Date: Fri, 15 Aug 2003 17:34:58 +0200 From: Thomas Moestl <t.moestl@tu-bs.de> To: harti@freebsd.org Cc: sparc64@freebsd.org Subject: Re: Sparc slowdown - problem identified... Message-ID: <20030815153458.GC701@crow.dom2ip.de> In-Reply-To: <20030815165603.R92087@beagle.fokus.fraunhofer.de> References: <20030815121010.I97608@beagle.fokus.fraunhofer.de> <20030815135034.GA701@crow.dom2ip.de> <20030815165603.R92087@beagle.fokus.fraunhofer.de>
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On Fri, 2003/08/15 at 16:58:44 +0200, Harti Brandt wrote: > On Fri, 15 Aug 2003, Thomas Moestl wrote: > > TM>On Fri, 2003/08/15 at 12:20:39 +0200, Harti Brandt wrote: > TM>> > TM>> Hi all, > TM>> > TM>> it seems I have identified which commit causes the slow down on some > TM>> sparcs. The kernel from just before that commit works just fine, the > TM>> kernel from just after it is 3x slower on my Ultra-10 (as was also > TM>> reported by others). I have no idea why that happens. The only difference > TM>> in the time -l report is user and system time going up by a factor of > TM>> three and the involuntary context switches doubling. > TM> > TM>It seems that deferred errors (and thus the data access errors > TM>generated due to PCI bus timeouts from non-existant devices) will > TM>disable the instruction and data cache by resetting the corresponding > TM>enable bits in the LSU control register, and the current code fails to > TM>reenable them (which also requires a cache flush). A simple workaround > TM>for now is to avoid triggering these errors, so enabling OFW_NEWPCI > TM>should help. > > I can confirm that it helps. I assume that OFW_NEWPCI is currently there > to allow testing and one day to throw the switch and remove the old stuff? Yes. > Wouldn't it help to make it the default? Otherwise the testing will be > rather limited. I haven't made it the default because it can require configuration changes because of the different enumeration, as detailed in the warning notice in GENERIC and NOTES. I had hoped that making it an option would allow people could gradually change over their installations, so that the transition would be more painless. I guess I should make it the default soon. - Thomas -- Thomas Moestl <t.moestl@tu-bs.de> http://www.tu-bs.de/~y0015675/ <tmm@FreeBSD.org> http://people.FreeBSD.org/~tmm/ PGP fingerprint: 1C97 A604 2BD0 E492 51D0 9C0F 1FE6 4F1D 419C 776C
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