From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx198.postini.com [74.125.245.198]) by kanga.kvack.org (Postfix) with SMTP id 540A86B009E for ; Thu, 15 Nov 2012 03:45:33 -0500 (EST) Date: Thu, 15 Nov 2012 10:46:35 +0200 From: "Kirill A. Shutemov" Subject: Re: [PATCH v5 05/11] thp: change_huge_pmd(): keep huge zero page write-protected Message-ID: <20121115084635.GC9676@otc-wbsnb-06> References: <1352300463-12627-1-git-send-email-kirill.shutemov@linux.intel.com> <1352300463-12627-6-git-send-email-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="/Uq4LBwYP4y1W6pO" Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: Andrew Morton , Andrea Arcangeli , linux-mm@kvack.org, Andi Kleen , "H. Peter Anvin" , linux-kernel@vger.kernel.org, "Kirill A. Shutemov" --/Uq4LBwYP4y1W6pO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Nov 14, 2012 at 03:12:54PM -0800, David Rientjes wrote: > On Wed, 7 Nov 2012, Kirill A. Shutemov wrote: >=20 > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > > index d767a7c..05490b3 100644 > > --- a/mm/huge_memory.c > > +++ b/mm/huge_memory.c > > @@ -1259,6 +1259,8 @@ int change_huge_pmd(struct vm_area_struct *vma, p= md_t *pmd, > > pmd_t entry; > > entry =3D pmdp_get_and_clear(mm, addr, pmd); > > entry =3D pmd_modify(entry, newprot); > > + if (is_huge_zero_pmd(entry)) > > + entry =3D pmd_wrprotect(entry); > > set_pmd_at(mm, addr, pmd, entry); > > spin_unlock(&vma->vm_mm->page_table_lock); > > ret =3D 1; >=20 > Nack, this should be handled in pmd_modify(). I disagree. It means we will have to enable hzp per arch. Bad idea. What's wrong with the check? --=20 Kirill A. Shutemov --/Uq4LBwYP4y1W6pO Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQpKvrAAoJEAd+omnVudOMbAIQALQYjNB3Ykp89rdxhWu5HWvV qp0eBB9WHuD3AK9ezQVWFY8jKijlxELc/NPbJStlfe5PMSkYtUkpl3Iju8n3khd0 BUA1tSrdLOnAW3efpisTN9BvBP+0mPrY9TynPGuYDjO2qFOOLoXNYqUmeE9GmVFv HGVcfxQ4I2331qFr9m35+/Wt4W/Fe+QqIDsQ725ESr8YFDNcyp4wKXo2roZER4+h nT27KQmktCyTNlu9htYecHKR3RgonxUyoWd4WRlo+ofWiJhVdQP92QcQuQUgS56u 46UG9S+vDcs5TaJUg/T7RuFNLylUuq3S192NTs29Ou7EqTwWw13o+DjRmP24reRS VutQaklLFcW6dKUW79rk8f/6WUPgjGfk2eF4Ix6ceR0CaxA8EjZPcWoWb1orob+M mf4qTt0wXURcF3wvgS7S1eI7bi/8z+x+bjWVNPF1gHZAeUDsalN+NWeT6Lk2pil0 mIgjeLBBnrhHRppgpWFZaqaIqPDxjsmA6bMcHzpZyG/zfHhj10McdT24Olyh0tbr 8zHXZSA2X7R/V4nrgp6/UM7Vx+36b6FEYZBBMs8rSsoYj0H4DaXRBrECInbXATEq Nv+qeuUnB5D3B8e9V1bilTii57JXIcTozsJMUSVBW6yuTm5IVFPSpbQsHb7QzFAp z6rStm5r0x2rRYIGSnw0 =eKdr -----END PGP SIGNATURE----- --/Uq4LBwYP4y1W6pO-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org