Messages in this thread | | | From | David Howells <> | Subject | Re: [RFC patch 08/18] cnt32_to_63 should use smp_rmb() | Date | Fri, 07 Nov 2008 17:04:57 +0000 |
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Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
> First off, using this macro with get_cycles() is simply buggy, because the > macro expects _perfect_ order of timestamps, no skew whatsoever, or > otherwise time could jump.
Erm... Why can't I pass it get_cycles()? Are you saying that sched_clock() in MN10300 is wrong for it's use of get_cycles() with cnt32_to_63()?
> __x.lo = readl(cnt_lo); /* mmio read */
readl() might insert an extra barrier instruction. Not only that, io_addr must be unsigned long.
David
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