dev-c56004901fa5dcf55f92318f192ab3c0e87db2d1.tar.gz | |
[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>
Diffstat (limited to 'arch/um/sys-x86_64')
| -rw-r--r-- | arch/um/sys-x86_64/stub.S | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/um/sys-x86_64/stub.S b/arch/um/sys-x86_64/stub.S index 31c1492..957f2ef 100644 --- a/arch/um/sys-x86_64/stub.S +++ b/arch/um/sys-x86_64/stub.S @@ -13,3 +13,24 @@ syscall_stub: or %rcx, %rbx movq %rax, (%rbx) int3 + + .globl batch_syscall_stub +batch_syscall_stub: + movq $(UML_CONFIG_STUB_DATA >> 32), %rbx + salq $32, %rbx + movq $(UML_CONFIG_STUB_DATA & 0xffffffff), %rcx + or %rcx, %rbx + movq %rbx, %rsp +again: pop %rax + cmpq $0, %rax +jz done + pop %rdi + pop %rsi + pop %rdx + pop %r10 + pop %r8 + pop %r9 + syscall + mov %rax, (%rbx) + jmp again +done: int3 |
