From owner-freebsd-arm@freebsd.org Mon Apr 10 00:10:13 2017 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A3712D36D84 for ; Mon, 10 Apr 2017 00:10:13 +0000 (UTC) (envelope-from markmi@dsl-only.net) Received: from asp.reflexion.net (outbound-mail-210-4.reflexion.net [208.70.210.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 49245AA7 for ; Mon, 10 Apr 2017 00:10:12 +0000 (UTC) (envelope-from markmi@dsl-only.net) Received: (qmail 21417 invoked from network); 10 Apr 2017 00:11:11 -0000 Received: from unknown (HELO mail-cs-01.app.dca.reflexion.local) (10.81.19.1) by 0 (rfx-qmail) with SMTP; 10 Apr 2017 00:11:11 -0000 Received: by mail-cs-01.app.dca.reflexion.local (Reflexion email security v8.40.0) with SMTP; Sun, 09 Apr 2017 20:10:11 -0400 (EDT) Received: (qmail 24322 invoked from network); 10 Apr 2017 00:10:10 -0000 Received: from unknown (HELO iron2.pdx.net) (69.64.224.71) by 0 (rfx-qmail) with (AES256-SHA encrypted) SMTP; 10 Apr 2017 00:10:10 -0000 Received: from [192.168.1.106] (c-76-115-7-162.hsd1.or.comcast.net [76.115.7.162]) by iron2.pdx.net (Postfix) with ESMTPSA id 46C38EC7901; Sun, 9 Apr 2017 17:10:10 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: The arm64 fork-then-swap-out-then-swap-in failures: a program source for exploring them From: Mark Millard In-Reply-To: <8FFE95AA-DB40-4D1E-A103-4BA9FCC6EDEE@dsl-only.net> Date: Sun, 9 Apr 2017 17:10:09 -0700 Cc: andrew@freebsd.org, freebsd-hackers@freebsd.org, freebsd-arm Content-Transfer-Encoding: quoted-printable Message-Id: <89D6D677-3BE2-45E2-A902-CC6A0305F3F9@dsl-only.net> References: <4DEA2D76-9F27-426D-A8D2-F07B16575FB9@dsl-only.net> <163B37B0-55D6-498E-8F52-9A95C036CDFA@dsl-only.net> <08E7A5B0-8707-4479-9D7A-272C427FF643@dsl-only.net> <20170409122715.GF1788@kib.kiev.ua> <9D152170-5F19-47A2-A06A-66F83CA88A09@dsl-only.net> <9DCAF95B-39A5-4346-88FC-6AFDEE8CF9BB@dsl-only.net> <8FFE95AA-DB40-4D1E-A103-4BA9FCC6EDEE@dsl-only.net> To: Konstantin Belousov X-Mailer: Apple Mail (2.3273) X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Apr 2017 00:10:13 -0000 On 2017-Apr-9, at 10:24 AM, Mark Millard wrote: > On 2017-Apr-9, at 5:27 AM, Konstantin Belousov = wrote: >=20 >> Hmm, could you try the following patch, I did not even compiled it. >=20 > I'll try it later today. >=20 >> diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c >> index 3d5756ba891..55aa402eb1c 100644 >> --- a/sys/arm64/arm64/pmap.c >> +++ b/sys/arm64/arm64/pmap.c >> @@ -2481,6 +2481,11 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, = vm_offset_t eva, vm_prot_t prot) >> sva +=3D L3_SIZE) { >> l3 =3D pmap_load(l3p); >> if (pmap_l3_valid(l3)) { >> + if ((l3 & ATTR_SW_MANAGED) && >> + pmap_page_dirty(l3)) { >> + vm_page_dirty(PHYS_TO_VM_PAGE(l3 = & >> + ~ATTR_MASK)); >> + } >> pmap_set(l3p, ATTR_AP(ATTR_AP_RO)); >> PTE_SYNC(l3p); >> /* XXX: Use pmap_invalidate_range */ Preliminary testing indicates that this fixes the some-pages-become-zero problem for fork-then-swapout/in. Thanks! I'll see if a buildworld can go through without being stopped by the type of issue. But that will take a while. (It is how I originally ran into the problem(s) that others had been reporting on the lists.) Side notes: The decreasing-RES(ident memory) behavior was unchanged. The "child gets only 80K RES initially" behavior was also unchanged. (These are as shown by "top -PCwaopid" . These are just differences with what I see for other TARGET_ARCH's.) =3D=3D=3D Mark Millard markmi at dsl-only.net