linux-kernel - Re: [PATCH 1/1] video: hyperv_fb: Add ratelimit on error message

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Message-ID: <20210420194850.ykxb3yy75zvzqfun@liuwe-devbox-debian-v2>
Date:   Tue, 20 Apr 2021 19:48:50 +0000
From:   Wei Liu <wei.liu@...nel.org>
To:     Michael Kelley <mikelley@...rosoft.com>
Cc:     kys@...rosoft.com, haiyangz@...rosoft.com, sthemmin@...rosoft.com,
        wei.liu@...nel.org, linux-kernel@...r.kernel.org,
        linux-hyperv@...r.kernel.org, linux-fbdev@...r.kernel.org,
        dri-devel@...ts.freedesktop.org
Subject: Re: [PATCH 1/1] video: hyperv_fb: Add ratelimit on error message

On Tue, Apr 20, 2021 at 08:44:19AM -0700, Michael Kelley wrote:
> Due to a full ring buffer, the driver may be unable to send updates to
> the Hyper-V host.  But outputing the error message can make the problem
> worse because console output is also typically written to the frame
> buffer.  As a result, in some circumstances the error message is output
> continuously.
> 
> Break the cycle by rate limiting the error message.  Also output
> the error code for additional diagnosability.
> 
> Signed-off-by: Michael Kelley <mikelley@...rosoft.com>

Applied to hyperv-next. Thanks.

> ---
>  drivers/video/fbdev/hyperv_fb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
> index 4dc9077..a7e6eea 100644
> --- a/drivers/video/fbdev/hyperv_fb.c
> +++ b/drivers/video/fbdev/hyperv_fb.c
> @@ -308,7 +308,7 @@ static inline int synthvid_send(struct hv_device *hdev,
>  			       VM_PKT_DATA_INBAND, 0);
>  
>  	if (ret)
> -		pr_err("Unable to send packet via vmbus\n");
> +		pr_err_ratelimited("Unable to send packet via vmbus; error %d\n", ret);
>  
>  	return ret;
>  }
> -- 
> 1.8.3.1
>