Messages in this thread | | | Date | Tue, 23 Sep 2003 03:51:18 -0700 | From | "David S. Miller" <> | Subject | Re: NS83820 2.6.0-test5 driver seems unstable on IA64 |
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On Tue, 23 Sep 2003 20:40:05 +1000 Peter Chubb <peter@chubb.wattle.id.au> wrote:
> How expensive is it to take the trap and do a fix up, compared to > making an aligned copy? As it involves raising and handling a fault > disassembling the instruction that caused the fault, etc., I'd be > surprised if it's much less than 1000 cycles, even without the printk, > although I haven't measured it yet, and can't find enough info in the > architecture manuals to know what it is.
A cache miss can cause 100 or so cycles. :)
And unlike the fixup trap, the printk wakes up a process and causes disk activity as syslogd writes to the kernel message log file. - 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/
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