Message-ID: <1432308615.1428.10.camel@misato.fc.hp.com>
Subject: Re: [PATCH v9 8/10] x86, mm: Add set_memory_wt() for WT
From: Toshi Kani <toshi.kani@hp.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: hpa@zytor.com, mingo@redhat.com, akpm@linux-foundation.org, arnd@arndb.de,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org, x86@kernel.org,
        linux-nvdimm@ml01.01.org, jgross@suse.com, stefan.bader@canonical.com,
        luto@amacapital.net, hmh@hmh.eng.br, yigal@plexistor.com,
        konrad.wilk@oracle.com, Elliott@hp.com, mcgrof@suse.com, hch@lst.de
Date: Fri, 22 May 2015 09:30:15 -0600
In-Reply-To: <alpine.DEB.2.11.1505220944340.5457@nanos>
References: <1431551151-19124-1-git-send-email-toshi.kani@hp.com>
	 <1431551151-19124-9-git-send-email-toshi.kani@hp.com>
	 <alpine.DEB.2.11.1505220944340.5457@nanos>
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On Fri, 2015-05-22 at 09:48 +0200, Thomas Gleixner wrote:
> On Wed, 13 May 2015, Toshi Kani wrote:
> > +int set_memory_wt(unsigned long addr, int numpages)
> > +{
> > +	int ret;
> > +
> > +	if (!pat_enabled)
> > +		return set_memory_uc(addr, numpages);
> > +
> > +	ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
> > +			      _PAGE_CACHE_MODE_WT, NULL);
> > +	if (ret)
> > +		goto out_err;
> > +
> > +	ret = _set_memory_wt(addr, numpages);
> > +	if (ret)
> > +		goto out_free;
> > +
> > +	return 0;
> > +
> > +out_free:
> > +	free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
> > +out_err:
> > +	return ret;
> 
> 
> This goto zoo is horrible to read. What's wrong with a straight forward:
> 
> +	if (!pat_enabled)
> +		return set_memory_uc(addr, numpages);
> +
> +	ret = reserve_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE,
> +			      _PAGE_CACHE_MODE_WT, NULL);
> +	if (ret)
> +		return ret;
> +
> +	ret = _set_memory_wt(addr, numpages);
> +	if (ret)
> +		free_memtype(__pa(addr), __pa(addr) + numpages * PAGE_SIZE);
> +	return ret;

Agreed.  I will change set_memory_wc() as well, which is the base of
this function. 

Thanks,
-Toshi


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