Re: [RFC][PATCH] linux-2.6.2-rc2_vsyscall-gtod_B1.patch

[Ulrich Drepper <drepper _at_ xxxxxxxxxx>]

Ingo Molnar wrote:

> but i'm a bit worried about the apparent fact that adding 200 more
> symbols (and making the vDSO a real DSO in essence) to abstract the
> kernel syscalls is apparently unacceptable performance-wise. If this is
> true then the whole dynamic linking architecture is much slower than it
> should be, isnt it?

If the syscall entry code in the vdso takes care of the multiplexing we
do not have to add any symbols to the vdso's symbol table.  There are no
additional costs associated with adding more optimized syscalls other
than the multiplexer and that cost would be constant if a jump table is
used.

For now, the simple single cmpl is sufficient.

-- 
 Ulrich Drepper  Red Hat, Inc.  444 Castro St  Mountain View, CA 
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