patches for DPDK stable branches
 help / color / mirror / Atom feed
From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: Feifei Wang <feifei.wang2@arm.com>,
	"Yigit, Ferruh" <ferruh.yigit@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>, "nd@arm.com" <nd@arm.com>,
	"stable@dpdk.org" <stable@dpdk.org>,
	Ruifeng Wang <ruifeng.wang@arm.com>
Subject: Re: [dpdk-stable] [RFC PATCH v2 4/5] lib/bpf: use wait event scheme for Rx/Tx iteration
Date: Fri, 24 Sep 2021 18:07:45 +0000
Message-ID: <DM6PR11MB4491BDB787745D60AB489EF69AA49@DM6PR11MB4491.namprd11.prod.outlook.com> (raw)
In-Reply-To: <20210923095902.301762-5-feifei.wang2@arm.com>


> 
> First, fix the bug that keyword const of func arg should be after "*".

I believe there is no bug here.

> This is because const before "*" means the value of "cbi" should not be
> changed. 

Exactly, it says that the function itself will not change the value of "cbi".
It just waits for the value to be changed by someone else.
So please keep parameter list intact.

> But we should monitor that cbi->use changed and then we can
> jump out of loop.
> 
> Second, instead of polling for cbi->use to be updated, use
> wait event scheme.
> 
> Fixes: a93ff62a8938 ("bpf: introduce basic Rx/Tx filters")
> Cc: konstantin.ananyev@intel.com
> Cc: stable@dpdk.org
> 
> Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> ---
>  lib/bpf/bpf_pkt.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/bpf/bpf_pkt.c b/lib/bpf/bpf_pkt.c
> index 6e8248f0d6..08ed8ff68c 100644
> --- a/lib/bpf/bpf_pkt.c
> +++ b/lib/bpf/bpf_pkt.c
> @@ -111,9 +111,9 @@ bpf_eth_cbi_unuse(struct bpf_eth_cbi *cbi)
>   * Waits till datapath finished using given callback.
>   */
>  static void
> -bpf_eth_cbi_wait(const struct bpf_eth_cbi *cbi)
> +bpf_eth_cbi_wait(struct bpf_eth_cbi *const cbi)
>  {
> -	uint32_t nuse, puse;
> +	uint32_t puse;
> 
>  	/* make sure all previous loads and stores are completed */
>  	rte_smp_mb();
> @@ -122,11 +122,8 @@ bpf_eth_cbi_wait(const struct bpf_eth_cbi *cbi)
> 
>  	/* in use, busy wait till current RX/TX iteration is finished */
>  	if ((puse & BPF_ETH_CBI_INUSE) != 0) {
> -		do {
> -			rte_pause();
> -			rte_compiler_barrier();
> -			nuse = cbi->use;
> -		} while (nuse == puse);
> +		rte_compiler_barrier();
> +		rte_wait_event_32(&cbi->use, UINT_MAX, puse, ==, __ATOMIC_RELAXED);
>  	}
>  }
> 
> --
> 2.25.1


  reply	other threads:[~2021-09-24 18:07 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210902053253.3017858-1-feifei.wang2@arm.com>
2021-09-02  5:32 ` [dpdk-stable] [RFC PATCH v1 4/5] lib/bpf: use wait until " Feifei Wang
     [not found] ` <20210923095902.301762-1-feifei.wang2@arm.com>
2021-09-23  9:59   ` [dpdk-stable] [RFC PATCH v2 4/5] lib/bpf: use wait event " Feifei Wang
2021-09-24 18:07     ` Ananyev, Konstantin [this message]
2021-09-26  2:19       ` [dpdk-stable] 回复: " Feifei Wang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=DM6PR11MB4491BDB787745D60AB489EF69AA49@DM6PR11MB4491.namprd11.prod.outlook.com \
    --to=konstantin.ananyev@intel.com \
    --cc=dev@dpdk.org \
    --cc=feifei.wang2@arm.com \
    --cc=ferruh.yigit@intel.com \
    --cc=nd@arm.com \
    --cc=ruifeng.wang@arm.com \
    --cc=stable@dpdk.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

patches for DPDK stable branches

This inbox may be cloned and mirrored by anyone:

	git clone --mirror http://inbox.dpdk.org/stable/0 stable/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 stable stable/ http://inbox.dpdk.org/stable \
		stable@dpdk.org
	public-inbox-index stable

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.stable


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git