Subject: Re: [REGRESSION, v3.7-rc5, bisected] 100% CPU usage in softirqd, unable to shutdown(Internet mail)

From: Lekensteyn <[email-masked]>
Date: Tue, 13 Nov 2012 19:25:50 +0100

On Tuesday 13 November 2012 10:26:03 dannyfeng wrote:
> I'm sorry, I didn't noticed that jme_open use tasklet_enable, which may
> reuse a killed tasklet... Could you please try following patch?
> ---
> diff --git a/drivers/net/ethernet/jme.c b/drivers/net/ethernet/jme.c
> index 92317e9..c0314c1 100644
> --- a/drivers/net/ethernet/jme.c
> +++ b/drivers/net/ethernet/jme.c
> @@ -1860,10 +1860,14 @@ jme_open(struct net_device *netdev)
>         jme_clear_pm(jme);
>         JME_NAPI_ENABLE(jme);
>  
> -       tasklet_enable(&jme->linkch_task);
> -       tasklet_enable(&jme->txclean_task);
> -       tasklet_hi_enable(&jme->rxclean_task);
> -       tasklet_hi_enable(&jme->rxempty_task);
> +       tasklet_init(&jme->linkch_task, jme_link_change_tasklet,
> +                     (unsigned long) jme);
> +       tasklet_init(&jme->txclean_task, jme_tx_clean_tasklet,
> +                     (unsigned long) jme);
> +       tasklet_init(&jme->rxclean_task, jme_rx_clean_tasklet,
> +                     (unsigned long) jme);
> +       tasklet_init(&jme->rxempty_task, jme_rx_empty_tasklet,
> +                     (unsigned long) jme);
>  
>         rc = jme_request_irq(jme);
>         if (rc)
> @@ -3079,22 +3083,6 @@ jme_init_one(struct pci_dev *pdev,
>         tasklet_init(&jme->pcc_task,
>                      jme_pcc_tasklet,
>                      (unsigned long) jme);
> -       tasklet_init(&jme->linkch_task,
> -                    jme_link_change_tasklet,
> -                    (unsigned long) jme);
> -       tasklet_init(&jme->txclean_task,
> -                    jme_tx_clean_tasklet,
> -                    (unsigned long) jme);
> -       tasklet_init(&jme->rxclean_task,
> -                    jme_rx_clean_tasklet,
> -                    (unsigned long) jme);
> -       tasklet_init(&jme->rxempty_task,
> -                    jme_rx_empty_tasklet,
> -                    (unsigned long) jme);
> -       tasklet_disable_nosync(&jme->linkch_task);
> -       tasklet_disable_nosync(&jme->txclean_task);
> -       tasklet_disable_nosync(&jme->rxclean_task);
> -       tasklet_disable_nosync(&jme->rxempty_task);
>         jme->dpi.cur = PCC_P1;
>  
>         jme->reg_ghc = 0;
Tested-by: Peter Wu <[email-masked]>

I have no idea what this does, but it seems to help as I can suspend/resume 
without rapidly rising softirqs. (applied on top of 3.7-rc5.)

I tested it like this:
- rmmod jme
- insmod <path to new patched build>/jme.ko

I hand-edited the code as your patch does not apply due to tab to space 
conversion. You might want to use a real email client instead of the web 
interface.

Regards,
Peter