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References: <20230201170441.29756-1-giovanni.cabiddu@intel.com>
In-Reply-To: <20230201170441.29756-1-giovanni.cabiddu@intel.com>
From:   Vladis Dronov <vdronov@redhat.com>
Date:   Thu, 2 Feb 2023 17:55:07 +0100
Message-ID: <CAMusb+S_Fxyt-KMjK+-SFenuypdmziK6qJcriHaXP4iux=W5gQ@mail.gmail.com>
Subject: Re: [PATCH] crypto: qat - drop log level of msg in get_instance_node()
To:     Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Cc:     herbert@gondor.apana.org.au, linux-crypto@vger.kernel.org,
        qat-linux@intel.com, Fiona Trahe <fiona.trahe@intel.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi, Giovanni, all,

On Wed, Feb 1, 2023 at 6:05 PM Giovanni Cabiddu
<giovanni.cabiddu@intel.com> wrote:
>
> The functions qat_crypto_get_instance_node() and
> qat_compression_get_instance_node() allow to get a QAT instance (ring
> pair) on a device close to the node specified as input parameter.
> When this is not possible, and a QAT device is available in the system,
> these function return an instance on a remote node and they print a
> message reporting that it is not possible to find a device on the specified
> node. This is interpreted by people as an error rather than an info.
>
> The print "Could not find a device on node" indicates that a kernel
> application is running on a core in a socket that does not have a QAT
> device directly attached to it and performance might suffer.
>
> Due to the nature of the message, this can be considered as a debug
> message, therefore drop the severity to debug and report it only once
> to avoid flooding.
>
> Suggested-by: Vladis Dronov <vdronov@redhat.com>
> Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
> Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
> ---
>  drivers/crypto/qat/qat_common/qat_compression.c | 2 +-
>  drivers/crypto/qat/qat_common/qat_crypto.c      | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/crypto/qat/qat_common/qat_compression.c b/drivers/crypto/qat/qat_common/qat_compression.c
> index 9fd10f4242f8..3f1f35283266 100644
> --- a/drivers/crypto/qat/qat_common/qat_compression.c
> +++ b/drivers/crypto/qat/qat_common/qat_compression.c
> @@ -72,7 +72,7 @@ struct qat_compression_instance *qat_compression_get_instance_node(int node)
>         }
>
>         if (!accel_dev) {
> -               pr_info("QAT: Could not find a device on node %d\n", node);
> +               pr_debug_ratelimited("QAT: Could not find a device on node %d\n", node);
>                 /* Get any started device */
>                 list_for_each(itr, adf_devmgr_get_head()) {
>                         struct adf_accel_dev *tmp_dev;
> diff --git a/drivers/crypto/qat/qat_common/qat_crypto.c b/drivers/crypto/qat/qat_common/qat_crypto.c
> index e31199eade5b..40c8e74d1cf9 100644
> --- a/drivers/crypto/qat/qat_common/qat_crypto.c
> +++ b/drivers/crypto/qat/qat_common/qat_crypto.c
> @@ -70,7 +70,7 @@ struct qat_crypto_instance *qat_crypto_get_instance_node(int node)
>         }
>
>         if (!accel_dev) {
> -               pr_info("QAT: Could not find a device on node %d\n", node);
> +               pr_debug_ratelimited("QAT: Could not find a device on node %d\n", node);
>                 /* Get any started device */
>                 list_for_each_entry(tmp_dev, adf_devmgr_get_head(), list) {
>                         if (adf_dev_started(tmp_dev) &&
> --
> 2.39.1
>

Thanks, the fix seems to be working. It was tested on "Intel(R) Xeon(R)
Platinum 8468H / Sapphire Rapids 4 skt (SPR) XCC-SP, Qual E-3
stepping" machine with 8086:4940 (rev 40) QAT device:

Without the fix:

# dmesg | grep "QAT: Could not find a device" | wc -l
498

With the fix:

# dmesg | grep "QAT: Could not find a device"
<not output>

So,

Reviewed-by: Vladis Dronov <vdronov@redhat.com>
Tested-by: Vladis Dronov <vdronov@redhat.com>

Best regards,
Vladis Dronov | Red Hat, Inc. | The Core Kernel | Senior Software Engineer