linux-kernel - Re: [PATCH RESEND net-next] bnxt_en: use dev_consume_skb_any() in bnxt_tx

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Message-ID: <CADxym3YHmKOQ+pL+s6vuyTwE1FZ8D4uaYVcF13OjGrzgrFK=Pw@mail.gmail.com>
Date:   Tue, 11 Jul 2023 16:53:59 +0800
From:   Menglong Dong <menglong8.dong@...il.com>
To:     Leon Romanovsky <leon@...nel.org>
Cc:     michael.chan@...adcom.com, davem@...emloft.net,
        edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Menglong Dong <imagedong@...cent.com>
Subject: Re: [PATCH RESEND net-next] bnxt_en: use dev_consume_skb_any() in bnxt_tx_int

On Tue, Jul 11, 2023 at 2:31 PM Leon Romanovsky <leon@...nel.org> wrote:
>
> On Mon, Jul 10, 2023 at 05:47:47PM +0800, menglong8.dong@...il.com wrote:
> > From: Menglong Dong <imagedong@...cent.com>
> >
> > Replace dev_kfree_skb_any() with dev_consume_skb_any() in bnxt_tx_int()
> > to clear the unnecessary noise of "kfree_skb" event.
>
> Can you please be more specific in the commit message what "unnecessary
> noise" you reduced?

OK! How about the description like this:

In bnxt_tx_int(), the skb in the tx ring buffer will be freed after the
transmission completes with dev_kfree_skb_any(), which will produce
noise on the tracepoint "skb:kfree_skb":

$ perf record -e skb:kfree_skb -a
$ perf script
         swapper     0 [006]  5072.553459: skb:kfree_skb:
skbaddr=0xffff88810ec47700 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [006]  5072.554796: skb:kfree_skb:
skbaddr=0xffff8881370348e0 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [006]  5072.554806: skb:kfree_skb:
skbaddr=0xffff888137035ae0 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [010]  5072.605012: skb:kfree_skb:
skbaddr=0xffff8881372926e0 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [010]  5072.648249: skb:kfree_skb:
skbaddr=0xffff8881372916e0 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [010]  5072.655732: skb:kfree_skb:
skbaddr=0xffff8881372928e0 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [010]  5072.697115: skb:kfree_skb:
skbaddr=0xffff8881372916e0 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [010]  5072.744718: skb:kfree_skb:
skbaddr=0xffff8881372928e0 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [010]  5072.786947: skb:kfree_skb:
skbaddr=0xffff8881372916e0 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [010]  5072.838535: skb:kfree_skb:
skbaddr=0xffff8881372928e0 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED
         swapper     0 [003]  5072.853599: skb:kfree_skb:
skbaddr=0xffff888108380500 protocol=2048
location=dev_kfree_skb_any_reason+0x2e reason: NOT_SPECIFIED

Replace dev_kfree_skb_any() with dev_consume_skb_any() in bnxt_tx_int()
to reduce the noise.


Thanks!
Menglong Dong


>
> >
> > Signed-off-by: Menglong Dong <imagedong@...cent.com>
> > ---
> >  drivers/net/ethernet/broadcom/bnxt/bnxt.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
>
> Thanks,
> Reviewed-by: Leon Romanovsky <leonro@...dia.com>