We are engaged in an argument as to whether or not Solaris on Sparcs can
really support "hard" real-time. We want to architect a system composed
of background off-the-shelf processes (e.g. RDBMSs, HTML browsers)
overlaid with selected data acquisition processes which have hard
requirements, the worst of which is a moderate 20 ms.
As a note, by "hard" real-time, I mean processes which have dispatch
deadlines which must be met. In our case, data acquisition hardware must
be responded to or it will become discombobulated. This also implies that
priority inversion problems have been worked such that the higher priority
processes don't get hung up by lower ones due to shared semaphores and the
Our researches so far (newgroup searches, SunSoft documentation searches,
urban legends) indicate that Solaris 2.5 (we have 2.5.1) does support hard
real-time, and also supports fully (??) the POSIX threads and real-time
Can anyone comment on these seemingly positive results? Does anyone have
any benchmarks concerning interrupt service / dispatch latency for
real-time priorities on Sparc 20 or Ultra platforms? Any pointers to
relevant docs available?
Any comments, positive or negative would be appreciated. We're going to
setup and run benchmarks on a set of networked Ultras, but have no
guarantee we'll find all the dispatches bugs.