• Andy Lutomirski's avatar
    sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK · 68f24b08
    Andy Lutomirski authored
    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: default avatarAndy 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.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    68f24b08
fork.c 54.2 KB