Re: [PATCH] fs/netfs: Remove redundant use of smp_rmb()

[David Howells <dhowells@redhat.com>]

Akira Yokosawa <akiyks@gmail.com> wrote:

> Are you sure removing the smp_rmb() is realy the right thing to do?

The wait_on_bit*() class functions, e.g.:

	wait_on_bit(unsigned long *word, int bit, unsigned mode)
	{
		might_sleep();
		if (!test_bit_acquire(bit, word))
			return 0;
		return out_of_line_wait_on_bit(word, bit,
					       bit_wait,
					       mode);
	}

now unconditionally includes an appropriate barrier on the test_bit(), so the
smp_rmb() should be unnecessary, though netfslib should probably be using
clear_and_wake_up_bit().

Probably we need to update the doc to reflect this.

David