From owner-freebsd-arm@freebsd.org Fri Dec 28 20:22:28 2018 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 9DEA814213A4 for ; Fri, 28 Dec 2018 20:22:28 +0000 (UTC) (envelope-from marklmi@yahoo.com) Received: from sonic303-22.consmr.mail.ne1.yahoo.com (sonic303-22.consmr.mail.ne1.yahoo.com [66.163.188.148]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id B998F69EDE for ; Fri, 28 Dec 2018 20:22:27 +0000 (UTC) (envelope-from marklmi@yahoo.com) X-YMail-OSG: owz7Eb8VM1nKZuEr0GgzRC_8Xh7cV3NmPnLnIUUqh58HomsqS6LvefDXXWwRvBB 3fDcM6t_u2I_URGoEsuzttcInBx1VudXdi3db27HCySFzrbYuZKn7Jet6krhrIq5qvEjH1BcHp3R CwFkADlEz6lDPLSOjGk22lz47uIB2VeA0DqlrDrc4afscwDyC1v8gcXT5aYfgnCDLKl8_Fj5pmQk YcgQdBkHllcdPwU36yk8j9GhJ1xeu7508eOfOJknWKDhSQ9AfruXmw6XT.O.mFxzh1GugsvTO_xP qaBTM3KhYmYxW1TXXV4pU7oRwvK4MUai1WOWEOCEOE66ROgtU05ZbfBF_0Nn32PwHpvWd_b2qCgG GnGCes_dSG7_TNCsZVmOTbsygk2vYBD8YADyB31Zfo7j8qB..laZlCmvvJwL5WLW5XoGsz5ak_9P vqzDbQw8EXkt9zVfZ3KfnOM06NALZ039gXGSgwrC._L98HIqQlamxqdXl.aDtvaAls5fA1mEGIH9 Z5j13SlsRDJSv4Yo1ZnZgv3UOmdTWwJhxeLl2.tjEGcfgPQPIpgw5W7AIzQ3JmFu051X7NPyeZu6 wV_ZQF9tf3i_kXHR6eDTRMnEMdEK0b1Bw6eJtrWIAHRV2dSKKUlG8M9HV39fmBoeCXJJS2AOH0mO vjrOucv0UcoiqwvhXPvFiNeaQaE3OcqweNJpmjcIfpZg.wyl2nxVb.gf3sWBlIgxgEDvSTohA2IQ kGCYYCxyW.o6.y1hjlqBhe3lW_AwBp3uUWULjVOu7LtJ46jB6_zAqGJvhvVdpueR8x4_PbXtDEGo YAmuUX1_T7qzB7z1uktlwKYwT47MkixO2knoOJZBLGQ4mll.OPwWghAx0wq4dMIhVs0yiZ4SQBBo HSdeG8gtLEI7Bpr_u.DyG05TPfKeznMIZW0R_d8W.ynbNsIR3iFdTRMx_K1wLnhk2J2yDmwVs9XY gy3p3mWHbr_3e6VQ7l4ic3bnmlHVKun8ZF87U6xnp7wp8kS825Qo6i044kI_PAFIpPaEOZAgMNW1 VFvhAhv5gBliwan.34rCeLTHwVEPEnYZubFBFF.yTmF2bhZ7uV.nFt_MpSFgyH5eG6jCM Received: from sonic.gate.mail.ne1.yahoo.com by sonic303.consmr.mail.ne1.yahoo.com with HTTP; Fri, 28 Dec 2018 20:22:20 +0000 Received: from c-67-170-167-181.hsd1.or.comcast.net (EHLO [192.168.1.109]) ([67.170.167.181]) by smtp429.mail.ne1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID b8b32a4346149f25d8f944b89459e9c7; Fri, 28 Dec 2018 20:12:08 +0000 (UTC) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: Re: A reliable port cross-build failure (hangup) in my context (amd64->armv7 cross build, with native-tool speedup involved) From: Mark Millard In-Reply-To: <13f5e4dd-33fb-2170-e31a-1b5d5f155869@freebsd.org> Date: Fri, 28 Dec 2018 12:12:06 -0800 Cc: freebsd-emulation@freebsd.org, FreeBSD Current , ports-list freebsd , freebsd-arm , FreeBSD Toolchain Content-Transfer-Encoding: quoted-printable Message-Id: References: <865A13C8-9749-486E-9F79-5EEDDECBE621@yahoo.com> <0154C3AC-D85B-4FCF-BA63-454BC26BC1A2@yahoo.com> <13f5e4dd-33fb-2170-e31a-1b5d5f155869@freebsd.org> To: mmel@freebsd.org X-Mailer: Apple Mail (2.3445.102.3) X-Rspamd-Queue-Id: B998F69EDE X-Spamd-Bar: / X-Spamd-Result: default: False [0.34 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ptr:yahoo.com]; MV_CASE(0.50)[]; FREEMAIL_FROM(0.00)[yahoo.com]; RCPT_COUNT_FIVE(0.00)[6]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[yahoo.com:+]; MX_GOOD(-0.01)[cached: