Re: [PATCH 0/2] nfsd: improvements for wake_up_bit/var

[Santosh Pradhan <santosh.pradhan@xxxxxxxxx>]

Hi Neil,
Do we need a barrier in nfs4_disable_swap() as well ?

10830         set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
10831         clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state);
>>> HERE>>>>
10832         wake_up_var(&clp->cl_state);

Regards,
Santosh

On Fri, Aug 30, 2024 at 12:37 PM NeilBrown <neilb@xxxxxxx> wrote:
>
> I've been digging into wake_up_bit and wake_up_var recently.  There are
> a lot of places where the required barriers aren't quite right.
>
> This patch fixes them up for nfsd.  The bugs are mostly minor, though
> the rp_locked on might be a credible problem on weakly ordered hosts
> (e.g.  power64).
>
> NeilBrown
>
>  [PATCH 1/2] nfsd: use clear_and_wake_up_bit()
>  [PATCH 2/2] nfsd: avoid races with wake_up_var()
>