From owner-freebsd-questions@freebsd.org Thu Apr 7 16:57:48 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 A1BE6B080A8 for ; Thu, 7 Apr 2016 16:57:48 +0000 (UTC) (envelope-from matthew@FreeBSD.org) Received: from smtp.infracaninophile.co.uk (smtp.infracaninophile.co.uk [IPv6:2001:8b0:151:1:c4ea:bd49:619b:6cb3]) (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 2C6AC1CD5 for ; Thu, 7 Apr 2016 16:57:48 +0000 (UTC) (envelope-from matthew@FreeBSD.org) Received: from zero-gravitas.local (unknown [85.199.232.226]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: m.seaman@infracaninophile.co.uk) by smtp.infracaninophile.co.uk (Postfix) with ESMTPSA id B726FA845 for ; Thu, 7 Apr 2016 16:57:39 +0000 (UTC) Authentication-Results: smtp.infracaninophile.co.uk; dmarc=none header.from=FreeBSD.org Authentication-Results: smtp.infracaninophile.co.uk/B726FA845; dkim=none; dkim-atps=neutral Subject: Re: AIO in 10.0-RELEASE To: freebsd-questions@freebsd.org References: From: Matthew Seaman Message-ID: <5706918A.2060502@FreeBSD.org> Date: Thu, 7 Apr 2016 17:57:46 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="X90Rsv5I2PNxC7E066v8JrF60bpLT4PwF" X-Virus-Scanned: clamav-milter 0.99.1 at smtp.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, score=-0.4 required=5.0 tests=BAYES_00,RDNS_NONE, SPF_SOFTFAIL autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on smtp.infracaninophile.co.uk X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Apr 2016 16:57:48 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --X90Rsv5I2PNxC7E066v8JrF60bpLT4PwF Content-Type: multipart/mixed; boundary="tem552XPMcDOJDRlMwhePpP1RD71aJtOx" From: Matthew Seaman To: freebsd-questions@freebsd.org Message-ID: <5706918A.2060502@FreeBSD.org> Subject: Re: AIO in 10.0-RELEASE References: In-Reply-To: --tem552XPMcDOJDRlMwhePpP1RD71aJtOx Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 2016/04/07 16:25, Rick Miller wrote: > Hi all, >=20 > A user has been implementing AIO features in an application. They asse= rt > that, despite aio(4) stating that it is enabled either statically (with= > VFS_AIO in the kernel config) or dynamically (kldload), in their > development environment there was no requirement for either of these > methods of enabling AIO. My google-foo is failing me when it comes to > FreeBSD's AIO. >=20 > This question defies logic, but is it possible that AIO works by defaul= t in > earlier versions of 10.0 and not in more recent version of 10.0 without= any > local system changes? >=20 You asked a pretty similar question last month, where one of the replies pointed you to this in the UPDATING file: 20160301: The AIO subsystem is now a standard part of the kernel. The VFS_AIO kernel option and aio.ko kernel module have been removed.= Due to stability concerns, asynchronous I/O requests are only permitted on sockets and raw disks by default. To enable asynchronous I/O requests on all file types, set the vfs.aio.enable_unsafe sysctl to a non-zero value. In fact, that change was *after* 10.3 was branched, so 10.3-RELEASE should behave the same as 10.2 and earlier as far as AIO is concerned. https://svnweb.freebsd.org/base/releng/10.3/UPDATING?revision=3D297262&vi= ew=3Dmarkup As far as I can tell from the manual, calls to aio_read(2) and similar functions should generate an ENOSYS error code, unless your system kernel has the aio module ceither compiled in or loaded. Which runs counter to your user's experience. I suggest asking on freebsd-hackers@... as you're more likely to come to the attention of the responsible developers there. Cheers, Matthew --tem552XPMcDOJDRlMwhePpP1RD71aJtOx-- --X90Rsv5I2PNxC7E066v8JrF60bpLT4PwF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Comment: GPGTools - https://gpgtools.org iQJ8BAEBCgBmBQJXBpGQXxSAAAAAAC4AKGlzc3Vlci1mcHJAbm90YXRpb25zLm9w ZW5wZ3AuZmlmdGhob3JzZW1hbi5uZXQxOUYxNTRFQ0JGMTEyRTUwNTQ0RTNGMzAw MDUxM0YxMEUwQTlFNEU3AAoJEABRPxDgqeTneU8P/2lD6u/yYlPV/40zZwLSwWsp 8vFcp8zOd6VcdvzGwkuMWzu1TDxOy8tfSTkYaKjGHznMAgN+THSwkHFw9BVkFK+F 8XIkj06tbIPNqx5moLX7esEHJve9wDen0UfbGYNYmSBOaVtwoiep2KKAvacPxfdJ FFPUPE3niaQ00oMlD496IPD3PCD1KtLfQ5YjkW8vYk5bVKwyQk3Qg8Ct0IZ//Yt6 aV43M2AdZVOWr2UY494CdTHWA/w8GB/ShdsmMilNhEEpOwtZlTGgLxk1qwRofsKq cZv+B2zDW+K8sOfM/JTZXHvIFo47s/AXeP8W8Ic2UfV0j+DH2j8eFXYbVevs/G6W NAGn+JeNThAQLLrBZmGQ3IbOLzKUCsCsWicGoMROnDNeA/L2q0R+CMtFvSd7C56T +I3iLuH8/iMw+xPL8G4JahjIB/1cYLMoeBJ1PXY+auQ3DXqKHI0vBvjVpi3sNuxX bb+X9fpabPuKfajYEIQs0otX6iEPRZnIqIL8pnvi5v7jLPvc9LAwOLxn/jmnvpDD wfk7L+9wCN8r5VqKtW0jx1M5v+Jv/CXwlWZA7Uo5Q8+8aZ0ZTREeXmgtWLOCVcPk NOI7W8R8Pv8Cj6yeWcE+VHWuxM0Q2nfTlWb5mqywig/4IQ+iGcAkwXzW/y8RRn4+ LhRYfCQG2UaVZlmd+Tvw =bIYy -----END PGP SIGNATURE----- --X90Rsv5I2PNxC7E066v8JrF60bpLT4PwF--