Re: [RFC patch 00/20] Kernel tracing thread flag

From: Roland McGrath
Date: Sun May 10 2009 - 19:06:44 EST


I suspect you will hit troubles with some arch's not having a bit to spare.
(Even on x86, it probably hurts several bytes of cache wastage to have to
use longer immediates in some 'test' instructions.)

Another direction to go for this is overloading TIF_SYSCALL_TRACE, so we do
not need any arch changes. Before the end of the ptrace cleanup work that
Oleg is in the middle of, it should become simple to divorce ptrace's own
bookkeeping from TIF_SYSCALL_TRACE. At that point, we just need a little
bit of cooperation (in generic non-arch code) to overload that bit for
multiple simultaneous purposes.


Thanks,
Roland
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/