RE: [PATCH 3/4] SunRPC: Use no_printk() for the null dprintk() anddfprintk()

From: Myklebust, Trond
Date: Thu Sep 26 2013 - 11:42:53 EST


> -----Original Message-----
> From: David Howells [mailto:dhowells@xxxxxxxxxx]
> Sent: Thursday, September 26, 2013 10:36 AM
> To: Joe Perches
> Cc: dhowells@xxxxxxxxxx; bfields@xxxxxxxxxxxx; Myklebust, Trond;
> olof@xxxxxxxxx; linux-nfs@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 3/4] SunRPC: Use no_printk() for the null dprintk() and
> dfprintk()
>
> Joe Perches <joe@xxxxxxxxxxx> wrote:
>
> > no_printk doesn't prevent any argument side-effects from being
> > optimized away by the compiler.
> >
> > ie:
> > dprintk("%d", func())
> > func is now always called when before it wasn't.
>
> Yes, I know. There are half a dozen places where this is the case. Those I've
> wrapped in ifdebug(FACILITY) { ... } in the code. It's not the nicest, but at
> least the compiler always gets to see everything, rather than bits of it getting
> hidden by the preprocessor - which means the call points will be less likely to
> bit rot over time.

Your assumption is that RPC_DEBUG is disabled for most compiles. That is not the case.

Trond
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/