[ovs-dev] [PATCH v2] ovs rcu: update rcu pointer first

[Linhaifeng]

Hi, Ben

Will this patch apply ?

> -----Original Message-----
> From: Ilya Maximets [mailto:i.maximets at ovn.org]
> Sent: Wednesday, June 3, 2020 10:33 PM
> To: Linhaifeng <haifeng.lin at huawei.com>; Ilya Maximets
> <i.maximets at ovn.org>; Ben Pfaff <blp at ovn.org>
> Cc: dev at openvswitch.org; Lilijun (Jerry) <jerry.lilijun at huawei.com>; Lichunhe
> <lichunhe at huawei.com>; nd <nd at arm.com>; chenchanghu
> <chenchanghu at huawei.com>
> Subject: Re: [ovs-dev] [PATCH v2] ovs rcu: update rcu pointer first
> 
> The change could look like this:
> 
> diff --git a/lib/ovs-rcu.c b/lib/ovs-rcu.c index ebc8120f0..cde1e925b 100644
> --- a/lib/ovs-rcu.c
> +++ b/lib/ovs-rcu.c
> @@ -30,6 +30,8 @@
> 
>  VLOG_DEFINE_THIS_MODULE(ovs_rcu);
> 
> +#define MIN_CBS 16
> +
>  struct ovsrcu_cb {
>      void (*function)(void *aux);
>      void *aux;
> @@ -37,7 +39,8 @@ struct ovsrcu_cb {
> 
>  struct ovsrcu_cbset {
>      struct ovs_list list_node;
> -    struct ovsrcu_cb cbs[16];
> +    struct ovsrcu_cb *cbs;
> +    size_t n_allocated;
>      int n_cbs;
>  };
> 
> @@ -310,16 +313,19 @@ ovsrcu_postpone__(void (*function)(void *aux), void
> *aux)
>      cbset = perthread->cbset;
>      if (!cbset) {
>          cbset = perthread->cbset = xmalloc(sizeof *perthread->cbset);
> +        cbset->cbs = xmalloc(MIN_CBS * sizeof *cbset->cbs);
> +        cbset->n_allocated = MIN_CBS;
>          cbset->n_cbs = 0;
>      }
> 
> +    if (cbset->n_cbs == cbset->n_allocated) {
> +        cbset->cbs = x2nrealloc(cbset->cbs, &cbset->n_allocated,
> +                                sizeof *cbset->cbs);
> +    }
> +
>      cb = &cbset->cbs[cbset->n_cbs++];
>      cb->function = function;
>      cb->aux = aux;
> -
> -    if (cbset->n_cbs >= ARRAY_SIZE(cbset->cbs)) {
> -        ovsrcu_flush_cbset(perthread);
> -    }
>  }
> 
>  static bool
> @@ -341,6 +347,7 @@ ovsrcu_call_postponed(void)
>          for (cb = cbset->cbs; cb < &cbset->cbs[cbset->n_cbs]; cb++) {
>              cb->function(cb->aux);
>          }
> +        free(cbset->cbs);
>          free(cbset);
>      }
> 
> ---
> 
> 
> I could submit a formal patch, if agreed.
> 
> Ben, what do you think?