Move typically true check for static syscall out of syscall_thread_enter/exit functions into an inline.
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Authored by mjg on Oct 25 2014, 2:17 AM.

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Move typically true check for static syscall out of syscall_thread_enter/exit functions into an inline.

Prefix original functions with an _.

According to ministat this gives roughly a 4% speedup when calling getuid()
in a loop (syscall_timing benchmark found in tools/tools).

I was considering getting rid of 'td' argument as well as it is unused.

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rS FreeBSD src repository - subversion

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mjg updated this revision to Diff 2112.Oct 25 2014, 2:17 AM

mjg retitled this revision from to Move typically true check for static syscall out of syscall_thread_enter/exit functions into an inline..

mjg updated this object.

mjg edited the test plan for this revision. (Show Details)

mjg updated this object.Oct 25 2014, 2:20 AM

mjg added a reviewer: jhb.Oct 26 2014, 6:32 PM

the idea is half-crap - this code still remains in the hot path, even though it can be eliminated. this can be accomplished by providing a extra system call table and a proxy handler installed in the regular one. the proxy handler will inspect regs and whatnot and will get the syscall number + args from there. it can then proceed to do the crappery to safely call the syscall.