On Wed, Feb 26, 2025 at 02:21 PM -08, Cong Wang wrote:
> On Wed, Feb 26, 2025 at 02:49:17PM +0100, Jakub Sitnicki wrote:
>> On Sat, Feb 22, 2025 at 10:30 AM -08, Cong Wang wrote:
>> > From: Cong Wang <cong.wang@xxxxxxxxxxxxx>
>> >
>> > psock->eval can only have 4 possible values, make it 8-bit is
>> > sufficient.
>> >
>> > psock->redir_ingress is just a boolean, using 1 bit is enough.
>> >
>> > Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
>> > ---
>> > include/linux/skmsg.h | 4 ++--
>> > 1 file changed, 2 insertions(+), 2 deletions(-)
>> >
>> > diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
>> > index bf28ce9b5fdb..beaf79b2b68b 100644
>> > --- a/include/linux/skmsg.h
>> > +++ b/include/linux/skmsg.h
>> > @@ -85,8 +85,8 @@ struct sk_psock {
>> > struct sock *sk_redir;
>> > u32 apply_bytes;
>> > u32 cork_bytes;
>> > - u32 eval;
>> > - bool redir_ingress; /* undefined if sk_redir is null */
>> > + unsigned int eval : 8;
>> > + unsigned int redir_ingress : 1; /* undefined if sk_redir is null */
>> > struct sk_msg *cork;
>> > struct sk_psock_progs progs;
>> > #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
>>
>> Are you doing this bit packing to create a hole big enough to fit
>> another u32 introduced in the next patch?
>
> Kinda, or at least trying to save some space for the next patch. I am
> not yet trying to reorder them to make it more packed, because it can
> be a separate patch.
OK. Asking because the intention is not expressed in the description.
Nit: Why the switch to an implicitly sized integer type?
It feels a bit silly when you can just declare an `u8 eval`.
