Messages in this thread |  | | | Date | Wed, 02 Dec 2009 16:10:44 -0800 | | From | "H. Peter Anvin" <> | | Subject | Re: [PATCH 09/11] pps: low level IRQ timestamps recording. |
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On 12/02/2009 09:18 AM, Rodolfo Giometti wrote: > Add low level IRQ timestamps recording for x86 (32 and 64 bits) > platforms and enable UART clients in order to use it. > > This improves PPS precision. :)
It also invokes getnstimeofday on every single interrupt, including ones which have absolutely nothing to do with the PPS, and are potentially high volume. getnstimeofday can be a fairly expensive operation, especially if the best available clock is away from the CPU, or it requires extensive arithmetic in order to normalize the clock value...
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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