From owner-freebsd-questions@freebsd.org Fri Nov 25 15:25:40 2016 Return-Path: Delivered-To: freebsd-questions@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 77EF7C54B43 for ; Fri, 25 Nov 2016 15:25:40 +0000 (UTC) (envelope-from naylor.b.david@gmail.com) Received: from mail-wm0-x233.google.com (mail-wm0-x233.google.com [IPv6:2a00:1450:400c:c09::233]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 0C285209 for ; Fri, 25 Nov 2016 15:25:40 +0000 (UTC) (envelope-from naylor.b.david@gmail.com) Received: by mail-wm0-x233.google.com with SMTP id u144so28233643wmu.1 for ; Fri, 25 Nov 2016 07:25:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:subject:date:message-id:organization:user-agent :mime-version; bh=w6gIU0BvL+WLrRgO6YJvdfO5kW57X+R+riaRsmInGSY=; b=rAKZfgCdQTU6ajFKS5iialuRB5QB/7DjElGk40ppyO7elhynBziZlA2+QEX4ruoups tZvWQyvNpJUh9JtdGE06CCU9+vm6PE7Xf3XXQGN3NjMjUTCbDE1zAhEP/6jfztqso+EI U+Gp9qXWovSHLY2IkYjkvKKP/cwOcwmODLMD/o+PkK5K4h0hC0sPk4HMrCFN2LzA4x+l IGkLKrTBkuUtjwpodCpTkdUhbU7ZBUJb/PeXLpyQm4S2zPbWxu0ZjBOBMplvJRbsu9Ag oX578oUKVUwfyLif4zrehtTNXBO79wQn4lVWOxhI3DT+smHbNQy8qZUZ1wBbgPgnW3gk +jXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:organization :user-agent:mime-version; bh=w6gIU0BvL+WLrRgO6YJvdfO5kW57X+R+riaRsmInGSY=; b=dHSSCzm6IjjagUbml3tbHbcWKENlzdSvXCk2yCizTl7IfDlewxf++Tr10MFXbmXrk/ iu5zlCz/sRCm+cgp+LOgMZIekdIlXLWjiE7/X6qLD7h3SUdlfqh+t1z0Vy90Z7EDmpR7 BZ0w8d7Lty8R56hVMao4ieBQPbQg1OJV55PwTAvzY9rDz7ty+KzQq0jynWeLL/NDPHoi AH42HTDdDnFgnRRWatASVdOsIOyeP7KoZVt22f9FBMOUUDLXXUjJ+yjwh61OXnCGtJae +nFmylsyvO0FqTCVNWwVXQaIObJrquEoN/Uvz2z5hvGo4qodSpSvIMjsHVzTUVBDgN7/ cORA== X-Gm-Message-State: AKaTC0110tR1px6M6HCtr+VEWqcZWaQdDFQiIL0GCbz9KyBYTynBjk5/Q9UTi8zKz7iemw== X-Received: by 10.28.20.70 with SMTP id 67mr7812217wmu.102.1480087538401; Fri, 25 Nov 2016 07:25:38 -0800 (PST) Received: from dragon.local (dsl-246-94-120.telkomadsl.co.za. [41.246.94.120]) by smtp.googlemail.com with ESMTPSA id c187sm13924661wmd.13.2016.11.25.07.25.36 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 25 Nov 2016 07:25:37 -0800 (PST) From: David Naylor To: freebsd-questions@freebsd.org Subject: Memory Barrier Date: Fri, 25 Nov 2016 17:25:34 +0200 Message-ID: <4806733.Z4QWb7OVgq@dragon.local> Organization: Private User-Agent: KMail/4.14.10 (FreeBSD/11.0-RC2; KDE/4.14.10; amd64; ; ) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1901237.3UfmMciAPK"; micalg="pgp-sha512"; protocol="application/pgp-signature" X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Nov 2016 15:25:40 -0000 --nextPart1901237.3UfmMciAPK Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Hi Is there anyway to implement a memory barrier in FreeBSD without using mprotect(2) [1]. Unfortunately, the mprotect(2) method uses mlock(2) and mlock(2) does not always work, depending on load and permissions. I see there was a proposal on a Linux mailing list for a new syscall to implement this functionality [2] but FreeBSD 11.0 does not appear to have it. Regards [1] https://github.com/dotnet/coreclr/blob/master/src/pal/src/thread/process.cpp#L2886 https://github.com/dotnet/coreclr/blob/master/src/pal/src/thread/process.cpp#L2929 [2] https://lkml.org/lkml/2015/7/10/766 --nextPart1901237.3UfmMciAPK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQJ8BAABCgBmBQJYOFfvXxSAAAAAAC4AKGlzc3Vlci1mcHJAbm90YXRpb25zLm9w ZW5wZ3AuZmlmdGhob3JzZW1hbi5uZXQ5NDhFQzUxMUEyN0YwMzAyRTc5OUI1M0FB RDYzRkE4REQ2QjJEQTU1AAoJEK1j+o3WstpVdUAQAMNSI6ckoHjIXXijRW9D63Pl gz6WGfKLX8PxlSbosC5+BVCDLVX35SrAIaGksSbcqy2P/4zXM+3i+sS5wVCPuBRe hNe74c5BYZkXzMJKZ9YzEjslFGoHNegtwYCSZvZ9tnoBnaYeKZcEz4/1J0QJuJ2f 5NU8bh6yWziNfmvF8VF2JSsXZ9gYh8ldJ5/xwav45DPA8BYT2f1nA2qSw/DyYcnZ Z6fZ7pT53Xkys/dwnvMM2m+hpuolDZLDBg5C8UtC1HaWJs14L0CQJPKv9FFw3PrI hD/c3eipKTCD84FZ0jmiL/qH/kmT37RTzG+Y3rrEgvU6FFQlh2y5b50S530h9MIx s/Kh6fMoCftSDwGd7M9UB3OxX7ESPchtwZuDhh7rrSr0Mj87qu4HByiENkyQuRyz /c6029+Mp1vzPjCp4hU+F2LF2HHVCsD/fh1WgJUUfl3t8u7qDiI8yvdG6m8Akd9J VuinvDUdk0ogrQIzJjfIOblfcKmdP+48giUjdldvvVJLDXg68djDqnUTmbNJbMsz yllXNkR0Nj7WKFWazLutZOT2nMPFeAAsZA/u/6NjV/7uw8h335bDrA1MTOhGls3W C13dkLuWarapV/ABSpv1r3BIS6VX5BCZXeAbjlEs/raH9JLsbvVf4KiJOBNpm8D8 nsQ5pD8qVBFEtibNQuuq =H3Yy -----END PGP SIGNATURE----- --nextPart1901237.3UfmMciAPK--