Re: thread group comments

From: Andi Kleen (ak@suse.de)
Date: Fri Sep 01 2000 - 21:21:24 EDT

  • Next message: David S. Miller: "Re: Linux 2.2.18pre2"

    On Fri, Sep 01, 2000 at 06:15:52PM -0700, Linus Torvalds wrote:
    >
    > if (!has_done_this_before) {
    > pid_t tid;
    > has_done_this_before = 1;
    > tid = clone(CLONE_PID);

    I'm not sure this will work very well (2.4.0test8-pre1):

    int do_fork(unsigned long clone_flags, unsigned long usp, struct pt_regs *regs)
    {
            int retval = -ENOMEM;
            struct task_struct *p;
            DECLARE_MUTEX_LOCKED(sem);

            if (clone_flags & CLONE_PID) {
                    /* This is only allowed from the boot up thread */
                    if (current->pid)
                            return -EPERM;
            }

    So it would require fixing CLONE_PID first, which is probably nasty.

    Without it it'll still require the context switches when you're calling
    pthread_create from the "original" thread.

    -Andi
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    Please read the FAQ at http://www.tux.org/lkml/

    This archive was generated by hypermail 2b29 : Fri Sep 01 2000 - 21:23:36 EDT