Hello. I have been writing my own microkernel using ideas from L4 and other kernels.
I am curious as to whether or not there would be an appreciable performance increase if the L4 system calls were split up into multiple calls. For example, the IPC call is be used to send messages, recieve messages, and to do RPC. Wouldn't it be faster if each of those were separate system calls (since it would require less if-then logic and bit manipulation)? Is there any reason not to do this?
In addition, I am seeking well-commented, easy to understand scheduling algorithms or detailed descriptions of them. Right now I am using a nice, simple round-robin scheduler that doesn't even take priorities into account. It is very efficient, however. 8-)
Also, does L4 have any support for semaphores? I was unable to find anything in the documentation.
Thanks Geoff
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In addition, I am seeking well-commented, easy easy to understand scheduling algorithms or detailed descriptions of them....
Fine explanations can be found at W. Stallings Operating Systems, Tanenbaum Operating Systems, Gary Nutt Operating Systems. Scan the OSDI / SOSP papers for newer stuff (check the authors site if access is restricted).
-----Original Message----- From: owner-l4-hackers@os.inf.tu-dresden.de [mailto:owner-l4-hackers@os.inf.tu-dresden.de] On Behalf Of Geoff Humphreys Sent: Mittwoch, 20. Oktober 1999 13:41 To: l4-hackers@os.inf.tu-dresden.de Subject: A few questions
Hello. I have been writing my own microkernel using ideas from L4 and other kernels.
I am curious as to whether or not there would be an appreciable performance increase if the L4 system calls were split up into multiple calls. For example, the IPC call is be used to send messages, recieve messages, and to do RPC. Wouldn't it be faster if each of those were separate system calls (since it would require less if-then logic and bit manipulation)? Is there any reason not to do this?
In addition, I am seeking well-commented, easy to understand scheduling algorithms or detailed descriptions of them. Right now I am using a nice, simple round-robin scheduler that doesn't even take priorities into account. It is very efficient, however. 8-)
Also, does L4 have any support for semaphores? I was unable to find anything in the documentation.
Thanks Geoff
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l4-hackers@os.inf.tu-dresden.de