From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: Raid10 multi core scaling Date: Mon, 2 Dec 2013 17:22:07 +1100 Message-ID: <20131202172207.7400e03a@notabene.brown> References: <20131126105859.Horde.-ppIIPYRo99SlH7zGogGx_A@webmail.aeiou.pt> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/1sFYHpflWeQJF__FWLReAI/"; protocol="application/pgp-signature" Return-path: In-Reply-To: <20131126105859.Horde.-ppIIPYRo99SlH7zGogGx_A@webmail.aeiou.pt> Sender: linux-raid-owner@vger.kernel.org To: Pedro Teixeira Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/1sFYHpflWeQJF__FWLReAI/ Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 26 Nov 2013 10:58:59 +0000 Pedro Teixeira wrote: > =C2=A0=C2=A0 I created a Raid10 array with 16 sata 1TB disks and the array > performance > seems to be limited by the md0_raid10 taking 99% of one core and not > scalling to other cores. I tried overclocing the cpu cores and this lead = to > a small increase in performance ( but md0_raid10 keeps eating 99% of one > core ). Are you really talking about general array performance, or just resync performance? Because md0_raid10 doesn't do much work for normal IO so that should scale = to multiple processors. I'm not sure that optimising resync to use more than one processor is really much of a priority - is it? NeilBrown >=20 > =C2=A0 =C2=A0I'm using: > =C2=A0 =C2=A0=C2=A0- a phenom X6 at 3600mhz > =C2=A0 =C2=A0=C2=A0- 16 seagate SSHDs ( sata3 7200RPM with 8GB ssd cache ) > =C2=A0 =C2=A0=C2=A0- 4x marvell 9230 sata3 controllers ( 4 ports each ) p= cie 2.0 2x > lanes. > =C2=A0 =C2=A0=C2=A0- 8GB ram > =C2=A0 =C2=A0=C2=A0- custom 3.12 kernel and mdadm compiled from latest so= urce >=20 > =C2=A0 =C2=A0what I did to test performance was to force a check on the a= rray, and > this > leads to mdadm reporting a speed of about 990000K/sec. The hard disks > report a 54% utilization. ( Overclocking the cpu by 200mhz increases the > resync speed a bit and the hdd's utilizartion to about 58% ) >=20 > =C2=A0 =C2=A0If I do the same with a raid5 array instead of raid10, them = resync > speed > will be almost double of raid10, the harddisk utilization reported will be > 98-100% and I can see at least two cores being used. >=20 > _________________________________________________________________________= _______ > Mensagem enviada atrav=C3=A9s do email gr=C3=A1tis AEIOU > http://www.aeiou.pt > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html --Sig_/1sFYHpflWeQJF__FWLReAI/ Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIVAwUBUpwnDznsnt1WYoG5AQKJ0hAAspPTraAvhGhygW0rqQExzPq2oeTIPMHa 7vXvfIFeLFvmY2w/tX5o8zCayrTWBLFxYFyX7Kl4IeEAQB/vYhKxQqZJTiNhSeA+ 2ZxPaoMgrUSuhXUKpAq0nahZhdbeJwmvkl45ogsf3YwsaDdapF1W6REL47z8l3Rz QCpeGAuUTSVLz9cOvqSF2Nw8Svi1I2ZvwmQrHqSAJQDZznkUXazMdjKT4ibysreM Txyd4qKPip/Nm8e47VkBdKetwnf0VniCRGCqo5JG7kmSl+e8A9hBgpM7IZnI14WB Y6QyzvJil2i2PQ49LO0ebNnIp9Sd5dT8pV5xiUbJIe4tXJGSVfnGuJkJATqezdNr f1jWP62TSXt/hlpODJ6Srz155zUdvfMc50K2IRTuq88MaQVN0CbytiQnMUsEPqCq GUUa76K78Q7TbxqQmTlRI4bdYhlk3CHZHEwrlxkS885uPK++0pyooLdqEZOmV0Ug RFnceqgT6g/z1wekMLko9SbneSrEbJx+Uyb3MOiIrWxF6TTxBoD2w5MQJIynyTOY OcifOcU9ssle89nTTQGT0FMgx5enPceRIrMVqSEkmFfOxMgoqT8i45LLD6KxuDig dETOe/gUzcSam5LvAKESlNxbBwMNXkRNgj2r9qQ451ooaN+bTyJH0RZmnFt94HBS tVgNY8QJ9XA= =o2i7 -----END PGP SIGNATURE----- --Sig_/1sFYHpflWeQJF__FWLReAI/--