Message-Id: <5215D99102000078000ED838@nat28.tlf.novell.com>
Date: Thu, 22 Aug 2013 08:27:45 +0100
From: "Jan Beulich" <JBeulich@suse.com>
To: "Cyrill Gorcunov" <gorcunov@gmail.com>
Cc: "Andy Lutomirski" <luto@amacapital.net>,
        "David Vrabel" <david.vrabel@citrix.com>,
        "Andrew Morton" <akpm@linux-foundation.org>,
        "Linus Torvalds" <torvalds@linux-foundation.org>,
        <Xen-devel@lists.xen.org>,
        "Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
        "Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
        "Pavel Emelyanov" <xemul@parallels.com>,
        "Ingo Molnar" <mingo@redhat.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: Regression: x86/mm: new _PTE_SWP_SOFT_DIRTY bit conflicts
 with existing use
References: <5214C524.1050900@citrix.com> <20130821141223.GS18673@moon>
 <5214F09002000078000ED5C3@nat28.tlf.novell.com>
 <20130821154238.GV18673@moon>
 <521500E102000078000ED65C@nat28.tlf.novell.com>
 <20130821161946.GW18673@moon>
 <5215D23A02000078000ED7FC@nat28.tlf.novell.com>
 <20130822070305.GH18673@moon>
In-Reply-To: <20130822070305.GH18673@moon>
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>>> On 22.08.13 at 09:03, Cyrill Gorcunov <gorcunov@gmail.com> wrote:
> Ok, how about this?
> 
> static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
> {
> 	BUG_ON(pte_present(pte));
> 	return pte_set_flags(pte, _PAGE_SWP_SOFT_DIRTY);
> }

Sure, fine with me. Perhaps VM_BUG_ON() or some other similar
construct limiting the scope when any extra code gets generated
would do too.

But as said, even better would perhaps be to have it act on a
swp_entry_t.

Jan

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