Date: Fri, 15 Sep 2017 11:18:40 -0400 From: Nikolai Lifanov <lifanov@FreeBSD.org> To: allanjude@FreeBSD.org Cc: freebsd-current@freebsd.org Subject: Re: Time to increase MAXPHYS? Message-ID: <bdcfce17-4cbf-70d0-c78b-a73b0dfde648@FreeBSD.org> In-Reply-To: <3719c729-9434-3121-cf52-393a4453d0b2@freebsd.org> References: <0100015c6fc1167c-6e139920-60d9-4ce3-9f59-15520276aebb-000000@email.amazonses.com> <972dbd34-b5b3-c363-721e-c6e48806e2cd@elischer.org> <3719c729-9434-3121-cf52-393a4453d0b2@freebsd.org>
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This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --ECLU8prB6Un7pB8OLocBThOpcIkjEPxKT Content-Type: multipart/mixed; boundary="rHFlLT9CQi9OogUgGUTqXnVXHBeiMWdkE"; protected-headers="v1" From: Nikolai Lifanov <lifanov@FreeBSD.org> To: allanjude@FreeBSD.org Cc: freebsd-current@freebsd.org Message-ID: <bdcfce17-4cbf-70d0-c78b-a73b0dfde648@FreeBSD.org> Subject: Re: Time to increase MAXPHYS? References: <0100015c6fc1167c-6e139920-60d9-4ce3-9f59-15520276aebb-000000@email.amazonses.com> <972dbd34-b5b3-c363-721e-c6e48806e2cd@elischer.org> <3719c729-9434-3121-cf52-393a4453d0b2@freebsd.org> In-Reply-To: <3719c729-9434-3121-cf52-393a4453d0b2@freebsd.org> --rHFlLT9CQi9OogUgGUTqXnVXHBeiMWdkE Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 6/3/17 11:55 PM, Allan Jude wrote: > On 2017-06-03 22:35, Julian Elischer wrote: >> On 4/6/17 4:59 am, Colin Percival wrote: >>> On January 24, 1998, in what was later renumbered to SVN r32724, dyso= n@ >>> wrote: >>>> Add better support for larger I/O clusters, including larger physica= l >>>> I/O. The support is not mature yet, and some of the underlying >>>> implementation >>>> needs help. However, support does exist for IDE devices now. >>> and increased MAXPHYS from 64 kB to 128 kB. Is it time to increase i= t >>> again, >>> or do we need to wait at least two decades between changes? >>> >>> This is hurting performance on some systems; in particular, EC2 "io1"= >>> disks >>> are optimized for 256 kB I/Os, EC2 "st1" (throughput optimized >>> spinning rust) >>> disks are optimized for 1 MB I/Os, and Amazon's NFS service (EFS) >>> recommends >>> using a maximum I/O size of 1 MB (and despite NFS not being *physical= * >>> I/O it >>> seems to still be limited by MAXPHYS). >>> >> We increase it in freebsd 8 and 10.3 on our systems, Only good result= s. >> >> sys/sys/param.h:#define MAXPHYS (1024 * 1024) /* max raw I/O= >> transfer size */ >> >> _______________________________________________ >> freebsd-current@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-current >> To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.= org" >=20 > At some point Warner and I discussed how hard it might be to make this = a > boot time tunable, so that big amd64 machines can have a larger value > without causing problems for smaller machines. >=20 > ZFS supports a block size of 1mb, and doing I/Os in 128kb negates some > of the benefit. >=20 > I am preparing some benchmarks and other data along with a patch to > increase the maximum size of pipe I/O's as well, because using 1MB > offers a relatively large performance gain there as well. >=20 Hi! I also migrated to 1mb recordsize. What's the status of your patches and/or making MAXPHYS a boot-time tunable? I can help test these. - Nikolai --rHFlLT9CQi9OogUgGUTqXnVXHBeiMWdkE-- --ECLU8prB6Un7pB8OLocBThOpcIkjEPxKT Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQJIBAEBCAAyFiEE5oT6TcuaWvG5gtjzZ6sv56ecR0UFAlm771AUHGxpZmFub3ZA ZnJlZWJzZC5vcmcACgkQZ6sv56ecR0WTZhAAt8y0JeghS7+EAmBDIJ/AojjaMr1X rXUvFR+Sc59m3LCQxrXf7gjaB0VG7K+2m39/ky5dI524gnvw0QtWw5Ge2GkyqIEM NMEUouV6n4sYrttC5VAcb0IB9gfV6D0NaUZqFILZrEUBw6prxjU9xx2k8yt/meVJ WbdG/Ci6R3t9TiHY/k5QlPqLwYmQ5cg1mtPw1tawhZxCMd/z8izqZsi6MAKY3tTi XLULXnD0xjbL6SUnxzy26DHeSHeqdAViAThgqj7KbrOUavCtwIJvuR7fRl6vO4Us BHWHsbq9SDk1Ol9QyFyaQ2cpz6I0cwkE/hqBtGn96tZgIVWH5vI29GgreHdNfNYo nFWxGdjvwfqVaLsHySZfIV/C2cCFjC9HxyatgmGk3idwApepbD72Ezn7YUda7PdJ r82Qf/nmTU+R1cTmqfQcTdVJduLpVol9wyiSpkkX2QVSiwrMVHCwDGohnI20vrhj SBMLLVPyu8VWbs96s3AufP5GMmOCfowK8tKNCVYYu1Lbqu7lUIj834Hu2EhMN+uK xVuhu+XgmrdDG6Zqh8lZ3OI92smRdvrdmESp11N4LJIzaU56wXUdVwR3wyGfV/Yo H6DZYYti9Y/FNJkVA/LbXz0vno62rw+1F4x6QhYoOPdRMf5/vxZxi7vv41AhFJdQ MHo/d5ebTEUFWYg= =mSaT -----END PGP SIGNATURE----- --ECLU8prB6Un7pB8OLocBThOpcIkjEPxKT--
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