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Date: Thu, 15 May 2014 10:05:05 +0300
From: Oren Twaig <oren@scalemp.com>
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To: Anthony Iliopoulos <anthony.iliopoulos@huawei.com>,
        Dave Hansen <dave@sr71.net>
CC: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Shay Goikhman <shay.goikhman@huawei.com>,
        Paul Mundt <paul.mundt@huawei.com>,
        Carlos Villavieja <villavieja@hps.utexas.edu>,
        Nacho Navarro <nacho.navarro@bsc.es>,
        Avi Mendelson <avi.mendelson@tce.technion.ac.il>,
        Yoav Etsion <yetsion@tce.technion.ac.il>,
        Gerald Schaefer <gerald.schaefer@de.ibm.com>,
        David Gibson <david@gibson.dropbear.id.au>,
        linux-arch <linux-arch@vger.kernel.org>
Subject: Re: [PATCH] x86, hugetlb: add missing TLB page invalidation for hugetlb_cow()
References: <20140514092948.GA17391@server-36.huawei.corp> <5372A067.9010808@sr71.net> <20140515170035.GA15779@server-36.huawei.corp>
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On 05/15/2014 08:00 PM, Anthony Iliopoulos wrote:
> I have dismissed this case, since I assume that there are many more
> cycles spent in servicing the TLB invalidation IPI, walking the pgtable
> plus other related overhead (e.g. sched) than in updating the pte/pmd
> so I am not sure how possible it would be to hit this condition.

Hi Anthony,

I have a question about the above statement. What will happen with multi
cpu VMs ? won't the race described above can happen ? I.e one virtual CPU
can will visit the host and the other will continue to encounter your race ?

Thanks,
Oren.