Date: Fri, 7 Jul 2017 08:22:22 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Shivappa Vikas <vikas.shivappa@intel.com>
cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, hpa@zytor.com, peterz@infradead.org,
        ravi.v.shankar@intel.com, tony.luck@intel.com, fenghua.yu@intel.com,
        andi.kleen@intel.com
Subject: Re: [PATCH 14/21] x86/intel_rdt/cqm: Add mon_data
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References: <1498503368-20173-1-git-send-email-vikas.shivappa@linux.intel.com> <1498503368-20173-15-git-send-email-vikas.shivappa@linux.intel.com> <alpine.DEB.2.20.1707021432030.2296@nanos> <alpine.DEB.2.10.1707061447150.3798@vshiva-Udesk>
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On Thu, 6 Jul 2017, Shivappa Vikas wrote:
> On Sun, 2 Jul 2017, Thomas Gleixner wrote:
> > > +static bool __mon_event_count(u32 rmid, struct rmid_read *rr)
> > > +{
> > > +	u64 tval;
> > > +
> > > +	tval = __rmid_read(rmid, rr->evtid);
> > > +	if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) {
> > > +		rr->val = tval;
> > > +		return false;
> > > +	}
> > > +	switch (rr->evtid) {
> > > +	case QOS_L3_OCCUP_EVENT_ID:
> > > +		rr->val += tval;
> > > +		return true;
> > > +	default:
> > > +		return false;
> > 
> > I have no idea what that return code means.
> 
> false for the invalid event id and all errors for __rmid_read. (IOW all errors
> for __mon_event-read)

Sure, but why bool? What's wrong with proper error return codes, so issues
can be distinguished and potentially propagated in the callchain?

Thanks,

	tglx