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| author |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-10-25 12:21:44 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-11-11 16:37:40 +0100 |
| commit | c360192bf4a8dc72f102dd6a4e1bf8bd0b404cfa (patch) | |
| tree | c54104bae43978dfe31e6fc2c9a4d996218379fd /arch/s390/include/asm/thread_info.h | |
| parent | s390/bitops: use atomic primitives for bitops (diff) | |
| download | linux-dev-c360192bf4a8dc72f102dd6a4e1bf8bd0b404cfa.tar.xz linux-dev-c360192bf4a8dc72f102dd6a4e1bf8bd0b404cfa.zip | |
s390/preempt: move preempt_count to the lowcore
Convert s390 to use a field in the struct lowcore for the CPU
preemption count. It is a bit cheaper to access a lowcore field
compared to a thread_info variable and it removes the depencency
on a task related structure.
bloat-o-meter on the vmlinux image for the default configuration
(CONFIG_PREEMPT_NONE=y) reports a small reduction in text size:
add/remove: 0/0 grow/shrink: 18/578 up/down: 228/-5448 (-5220)
A larger improvement is achieved with the default configuration
but with CONFIG_PREEMPT=y and CONFIG_DEBUG_PREEMPT=n:
add/remove: 2/6 grow/shrink: 59/4477 up/down: 1618/-228762 (-227144)
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/thread_info.h')
| -rw-r--r-- | arch/s390/include/asm/thread_info.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h index f15c0398c363..933794150e5b 100644 --- a/arch/s390/include/asm/thread_info.h +++ b/arch/s390/include/asm/thread_info.h @@ -34,7 +34,6 @@ struct thread_info { unsigned long flags; /* low level flags */ unsigned long sys_call_table; /* System call table address */ unsigned int cpu; /* current CPU */ - int preempt_count; /* 0 => preemptable, <0 => BUG */ unsigned int system_call; __u64 user_timer; __u64 system_timer; @@ -49,7 +48,6 @@ struct thread_info { .task = &tsk, \ .flags = 0, \ .cpu = 0, \ - .preempt_count = INIT_PREEMPT_COUNT, \ } #define init_thread_info (init_thread_union.thread_info) |