Re: [PATCH 1/4] Net device error logging, revised

[Jeff Garzik]

Jim Keniston wrote:
> Jeff Garzik wrote:
> > "NETIF_MSG_" is silly and should be eliminated.
>
>
> > From this, I infer that you think that the option to "omit" the msglevel arg --
> e.g.,
> 	netdev_err(dev,, "NIC is fried!\n");	/* always logged */
> -- is silly.  No big deal.  Its sole purpose is to help keep netdev_* calls terse.

yes


> > A separate "NETIF_MSG_ALL" test is not needed, because msg_enable is a
> > bitmask.  A msg_enable of 0xffffffff will naturally create a NETIF_MSG_ALL.
>
>
> But how do you code a netdev_* call where you ALWAYS want the message (including
> netdev_printk-style prefix) logged, regardless of the value of msg_enable?  That's
> what NETIF_MSG_ALL is for (and why it might be better called NETIF_MSG_ALWAYS)...

I understand the purpose of NETIF_MSG_ALL; re-read what I said.  You 
don't need a separate _test_, as your implementation includes.  Defining 
NETIF_MSG_ALL to 0xffffffff will naturally create the effect you seek.


> > Also, whatever mechanism is created, it needs to preserve the feature of
> > the existing system:
> >
> >        if (a quick bitmask test)
> >                do something
> >
> > And preferably "do something" is not inlined, because printk'ing --
> > although it may appear in a fast path during debugging -- cannot be
> > considered a fast path itself.

> Sorry, I'm not sure what you're getting at here.  netdev_* doesn't prevent
> people from using the existing netif_msg_* macros; it just provides shorthand
> for the (usual) case where "do something" is "printk".


I would prefer to be more ambitious.  If we're gonna go in and change 
every printk in a driver, we might as well do it right, and (a) make 
sure the driver does msg_enable, and (b) make the source code a bit more 
clean by hiding the "if (test bitmap)" test in your netdev_xxx stuff.

	Jeff


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