Re: [PATCH v9 3/7] srcu: Fix invoke_rcu_callbacks() segcb length adjustment

From: Joel Fernandes
Date: Tue Nov 03 2020 - 09:58:28 EST


On Tue, Nov 03, 2020 at 03:47:14PM +0100, Frederic Weisbecker wrote:
> On Tue, Nov 03, 2020 at 09:25:59AM -0500, Joel Fernandes (Google) wrote:
> > With earlier patches, the negative counting of the unsegmented list
> > cannot be used to adjust the segmented one. To fix this, sample the
> > unsegmented length in advance, and use it after CB execution to adjust
> > the segmented list's length.
> >
> > Reviewed-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
> > Suggested-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
> > Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
>
> This breaks bisection, you need to either fix up the previous patch
> by adding this diff inside or better yet: expand what you did
> in "rcu/tree: Make rcu_do_batch count how many callbacks were executed"
> to also handle srcu before introducing the segcb count.

Right, the latter is better. Let us do that.

thanks,

- Joel