netdev - Re: [PATCH net-next] virtio-net: Reduce debug name field size to 16 bytes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CALs4sv1qJRDBvjJh3mER6n4xgrgWJ1TRyWPYefO6aV4Hz0MwfA@mail.gmail.com>
Date:   Mon, 23 Jan 2023 19:42:35 +0530
From:   Pavan Chebbi <pavan.chebbi@...adcom.com>
To:     Parav Pandit <parav@...dia.com>
Cc:     mst@...hat.com, jasowang@...hat.com, netdev@...r.kernel.org,
        davem@...emloft.net, kuba@...nel.org, edumazet@...gle.com,
        pabeni@...hat.com, virtualization@...ts.linux-foundation.org
Subject: Re: [PATCH net-next] virtio-net: Reduce debug name field size to 16 bytes

On Mon, Jan 23, 2023 at 9:25 AM Parav Pandit <parav@...dia.com> wrote:
>
> virtio queue index can be maximum of 65535. 16 bytes are enough to store
> the vq name with the existing string prefix.
>
> With this change, send queue struct saves 24 bytes and receive
> queue saves whole cache line worth 64 bytes per structure
> due to saving in alignment bytes.
>
> Pahole results before:
>
> pahole -s drivers/net/virtio_net.o | \
>     grep -e "send_queue" -e "receive_queue"
> send_queue      1112    0
> receive_queue   1280    1
>
> Pahole results after:
> pahole -s drivers/net/virtio_net.o | \
>     grep -e "send_queue" -e "receive_queue"
> send_queue      1088    0
> receive_queue   1216    1
>
> Signed-off-by: Parav Pandit <parav@...dia.com>
> ---
>  drivers/net/virtio_net.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index a170b0075dcf..3855b8524300 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -134,7 +134,7 @@ struct send_queue {
>         struct scatterlist sg[MAX_SKB_FRAGS + 2];
>
>         /* Name of the send queue: output.$index */
> -       char name[40];
> +       char name[16];
>
>         struct virtnet_sq_stats stats;
>
> @@ -171,7 +171,7 @@ struct receive_queue {
>         unsigned int min_buf_len;
>
>         /* Name of this receive queue: input.$index */
> -       char name[40];
> +       char name[16];
>
>         struct xdp_rxq_info xdp_rxq;
>  };
> --
> 2.26.2
>

Looks good to me.
Reviewed-by: Pavan Chebbi <pavan.chebbi@...adcom.com>

Download attachment "smime.p7s" of type "application/pkcs7-signature" (4209 bytes)