Messages in this thread | | | Date | Tue, 21 Aug 2012 10:38:39 +0400 | From | Michael Tokarev <> | Subject | Re: root=PARTUUID for MBR/NT disk signatures? |
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On 21.08.2012 08:47, Will Drewry wrote: [] > Functionally, I suspect this will work fine, but I am concerned that > it is a bad move from an efficiency perspective (not unfixable > though). Right now, the user-supplied value is converted from > string-uuid to packed-uuid. This is then memcmp'd across any and all > partitions - be it 2 or 200 - across all attached storage. If we move > to a pure string, then we end up needing to unpack every packed UUID > at disk scan time (or search, depending on impl) rather than just the > one user supplied value. > > Perhaps the cost is negligible on modern machines, but it seems like > the wrong place to put the cost (per entry rather than per search > value).
Amount of work needed to READ all the partition tables might be quite a bit larger than strcmp'ing it all. I think.
/mjt
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