[Skiboot] [PATCH V3 5/6] Introduces get and put elog routine and reference count field in elog structure

Mukesh Ojha mukesh02 at linux.vnet.ibm.com
Mon Jul 11 15:43:26 AEST 2016

On Thursday 30 June 2016 02:50 PM, Stewart Smith wrote:
> Mukesh Ojha <mukesh02 at linux.vnet.ibm.com> writes:
>> Introduces a reference count variable in the errorlog structure, which is
>> to track the number of user of errorlog buffer.
>> get_elog and put_elog routine to increment/decrement the reference count variable.
>> errorlog buffer return to the pool on zero count of reference count.
>> The reason of introducing this patch, as in BMC systems, we use the same
>> errorlog buffer to send the log to both BMC, and to the host kernel. This
>> patch ensures that one does not free the buffer, while the other is
>> using it.
> Why not use lists? Have a list for error logs that need to be sent to
> FSP/BMC/whatever. That way you could queue up a few while the BMC
> reboots or something and send them across. Odds are you'll want to use
> the pool allocator in include/pool.h for that so that we don't have the
> possibility of running out of heap.
Currently , For the open power machines opal errorlogs are sent to the 
BMC only.
As, BMC has limitation of entries.

Our aim is via this patchset we can send the opal errorlog to the host 
as well apart
from sending it to the BMC. This also takes care of the case if BMC 
reboots, we can
get those errorlogs in host.

In case of FSP, we send the errorlog to host only if the opal fail to 
commit the errorlog
within a particular time. So, this also takes care of the case, if FSP 


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