Re: [PATCH 2/3] x86: add a is_e820_ram() helper

From: Ingo Molnar <mingo@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	ross.zwisler@linux.intel.com, axboe@kernel.dk,
	boaz@plexistor.com
Subject: Re: [PATCH 2/3] x86: add a is_e820_ram() helper
Date: Thu, 26 Mar 2015 11:04:13 +0100	[thread overview]
Message-ID: <20150326100413.GA19739@gmail.com> (raw)
In-Reply-To: <20150326093424.GA28217@lst.de>

* Christoph Hellwig <hch@lst.de> wrote:

> On Thu, Mar 26, 2015 at 10:02:15AM +0100, Ingo Molnar wrote:
> > This is_e820_ram() factoring out becomes really messy in patch #3.
> > 
> > So you left out a bunch of places making comparisons with E820_RAM, 
> > notably e820_reserve_resources_late() and memblock_x86_fill() - and of 
> > course those have to be left out, otherwise NVRAM might be registered 
> > and used as real kernel RAM!
> > 
> > And this shows the weakness and confusion caused by the factoring out 
> > of is_e820_ram() and then adding E820_PMEM to its definition...
> > 
> > I'd rather you add explicit checks to E820_PMEM (why not E820_PRAM, to 
> > keep in line with the E820_RAM name?), and not lie about 
> > is_e820_ram(). It should result in the exact same end result, with 
> > less confusion.
> > 
> > I have no fundamental objections to the driver otherwise.
> 
> Does this patch (replaces patches 2 and 3) look better to you?

Yeah, the code is much clearer now:

  Acked-by: Ingo Molnar <mingo@kernel.org>

What tree is this intended for? Should I pick up the x86 bits?

Thanks,

	Ingo