mta6.am0.yahoodns.net]; DMARC_POLICY_ALLOW(-0.50)[yahoo.com,reject]; FROM_EQ_ENVFROM(0.00)[]; RCVD_TLS_LAST(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[yahoo.com]; ASN(0.00)[asn:36646, ipnet:66.163.184.0/21, country:US]; MID_RHS_MATCH_FROM(0.00)[]; DWL_DNSWL_NONE(0.00)[yahoo.com.dwl.dnswl.org : 127.0.5.0]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.18)[-0.177,0]; R_DKIM_ALLOW(-0.20)[yahoo.com:s=s2048]; FROM_HAS_DN(0.00)[]; NEURAL_SPAM_SHORT(0.77)[0.769,0]; NEURAL_HAM_LONG(-0.79)[-0.786,0]; MIME_GOOD(-0.10)[text/plain]; IP_SCORE(1.04)[ip: (3.21), ipnet: 66.163.184.0/21(1.16), asn: 36646(0.93), country: US(-0.08)]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[148.188.163.66.list.dnswl.org : 127.0.5.0]; RWL_MAILSPIKE_POSSIBLE(0.00)[148.188.163.66.rep.mailspike.net : 127.0.0.17] X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Dec 2018 20:22:28 -0000 On 2018-Dec-28, at 05:13, Michal Meloun = wrote: > Mark, > this is known problem with qemu-user-static. > Emulation of every single interruptible syscall is broken by design = (it > have signal related races). Theses races cannot be solved without = major > rewrite of syscall emulation code. > Unfortunately, nobody actively works on this, I think. >=20 Thanks for the note setting some expectations. On the evidence that I have I expect that more is going on than that: A) The hang-up always happens and always in the same place. So it would appear that no race is involved. B) (A) is true even for varying the number of builders in parallel (so other builds also happening) and the number of jobs allowed per builder. It also fails for only one builder allowed only one process. (I get traces from that last kind of context.) C) The problem started on the package-building servers for armv7 and armv6 without qemu-user-static having an update (FreeBSD and cmake had updates, for example). D) The problem is only observed for targeting armv7 and armv6 as far as I can tell. I've never seen it for aarch64, neither my own builds nor when I looked at the package-building server history. At least that is what got me started. (I've since learned that qemu-user-static uses fork in place of a requested vfork.) My ktrace/kdump experiment yesterday showed something odd for the kevent that hangs in cmake: 93172 qemu-arm-static CALL = kevent(0x3,0x7ffffffe7d40,0x2,0x7ffffffd7d40,0x400,0) 93172 qemu-arm-static STRU struct kevent[] =3D { { ident=3D6, = filter=3DEVFILT_READ, flags=3D0x1, fflags=3D0, data=3D0, = udata=3D0x0 } { ident=3D0x0, filter=3D, flags=3D0, = fflags=3D0x8, data=3D0x1ffff, udata=3D0x0 } } Note the 0x2 argument to kevent and the apparently-odd 2nd entry in the = struct kevent[]. The kevent use is from cmake. So far I've not identified a signal being delivered at a time that would = seem to me to be likely to contribute. (But this is not familiar code so my = judgment is likely not the best.) Note: I normally run FreeBSD using a non-debug kernel, even when using head. (The kernel does have symbols.) =3D=3D=3D Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)