Messages in this thread | | | Date | Wed, 28 Oct 2009 10:09:28 -0700 | From | Mike Travis <> | Subject | Re: [PATCH] x86, mce: disable MCE if cpu has no MCE banks |
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Hidetoshi Seto wrote: > Andi Kleen wrote: >> Hidetoshi Seto wrote: >>> Without disabling, what can we do on MCE with no bank? >> Nothing, but is it really worth adding a special case? > > If question were: > - is it really worth to support this special environment, > "MCE-capable but no MCE banks" ? > then I'd like to say no. > > So I suggested to disable MCE on this uncertain environment. > Or we will end up adding more codes for special cases... > >>> I found that do_machine_check() does nothing if banks==0 ... it is better >>> to let system to panic with "Machine check from unknown source"? >> IMHO yes. In this case the system must be very confused and panic is the >> best you can do. Otherwise it won't do anything interesting anyways. > > Agreed, but this is also a special case. > Not depending on the real number of banks, confused system could fail to > get the value from memory... Humm, in theory MCE handler must be > implemented carefully, but I bet the confused value will not be always 0, > ... is it worth to do? > >>>>> Hum, I suppose the line for CPU 0 was slightly different from others, >>>>> because SHD means "this bank is shared bank and controlled by other". >>>>> Maybe: >>>>> CPU 0 MCA banks CMCI:0 CMCI:1 CMCI:2 CMCI:3 CMCI:5 ... CMCI:21 >>>>> >>>>> But I agree that we could some work for this messages... >>>>> Is it better to change the message level to debug from info? >>>> Can be made INFO yes, but I would prefer not removing them >>>> from the dmesg for now. >>>> >>>> Perhaps they could be also compressed a bit like SRAT. >>> Like SRAT? I could not catch the meaning ... For example? >> See the recent patches from David Rientjes in the same original thread. > > I found it, thanks. > > So I suppose your idea is like: > CPU 0 MCA banks CMCI:{0-3,5-9,12-21} POLL:{4,10,11} > CPU 1 MCA banks SHD:{0,1,6-9,12-21} CMCI:{2,3,5} POLL:{4,10,11} > right? > > IMHO the format I suggested is better to read, as far as banks is > not so big number. > CPU 0 MCA banks map : CCCC PCCC CCPP CCCC CCCC CC > CPU 1 MCA banks map : ssCC PCss ssPP ssss ssss ss > > > Thanks, > H.Seto
The problem comes up when you have a whole bunch of cpus, and the lines become redundant. Can you compress the lines so that cpus with the same given mappings are printed on one line?
Thanks, Mike
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