From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993035Ab2KOJbF (ORCPT ); Thu, 15 Nov 2012 04:31:05 -0500 Received: from mga03.intel.com ([143.182.124.21]:30203 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755946Ab2KOJbD (ORCPT ); Thu, 15 Nov 2012 04:31:03 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.83,255,1352102400"; d="asc'?scan'208";a="168670006" Date: Thu, 15 Nov 2012 11:32:09 +0200 From: "Kirill A. Shutemov" 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" Subject: Re: [PATCH v5 08/11] thp: setup huge zero page on non-write page fault Message-ID: <20121115093209.GF9676@otc-wbsnb-06> References: <1352300463-12627-1-git-send-email-kirill.shutemov@linux.intel.com> <1352300463-12627-9-git-send-email-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="R6sEYoIZpp9JErk7" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --R6sEYoIZpp9JErk7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Nov 14, 2012 at 03:33:16PM -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 f36bc7d..41f05f1 100644 > > --- a/mm/huge_memory.c > > +++ b/mm/huge_memory.c > > @@ -726,6 +726,16 @@ int do_huge_pmd_anonymous_page(struct mm_struct *m= m, struct vm_area_struct *vma, > > return VM_FAULT_OOM; > > if (unlikely(khugepaged_enter(vma))) > > return VM_FAULT_OOM; > > + if (!(flags & FAULT_FLAG_WRITE)) { > > + pgtable_t pgtable; > > + pgtable =3D pte_alloc_one(mm, haddr); > > + if (unlikely(!pgtable)) > > + goto out; >=20 > No use in retrying, just return VM_FAULT_OOM. Hm. It's consistent with non-hzp path: if pte_alloc_one() in __do_huge_pmd_anonymous_page() fails __do_huge_pmd_anonymous_page() returns VM_FAULT_OOM which leads to "goto out". Should it be fixed too? >=20 > > + spin_lock(&mm->page_table_lock); > > + set_huge_zero_page(pgtable, mm, vma, haddr, pmd); > > + spin_unlock(&mm->page_table_lock); > > + return 0; > > + } > > page =3D alloc_hugepage_vma(transparent_hugepage_defrag(vma), > > vma, haddr, numa_node_id(), 0); > > if (unlikely(!page)) { --=20 Kirill A. Shutemov --R6sEYoIZpp9JErk7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQpLaZAAoJEAd+omnVudOMd2UP/2a0TlYQG+m0yNRbGoFpV9EB n6VTm/l8RbmQM9EXsYG8V0gaUxQvFPwuyEY4xxvd7CBlPz4CBcQA8s8hSuIlLyxX zbeDzUficvPQPWWCKb0l5K/ASa8+4WRdMCr7mot1fq3Az5cdDbluOTtdQqF3pr2W xhK6T26DPKxUSBjExdPS1i30V3UQfurJFDmKs7FB6hg8Svrd8G9DXyNTZA5XJZSW JDh2YGP3A8L/XU89LcwsxIL8q7xebvCY+onGVxZipPkzLfkLFfYX9x+Gz+Iobi8t 5qnWdDwY4i+Yg9Z4MnaR+8ZE9J/VO2mHmE41TJg8wDmQ6t+x0fVhNeJwBJh2R26S 1HP6XiE15drc8VY//0Nj0Cpyh93YRo4wif/mxdlWQaY9HYJaIYTsc23mr0MXXrgO HnQJKNedowhW5df1n6usPbUd79YFuN6IrtCDEZY50J1+9XhCpiPfH+FBLTTo7W+J emuFuOw7Mp3asO43SoNyq94pvQ9aJMBdeKRI1GCmf/MitcwxaGyaGq/YyHwic4CS 2mNWO4T7SaVYOde9SlATkEBNGyppH0jtzsgzcICUwdP+5w937VcNqqW2TD1LSC3d E/ba0czRfmY2AGlXviV3qnMm6yWyF1ejQkMsSfHNxF0huOkxilLRIMrDhc2QyspT 7OhzpBozUYmAAIjk7YlX =dJsM -----END PGP SIGNATURE----- --R6sEYoIZpp9JErk7--