Messages in this thread | | | Date | Thu, 3 Sep 1998 16:40:35 +0200 | From | Alexander Kjeldaas <> | Subject | Re: Differences between FreeBSD and Linux system call mechanism |
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On Thu, Sep 03, 1998 at 02:47:10PM +0100, Alan Cox wrote: > > > 1) Linux system calls are done using software interrupt 0x80 on ia32. > > Does this qualify as a "call-gate based kernel entry"? > > No. Call gates are a paticular intel mechanism for jumping between rings > (priviledge levels). You can see an example of this in the iBCS2 handlers > since iBCS uses call gates. An int based call is faster, and sysenter > is potentially faster still but sysenter is only on some later PII chips >
Doesn't this mean that it would be a good idea to let the kernel implement system calls by mapping a page into user-space containing the appropriate assembly instructions to most efficiently do the system calls?
astor
-- Alexander Kjeldaas, Guardian Networks AS, Trondheim, Norway http://www.guardian.no/
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