Ralph, Can you point me to the small reproducer for the libevent bug that was fixed? I'm just curious.
Thanks, Josh On Fri, May 4, 2012 at 4:09 PM, Ralph Castain <r...@open-mpi.org> wrote: > FYI: 2.0.19-stable was released yesterday. I have a Mercurial repo all set to > go: > > https://bitbucket.org/rhc/ompi-libevent2019 > > Please check it out - timeout is now set for May 11th. > > Thanks > Ralph > > On May 1, 2012, at 8:38 AM, Ralph Castain wrote: > >> WHAT: Update libevent to 2.0.19 release >> >> WHEN: As soon as it is released, expected around May 11 >> >> WHY: The 2.0.19 release contains a critical fix to a bug I recently >> discovered in the libevent 2.0.x series >> >> >> Details: >> I discovered a bug in libevent over the last few days that causes it to >> unexpectedly "invert" event priorities. It is a slightly subtle bug, but we >> were able to provide a simple reproducer and so the libevent folks were able >> to quickly implement a fix. >> >> Stated simply, if you were in an event of a given priority and activated an >> event of higher priority, that new event would not get serviced if any event >> of the current priority were to become active prior to leaving the current >> event. In other words, libevent would service all active events of the >> current priority before even looking to see if a higher priority event was >> active. >> >> The patch adds the following logic to event_active: >> >>> IF <I am in an event> AND >>> IF <ev->base> EQ <current-base> AND >>> IF <pri> LT <current-pri> THEN >>> <rescan queues on next loop> >> >> >> Thus, a rescan only occurs if a higher priority event becomes active during >> an event of lower priority. Unfortunately, ORTE relies on this behavior to >> handle errors - without the change, an error reported in a message from a >> daemon (for example) cannot be serviced until ALL messages that arrive >> during the processing of the message have been handled. In the case of a >> large cluster that is receiving a long list of messages, this prevents the >> error from being handled for quite some time. >> >> > > > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel -- Joshua Hursey Postdoctoral Research Associate Oak Ridge National Laboratory http://users.nccs.gov/~jjhursey
