Messages in this thread | | | Date | Tue, 14 Dec 2004 13:58:25 -0800 (PST) | From | Christoph Lameter <> | Subject | Re: [PATCH 1/7] cpu-timers: high-resolution CPU clocks for POSIX clock_* syscalls |
| |
On Tue, 14 Dec 2004, Roland McGrath wrote:
> I believe Christoph may have been referring exclusively to the per-process > clocks, not the per-thread clocks. I'm not entirely sure since he used the > term "process" exclusively, but quoted my paragraph about the per-thread > clock access. Ulrich's reply is apropos to the individual thread clocks. > > It was about the per-process clocks that I raised the question. For those, > POSIX says it's implementation-defined what process can see the CPU clock > of another process. That means we can make it as restricted or as free as > we like, but we are obliged to document up front for the users what the > semantics are. That's why I would like to make sure we have thought a > little about the choices now, rather than someone coming along later and > deciding we really ought to impose security on it (which might be be > changing the story after developers reasonably coded to the > implementation-defined behavior we documented in the first place).
The threads are processes under Linux and thus may also be identified by a pid. You are right, this is a Linux centric view and this identificaition is not applicable to other systems. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |