From: Yunsheng Lin <linyunsheng@huawei.com>
To: <davem@davemloft.net>, <kuba@kernel.org>, <edumazet@google.com>
Cc: <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linuxarm@openeuler.org>, <yoshfuji@linux-ipv6.org>,
<dsahern@kernel.org>
Subject: Re: [PATCH net-next] tcp: add tcp_tx_skb_cache_key checking in sk_stream_alloc_skb()
Date: Thu, 2 Sep 2021 08:47:51 +0800 [thread overview]
Message-ID: <ba7a0854-6841-2ebc-c329-4c13f1a997df@huawei.com> (raw)
In-Reply-To: <1630492744-60396-1-git-send-email-linyunsheng@huawei.com>
On 2021/9/1 18:39, Yunsheng Lin wrote:
> Since tcp_tx_skb_cache is disabled by default in:
> commit 0b7d7f6b2208 ("tcp: add tcp_tx_skb_cache sysctl")
>
> Add tcp_tx_skb_cache_key checking in sk_stream_alloc_skb() to
> avoid possible branch-misses.
>
> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
> ---
> Also, the sk->sk_tx_skb_cache may be both changed by allocation
> and freeing side, I assume there may be some implicit protection
> here too, such as the NAPI protection for rx?
Hi, Eric
Is there any implicit protection for sk->sk_tx_skb_cache?
As my understanding, sk_stream_alloc_skb() seems to be protected
by lock_sock(), and the sk_wmem_free_skb() seems to be mostly
happening in NAPI polling for TCP(when ack packet is received)
without lock_sock(), so it seems there is no protection here?
>
next prev parent reply other threads:[~2021-09-02 0:47 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-01 10:39 Yunsheng Lin
2021-09-01 10:52 ` Paolo Abeni
2021-09-01 15:06 ` Eric Dumazet
2021-09-01 15:16 ` Eric Dumazet
2021-09-01 15:25 ` Paolo Abeni
2021-09-01 15:29 ` Eric Dumazet
2021-09-01 16:01 ` Paolo Abeni
2021-09-01 16:02 ` Eric Dumazet
2021-09-02 0:47 ` Yunsheng Lin [this message]
2021-09-02 1:13 ` Eric Dumazet
2021-09-02 2:05 ` Yunsheng Lin
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