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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 /kernel/sched | |
| parent | aa1f1a639621672b68f654dc815a7d8298ff396f (diff) | |
| download | linux-stable-68f24b08ee892d47bdef925d676e1ae1ccc316f8.tar.gz linux-stable-68f24b08ee892d47bdef925d676e1ae1ccc316f8.tar.bz2 linux-stable-68f24b08ee892d47bdef925d676e1ae1ccc316f8.zip | |
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 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0b6238f18da2..23c6037e2d89 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2772,6 +2772,10 @@ static struct rq *finish_task_switch(struct task_struct *prev) * task and put them back on the free list. */ kprobe_flush_task(prev); + + /* Task is done with its stack. */ + put_task_stack(prev); + put_task_struct(prev); } |