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From: Bruce Richardson <bruce.richardson@intel.com>
To: Harry van Haaren <harry.van.haaren@intel.com>
Cc: <dev@dpdk.org>, <bruce-richardson@intel.com>
Subject: Re: [PATCH v2 1/2] event/sw: fix ordering corruption with op release
Date: Thu, 14 Sep 2023 12:12:53 +0100	[thread overview]
Message-ID: <ZQLqtUNaZtdocbuB@bricha3-MOBL.ger.corp.intel.com> (raw)
In-Reply-To: <20230914105852.82471-1-harry.van.haaren@intel.com>

On Thu, Sep 14, 2023 at 11:58:51AM +0100, Harry van Haaren wrote:
> This commit changes the logic in the scheduler to always
> reset reorder-buffer (and QID/FID) entries when writing
> them. This avoids stale ROB/QID/FID data re-use, which
> previously caused ordering issues.
> 
> Before this commit, release events left the history-list
> in an inconsistent state, and future events with op type of
> forward could be incorrectly reordered.
> 
> Suggested-by: Bruce Richardson <bruce.richardson@intel.com>
> Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
> 

Acked-by: Bruce Richardson <bruce.richardson@intel.com>

Couple of very minor style comments below.

> ---
> 
> v2:
> - Rework fix to simpler suggestion (Bruce)
> - Respin patchset to "apply order" (Bruce)
> 
> ---
>  drivers/event/sw/sw_evdev_scheduler.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/event/sw/sw_evdev_scheduler.c b/drivers/event/sw/sw_evdev_scheduler.c
> index de6ed21643..21c360770e 100644
> --- a/drivers/event/sw/sw_evdev_scheduler.c
> +++ b/drivers/event/sw/sw_evdev_scheduler.c
> @@ -90,8 +90,10 @@ sw_schedule_atomic_to_cq(struct sw_evdev *sw, struct sw_qid * const qid,
>  		sw->cq_ring_space[cq]--;
>  
>  		int head = (p->hist_head++ & (SW_PORT_HIST_LIST-1));
> -		p->hist_list[head].fid = flow_id;
> -		p->hist_list[head].qid = qid_id;
> +		p->hist_list[head] = (struct sw_hist_list_entry) {
> +			.qid = qid_id,
> +			.fid = flow_id,
> +		};
>  
>  		p->stats.tx_pkts++;
>  		qid->stats.tx_pkts++;
> @@ -162,8 +164,13 @@ sw_schedule_parallel_to_cq(struct sw_evdev *sw, struct sw_qid * const qid,
>  		qid->stats.tx_pkts++;
>  
>  		const int head = (p->hist_head & (SW_PORT_HIST_LIST-1));
> -		p->hist_list[head].fid = SW_HASH_FLOWID(qe->flow_id);
> -		p->hist_list[head].qid = qid_id;
> +		const uint32_t fid = SW_HASH_FLOWID(qe->flow_id);
> +		p->hist_list[head] = (struct sw_hist_list_entry) {
> +			.qid = qid_id,
> +			.fid = fid,
> +		};
> +
> +
You're adding some extra whitespace here. Can probably be fixed on apply.

And one final minor nit: if doing a new version, you can remove the
temporary variable for "fid". In my suggestion I only added it because I
had the assignment done on a single line and didn't want to wrap. Since
you've split the temporary struct across multiple lines, the temporary
variable isn't needed as the SW_HASH_FLOWID will fit on the assignment
line.

  parent reply	other threads:[~2023-09-14 11:13 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-31 16:47 [PATCH 1/2] event/sw: add selftest for ordered history list Harry van Haaren
2023-08-31 16:47 ` [PATCH 2/2] event/sw: fix ordering corruption with op release Harry van Haaren
2023-09-04 16:37   ` Bruce Richardson
2023-09-08 16:22     ` Van Haaren, Harry
2023-09-14 10:58   ` [PATCH v2 1/2] " Harry van Haaren
2023-09-14 10:58     ` [PATCH v2 2/2] event/sw: add selftest for ordered history list Harry van Haaren
2023-09-14 11:13       ` Bruce Richardson
2023-10-02 10:58       ` [PATCH v3 1/2] event/sw: fix ordering corruption with op release Harry van Haaren
2023-10-02 10:58         ` [PATCH v3 2/2] event/sw: add selftest for ordered history list Harry van Haaren
2023-10-03  6:38         ` [PATCH v3 1/2] event/sw: fix ordering corruption with op release Jerin Jacob
2023-09-14 11:12     ` Bruce Richardson [this message]
2023-08-31 17:10 ` [PATCH 1/2] event/sw: add selftest for ordered history list Bruce Richardson

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