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Subject[PATCH 4.4 3/7] sched/core, x86: Make struct thread_info arch specific again
From: Heiko Carstens <>

commit c8061485a0d7569a865a3cc3c63347b0f42b3765 upstream.

The following commit:

c65eacbe290b ("sched/core: Allow putting thread_info into task_struct")

... made 'struct thread_info' a generic struct with only a
single ::flags member, if CONFIG_THREAD_INFO_IN_TASK_STRUCT=y is

This change however seems to be quite x86 centric, since at least the
generic preemption code (asm-generic/preempt.h) assumes that struct
thread_info also has a preempt_count member, which apparently was not
true for x86.

We could add a bit more #ifdefs to solve this problem too, but it seems
to be much simpler to make struct thread_info arch specific
again. This also makes the conversion to THREAD_INFO_IN_TASK_STRUCT a
bit easier for architectures that have a couple of arch specific stuff
in their thread_info definition.

The arch specific stuff _could_ be moved to thread_struct. However
keeping them in thread_info makes it easier: accessing thread_info
members is simple, since it is at the beginning of the task_struct,
while the thread_struct is at the end. At least on s390 the offsets
needed to access members of the thread_struct (with task_struct as
base) are too large for various asm instructions. This is not a
problem when keeping these members within thread_info.

Signed-off-by: Heiko Carstens <>
Signed-off-by: Mark Rutland <>
Acked-by: Thomas Gleixner <>
Cc: Andrew Morton <>
Cc: Andy Lutomirski <>
Cc: Linus Torvalds <>
Cc: Peter Zijlstra <>
Signed-off-by: Ingo Molnar <>

[ zhangyi: skip defination of INIT_THREAD_INFO and struct thread_info ]

Signed-off-by: zhangyi (F) <>
include/linux/thread_info.h | 11 -----------
1 file changed, 11 deletions(-)

diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 2813de75a96e..897e835379d8 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -13,17 +13,6 @@
struct timespec;
struct compat_timespec;

-struct thread_info {
- u32 flags; /* low level flags */
-#define INIT_THREAD_INFO(tsk) \
-{ \
- .flags = 0, \
#define current_thread_info() ((struct thread_info *)current)
 \ /
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