Date: Tue, 7 Apr 2015 09:04:53 +0200
From: Christoph Hellwig <hch@lst.de>
To: Boaz Harrosh <boaz@plexistor.com>
Cc: Toshi Kani <toshi.kani@hp.com>, mingo@redhat.com, hpa@zytor.com,
        tglx@linutronix.de, linux-nvdimm@ml01.01.org,
        linux-fsdevel@vger.kernel.org, x86@kernel.org,
        linux-kernel@vger.kernel.org, hch@lst.de,
        Yinghai Lu <yinghai@kernel.org>
Subject: Re: [PATCH v2] x86: Revert E820_PRAM change in e820_end_pfn()
Message-ID: <20150407070453.GB7074@lst.de>
References: <1428346839-11997-1-git-send-email-toshi.kani@hp.com> <55237AF5.3050005@plexistor.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <55237AF5.3050005@plexistor.com>
User-Agent: Mutt/1.5.17 (2007-11-01)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1753
Lines: 37

On Tue, Apr 07, 2015 at 09:36:37AM +0300, Boaz Harrosh wrote:
> On 04/06/2015 10:00 PM, Toshi Kani wrote:
> > 'Commit ec776ef6bbe17 ("x86/mm: Add support for the non-standard
> > protected e820 type")' added E820_PRAM ranges, which do not have
> > have struct-page.  Therefore, there is no need to update max_pfn
> > to cover the E820_PRAM ranges.  
> 
> But E820_PRAM ranges will have the possibility for struct-page.
> 
> That said I have tested with this patch +  struct-page and

I'd love to resurrect the old "real page backed" pmem support from
the old Intel patches eventually, but with all the arguments on
how we should do I/O on pmem I'd like to keep that a ѕeparate
discussion.  And leaving only fragments of some support in is a bad
idea, so sorry for letting all this slip through..

> > -static unsigned long __init e820_end_pfn(unsigned long limit_pfn)
> > +static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
> 
> Why don't you rename it to say e820_max_ram_pfn or something with ram
> as you noted, and drop the @type. As Christoph said it is very ugly. You do not
> put an extra parameter because of a bad name?
> 
> Anyway you are changing all call sites so it will not even be a bigger
> change

It's a static function, and we have much worse naming sins in public
ones, so I'm not worried about a _ram more or less.  But if people feel
stronly about it I'm fine with adding the _ram.

I feel pretty stronly against adding back a pointless argument, though.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/