One of the early challenges for systems like the SPARCcenter2000 was that Solaris only supported 48 TELNET users by default. But as this limit was removed, Solaris would die from heavy lock contention triggered by in.telnetd in poll(). Whilst on my first SE Job Rotation, it seemed to me that the obvious solution was to recode the TELNET service using a STREAMS module. At the time I didn’t have the kernel skills to do this, but I knew someone who did. However, they needed a business case to do the work. I implemented a poll()-free TELNET service using the newly available user-level threads library (i.e. one process handling hundred of TELNET sessions). My data provided the business case, and in.telnetd was given its STREAMS implementation.

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