Messages in this thread | | | From | "Michael S. Zick" <> | Subject | Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic | Date | Sun, 24 May 2009 07:27:27 -0500 |
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On Sat May 23 2009, H. Peter Anvin wrote: > Hi Harald, > > It looks like there might be a problem with the C7-M ... Michael reports > that if he sets LOCK_PREFIX to "lock;" it works, but that shouldn't be > necessary for a uniprocessor. > > I'm wondering if we have to revive the OOSTORE hack, or some other > workaround. It is of course hard for me to track this down since (a) I > don't have access to the CPU documentation, and (b) I work for Intel > now, which limits the amount of time I can realistically spend on this. >
@hpa - I still like your suggestion that it is only one (or a few) uses of atomic ops that is incorrect and in general atomic ops should compile away on uni-processor.
Let me translate the findings (see further in the included post) - The C7-M/CN896 (no tech manual released for CN896 yet) and the C7-M/CX700 (tech manual released since drivers written)
*) I never tested -09143lk on the C7-M/CN896 because -09143 did not fail all day (a record for 2.6.30 at the moment).
*) The difference on the C7-M/CX700 between the -09143 and -09143lk I consider significant.
***) But, keep in mind, just because the system chip set is different, there are other unknowns - - We can *not* say at the moment that both machines where using the same execution paths - even though the binaries where identical.
Also, there where probably different external modules loaded in the two runs - not many, mostly things are built-in.
The truly significant point on the C7-M/CX700 running -09143lk was that when the echi-hcd driver got hung in its failure loop, generating a flood of messages - it did not take down or lock the kernel.
I consider this "forward progress" - it should be possible to build-in the lock-dep checkers and get something in the message buffer - rather than just have the machine halt. Its hard to debug a halted machine with only a glowing power-on light for feed-back. ;)
Mike
> -hpa > > [Cc: Alan, who I believed developed the OOSTORE hack back when.] > > > Michael S. Zick wrote: > > On Fri May 22 2009, H. Peter Anvin wrote: > >> Michael S. Zick wrote: > >>> Same integrated motherboard. > >> Which means same CPU, same BIOS, same motherboard (none of which you're > >> telling us.) > >> > >> cpuinfo and dmidecode would be informative. > >> > > > > The -09143lk files are posted. > > > > Download location: > > http://hp-umpc.com/ce1200v > > > > Details so far today: > > http://forum.netbookuser.com/viewtopic.php?pid=6968#p6968 > > > > Summary: > > HP-2133 (C7-M/CN896) - 09143 - No results - Still up 3 1/2 hours. > > Cloudbook (C7-M/CX700) - 09143 - 45 minutes. > > Cloudbook (C7-M/CX700) - 09143lk - No results - Still up 1 1/2 hours. > > > > OK - time to look for the missing "memory" in the clobber lists. ;) > > >
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