Re: [ovs-dev] [PATCH net-next v8 1/1] net: openvswitch: reduce cpu_used_mask memory

[Eddy Tao]

Yes, Eelco, this is the last revision and no further comments for 
revision came in

eddy

On 2023/2/6 19:21, Eelco Chaudron wrote:
> On 5 Feb 2023, at 2:35, Eddy Tao wrote:
>
> > Use actual CPU number instead of hardcoded value to decide the size
> > of 'cpu_used_mask' in 'struct sw_flow'. Below is the reason.
> >
> > 'struct cpumask cpu_used_mask' is embedded in struct sw_flow.
> > Its size is hardcoded to CONFIG_NR_CPUS bits, which can be
> > 8192 by default, it costs memory and slows down ovs_flow_alloc.
> >
> > To address this:
> >   Redefine cpu_used_mask to pointer.
> >   Append cpumask_size() bytes after 'stat' to hold cpumask.
> >   Initialization cpu_used_mask right after stats_last_writer.
> >
> > APIs like cpumask_next and cpumask_set_cpu never access bits
> > beyond cpu count, cpumask_size() bytes of memory is enough.
> >
> > Signed-off-by: Eddy Tao <taoyuan_eddy@xxxxxxxxxxx>
> The changes look good to me. Hopefully this is the last revision ;)
>
> Acked-by: Eelco Chaudron <echaudro@xxxxxxxxxx>