Mark:
As a ex VMer when source code was shipped and also CICS when it was shipped. I know. I wasn't suggesting IBM code the Operating System in C. But asking because I have seen a ton of people in various publications claiming that you can do it with exits, like RACF. But as many things on the ‘net’, vaporware, few examples, fewer still that even work. I was exploring the possibility and thanks to Walt, I will not at this time for sure. Regards, Scott From: Mark Post Sent: Tuesday, April 29, 2014 7:05 PM To: IBM Mainframe Discussion List >>> On 4/29/2014 at 11:13 AM, Scott Ford <[email protected]> wrote: > Its surprising that IBM hasn't thought about using C in exits , like RACF or > other components. > > Considering Linux has been writing their Kernel in it for a few years. Not > bashing IBM, curious why they haven't embraced C in the systems arena. I see > it in some of the system type tools. Linux was initially written in C for whatever reason (most likely ease of coding and availability of a compiler), initially. As time went on, it stayed that way for relatively easy portability to other architectures. What having an entire operating system written in C does _not_ do, however, it wring the last bit of performance out of a particular hardware platform. It's one of the reasons why z/OS and z/VM were able to perform so well on systems like the 9672 or z800/z900, but Linux performance pretty much stank. From my perspective, it was Linux on System z that really pointed out how slow IBM mainframes were in raw CPU power (about 200MHz) compared to other architectures such as Power and Intel/AMD. Over time that situation has changed radically, of course, and now System z has the fastest CPU cycle times in the industry. But I doubt that would have happened as quickly as it did, if it weren't for IBM's desire to continue to sell hardware to run Linux on System z. And, if you look closely, sections of code in the kernel that are considered critical to overall system performance _are_ written in assembler for every architecture. I would say that given the fact that IBM isn't interested in porting z/OS (including RACF and the like) to other hardware platforms, they'd be insane to start coding large chunks of it in C. Mark Post ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
