From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikola Ciprich Subject: Re: 3.0.12 - unregister_pernet_gen_subsys hogging whole system Date: Thu, 22 Dec 2011 22:52:46 +0100 Message-ID: <20111222215246.GA2694@nik-comp.lan> References: <20111222151908.GA11020@pcnci.linuxbox.cz> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="r5Pyd7+fXNt84Ff3" Cc: stable@kernel.org, netdev@vger.kernel.org To: linux-kernel mlist Return-path: Content-Disposition: inline In-Reply-To: <20111222151908.GA11020@pcnci.linuxbox.cz> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org --r5Pyd7+fXNt84Ff3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > after updating one of our servers to 3.0.12 kernel, it became painfully s= low (actually > it's almost unusable). >=20 > trying perf top, I see following: >=20 > 27465.00 - 59.8% : unregister_pernet_gen_subsys > 3144.00 - 6.8% : __start_notes > 1211.00 - 2.6% : swiotlb_sync_sg > 1155.00 - 2.5% : swiotlb_unmap_sg_attrs > 621.00 - 1.4% : pci_pm_init > 565.00 - 1.2% : swiotlb_map_sg_attrs > 503.00 - 1.1% : cgroup_attach_task crap, I was using too old perf binary - that might be reason why I wasn't a= ble to find any evidence of unregister_pernet_gen_subsys for 3.x kernels :) I switched to 3.0.13 now (and actual perf) and it seems better.. Should the problem reappear, I'll report it.. sorry for the fuzz.. n. >=20 > I wasn't too successfull trying to find something related, so I'd like to= ask, > which subsystem might be calling unregister_pernet_gen_subsys and why? > I guess this is certaingly a bug... Could somebody please have a look at = this? > I'll provide all debugging information I can if needed.. >=20 > thanks a lot in advance >=20 > with best regards >=20 > nik >=20 > --=20 > ------------------------------------- > Ing. Nikola CIPRICH > LinuxBox.cz, s.r.o. > 28. rijna 168, 709 01 Ostrava >=20 > tel.: +420 596 603 142 > fax: +420 596 621 273 > mobil: +420 777 093 799 > www.linuxbox.cz >=20 > mobil servis: +420 737 238 656 > email servis: servis@linuxbox.cz > ------------------------------------- --=20 ------------------------------------- Ing. Nikola CIPRICH LinuxBox.cz, s.r.o. 28. rijna 168, 709 01 Ostrava tel.: +420 596 603 142 fax: +420 596 621 273 mobil: +420 777 093 799 www.linuxbox.cz mobil servis: +420 737 238 656 email servis: servis@linuxbox.cz ------------------------------------- --r5Pyd7+fXNt84Ff3 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iEYEARECAAYFAk7zpq4ACgkQ3xdJJrLygV5nLQCgzNe8REKERQOqm5Ib1A/1h++j ccgAoJXmhf3bRgoVy6QCgCtGIMzBQq+2 =cpBN -----END PGP SIGNATURE----- --r5Pyd7+fXNt84Ff3--