Date: Wed, 14 Dec 2005 19:52:03 -0500 From: Kris Kennaway <kris@obsecurity.org> To: Kevin Oberman <oberman@es.net> Cc: stable@freebsd.org, Kris Kennaway <kris@obsecurity.org> Subject: Re: Odd performance problems after upgrade from 4.11 to 6.0-Stable Message-ID: <20051215005203.GA89670@xor.obsecurity.org> In-Reply-To: <20051215004547.EAE465D07@ptavv.es.net> References: <20051215003403.GA89393@xor.obsecurity.org> <20051215004547.EAE465D07@ptavv.es.net>
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--45Z9DzgjV8m4Oswq Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Dec 14, 2005 at 04:45:47PM -0800, Kevin Oberman wrote: > > Date: Wed, 14 Dec 2005 19:34:04 -0500 > > From: Kris Kennaway <kris@obsecurity.org> > >=20 > > On Wed, Dec 14, 2005 at 04:26:18PM -0800, Kevin Oberman wrote: > >=20 > > > I am attaching a dmesg. I do have a few of drivers (uhci, pcm, psm, > > > atkbd0 and ichsmb) that are still marked as GIANT-LOCKED, but I'm not > > > using the USB very often. And I'm not using pcm or ichsmb during the > > > dump, either. I think everyone has the mouse and keyboard under GIANT, > > > but I can't really see those as a problem, either. > >=20 > > A bunch of things are sharing interrupts with USB..disable it and see > > if that helps. Also check vmstat -i to see if some device is > > storming. If not, turn on MUTEX_PROFILING(9) in your kernel and run > > the dump (or something faster that also exhibits the problem), then > > look for what is contending with Giant. >=20 > Yes, it may be time for MUTEX_PROFILING. I had already looked at > interrupts. My kernel is sans APIC so I didn't really think that > interrupts were a problems and I see: > interrupt total rate > irq0: clk 207037779 1000 > irq1: atkbd0 50208 0 > irq6: fdc0 9 0 > irq8: rtc 26498038 128 > irq10: pcm0 ichsmb0 2 0 > irq11: xl0 uhci0 18076067 87 > irq12: psm0 869500 4 > irq13: npx0 1 0 > irq14: ata0 10423468 50 > irq15: ata1 112 0 > Total 262955184 1270 >=20 > Clearly no storms and nothing looks obviously broken. USB and the > network card share an IRQ, but the USB is not connected to anything and > I would not think that it is generating many interrupts. The network > IS being used and I'm not seeing all that many interrupts on IRQ11. Whenever there is an interrupt on irq11 from the NIC, *both* drivers will wake up to process it. uhci0 will need to acquire Giant. If something else is also trying to acquire Giant (bufdaemon), then they will serialize, degrading performance. This may not be the cause since there are only a few interrupts, but MUTEX_PROFILING will tell you. Kris --45Z9DzgjV8m4Oswq Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQFDoL4yWry0BWjoQKURAuZFAKDUwuAu9BElsCzvxjV08ew9/a2flACff3eW WOdlC7m365q8eabbq1xSMnU= =ph/3 -----END PGP SIGNATURE----- --45Z9DzgjV8m4Oswq--
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