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From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Matan Azrad <matan@mellanox.com>
Cc: dev@dpdk.org, Viacheslav Ovsiienko <viacheslavo@mellanox.com>
Subject: Re: [dpdk-dev] [PATCH v2 1/3] vdpa/mlx5: optimize notification events
Date: Mon, 29 Jun 2020 11:05:22 +0200
Message-ID: <abfd6c1e-d61d-5229-8216-12fc06600560@redhat.com> (raw)
In-Reply-To: <1593091838-51869-2-git-send-email-matan@mellanox.com>



On 6/25/20 3:30 PM, Matan Azrad wrote:
> When the virtio guest driver doesn't work with poll mode, the driver
> creates event mechanism in order to schedule completion notifications
> for each virtq burst traffic.
> 
> When traffic comes to a virtq, a CQE will be added to the virtq CQ by
> the FW.
> The driver requests interrupt for the next CQE index, and when interrupt
> is triggered, the driver polls the CQ and notifies the guest by virtq
> callfd writing.
> 
> According to the described method, the interrupts will be triggered for
> each burst of trrafic. The burst size depends on interrupt latancy.
> 
> Interrupts management takes a lot of CPU cycles and using it for each
> traffic burst takes big portion of CPU capacity.
> 
> When traffic is on, using timer for CQ poll scheduling instead of
> interrupts saves a lot of CPU cycles.
> 
> Move CQ poll scheduling to be done by timer in case of running traffic.
> Request interrupts only when traffic is off.
> 
> The timer scheduling management is done by a new dedicated thread uses
> a usleep command.
> 
> Signed-off-by: Matan Azrad <matan@mellanox.com>
> ---
>  drivers/vdpa/mlx5/Makefile          |   1 +
>  drivers/vdpa/mlx5/mlx5_vdpa.h       |   7 ++
>  drivers/vdpa/mlx5/mlx5_vdpa_event.c | 175 ++++++++++++++++++++++++++++++------
>  3 files changed, 157 insertions(+), 26 deletions(-)
> 

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime


  reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-18 19:11 [dpdk-dev] [PATCH 0/3] vdpa/mlx5: optimize cpu utilization Matan Azrad
2020-06-18 19:11 ` [dpdk-dev] [PATCH 1/3] vdpa/mlx5: optimize notification events Matan Azrad
2020-06-18 19:11 ` [dpdk-dev] [PATCH 2/3] vdpa/mlx5: optimize completion queue poll Matan Azrad
2020-06-18 19:11 ` [dpdk-dev] [PATCH 3/3] vdpa/mlx5: add traffic control device arguments Matan Azrad
2020-06-25 13:30 ` [dpdk-dev] [PATCH v2 0/3] vdpa/mlx5: optimize cpu utilization Matan Azrad
2020-06-25 13:30   ` [dpdk-dev] [PATCH v2 1/3] vdpa/mlx5: optimize notification events Matan Azrad
2020-06-29  9:05     ` Maxime Coquelin [this message]
2020-06-25 13:30   ` [dpdk-dev] [PATCH v2 2/3] vdpa/mlx5: optimize completion queue poll Matan Azrad
2020-06-29  9:11     ` Maxime Coquelin
2020-06-25 13:30   ` [dpdk-dev] [PATCH v2 3/3] vdpa/mlx5: control completion queue event mode Matan Azrad
2020-06-29  9:16     ` Maxime Coquelin
2020-06-29 14:01   ` [dpdk-dev] [PATCH v3 0/3] vdpa/mlx5: optimize cpu utilization Matan Azrad
2020-06-29 14:01     ` [dpdk-dev] [PATCH v3 1/3] vdpa/mlx5: optimize notification events Matan Azrad
2020-06-29 14:01     ` [dpdk-dev] [PATCH v3 2/3] vdpa/mlx5: optimize completion queue poll Matan Azrad
2020-06-29 14:01     ` [dpdk-dev] [PATCH v3 3/3] vdpa/mlx5: control completion queue event mode Matan Azrad
2020-06-29 17:24     ` [dpdk-dev] [PATCH v3 0/3] vdpa/mlx5: optimize cpu utilization Maxime Coquelin

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