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| author | Andy Lutomirski <luto@kernel.org> | 2016-09-15 22:45:48 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-09-16 09:18:54 +0200 |
| commit | 68f24b08ee892d47bdef925d676e1ae1ccc316f8 (patch) | |
| tree | eb68202da134522dd22c4bf78487ae9017df970f /include/linux/init_task.h | |
| parent | aa1f1a639621672b68f654dc815a7d8298ff396f (diff) | |
| download | linux-68f24b08ee892d47bdef925d676e1ae1ccc316f8.tar.gz | |
sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK
We currently keep every task's stack around until the task_struct
itself is freed. This means that we keep the stack allocation alive
for longer than necessary and that, under load, we free stacks in
big batches whenever RCU drops the last task reference. Neither of
these is good for reuse of cache-hot memory, and freeing in batches
prevents us from usefully caching small numbers of vmalloced stacks.
On architectures that have thread_info on the stack, we can't easily
change this, but on architectures that set THREAD_INFO_IN_TASK, we
can free it as soon as the task is dead.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/08ca06cde00ebed0046c5d26cbbf3fbb7ef5b812.1474003868.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/init_task.h')
| -rw-r--r-- | include/linux/init_task.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 9c04d44eeb3c1..325f649d77ff2 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -186,7 +186,9 @@ extern struct task_group root_task_group; #endif #ifdef CONFIG_THREAD_INFO_IN_TASK -# define INIT_TASK_TI(tsk) .thread_info = INIT_THREAD_INFO(tsk), +# define INIT_TASK_TI(tsk) \ + .thread_info = INIT_THREAD_INFO(tsk), \ + .stack_refcount = ATOMIC_INIT(1), #else # define INIT_TASK_TI(tsk) #endif |