Re: [patch 4/4] fs: jbd/jbd2: Substitute BH locks for RT and lock debugging

From: Jan Kara
Date: Thu Aug 01 2019 - 04:44:16 EST

On Wed 31-07-19 21:40:42, Thomas Gleixner wrote:
> On Wed, 31 Jul 2019, Jan Kara wrote:
> > BH_State lock is definitely worth it. In fact, if you placed the spinlock
> > inside struct journal_head (which is the structure whose members are in
> > fact protected by it), I'd be even fine with just using the spinlock always
> > instead of the bit spinlock. journal_head is pretty big anyway (and there's
> > even 4-byte hole in it for 64-bit archs) and these structures are pretty
> > rare (only for actively changed metadata buffers).
> Just need to figure out what to do with the ASSERT_JH(state_is_locked) case for
> UP. Perhaps just return true for UP && !DEBUG_SPINLOCK?

Yes, that makes sense.

Jan Kara <jack@xxxxxxxx>