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Date: Sun, 10 Jan 2016 09:08:51 +0800
From: Minfei Huang <mhuang@redhat.com>
To: Xunlei Pang <xlpang@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>, kexec@lists.infradead.org,
        linux-kernel@vger.kernel.org, ebiederm@xmission.com,
        akpm@linux-foundation.org, Dave Young <dyoung@redhat.com>,
        Vivek Goyal <vgoyal@redhat.com>
Subject: Re: [PATCH v3 2/2] kexec: Provide
 arch_kexec_protect(unprotect)_crashkres()
Message-ID: <20160110010851.GA19773@dhcp-128-25.nay.redhat.com>
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On 01/08/16 at 09:28pm, Xunlei Pang wrote:
> On 01/08/2016 at 04:47 PM, Minfei Huang wrote:
> > On 01/08/16 at 10:33am, Xunlei Pang wrote:
> >> +
> >> +static int
> >> +kexec_mark_range(unsigned long start, unsigned long end, bool protect)
> >> +{
> >> +	struct page *page;
> >> +	unsigned int nr_pages;
> >> +
> >> +	/* For physical range: [start, end] */
> >> +	if (!end || start > end)
> >> +		return 0;
> > This test !end is hard to be understood without the annotation. It is
> > better to add the comment about it.
> 
> !end is just for uninitialized crashk resource with a zero end member,
> maybe not so hard to understand :-)

Yes, The test !end may be simple, if someone knows the logic of kexec.
But it's hard to be understood, if there is only a glance from someone
without any annotation.

This test !end is related to the specific code flow, so it is better to
annotate it.

Thanks
Minfei

> 
> Regards,
> Xunlei
> 
> >
> > Otherwise it looks good for me.