[PATCH v9] um: Enable preemption in UML

[Johannes Berg]

>  arch/um/Kconfig                   |  2 +-
>  arch/um/include/asm/fpu/api.h     |  9 ++--
>  arch/um/include/asm/thread_info.h |  4 +-
>  arch/um/kernel/Makefile           |  4 ++
>  arch/um/kernel/fpu.c              | 71 +++++++++++++++++++++++++++++++
>  arch/um/kernel/irq.c              |  2 +
>  arch/um/kernel/tlb.c              | 13 ++++++

In addition to what Benjamin pointed out (FPU state is in the MM
process, so we probably don't care about save/restore), this also
doesn't build any more, at least it needs:

--- a/arch/x86/um/Makefile
+++ b/arch/x86/um/Makefile
@@ -31,7 +31,6 @@ obj-y += syscalls_64.o vdso/
 
 subarch-y = ../lib/csum-partial_64.o ../lib/memcpy_64.o \
        ../lib/memmove_64.o ../lib/memset_64.o
-subarch-$(CONFIG_PREEMPTION) += ../entry/thunk_64.o
 
 endif
 

git am also complained about the extra blank line at EOF here:

> +EXPORT_SYMBOL_GPL(kernel_fpu_end);
> +

johannes