[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH net] xen-netback: add the scenario which now beyond the range time_after_eq().
On 2013-10-18 19:24, Wei Liu wrote: On Fri, Oct 18, 2013 at 09:40:33AM +0100, David Laight wrote:My understanding is this patch does not simply double the span, it is just stricter than the original one. Please check my previous comments, I paste it here.No, the code (on a 32-bit arch) just _can't_ handle jiffies differences beyond 2^32, no matter how cleverly you use the respective macros. All arithmetic there is done modulo 2^32.I haven't followed this discussion very closely but it might be possible to arrange that the 'incorrect lack of credit' only occurs for a few seconds every time 'jiffies' wraps - instead of half of the time. Then you'd have to be extremely unlucky to hit the timing window.As I understand it, this is the idea of this patch -- to narrow down the timing window. Jan, do you agree the idea or have better suggestion to me. Thanks, Jason Wei.David -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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