Adar Dembo has posted comments on this change.

Change subject: random: add a Rand64() variant which uses all bits
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Patch Set 3: Code-Review+2

(1 comment)

http://gerrit.cloudera.org:8080/#/c/5474/3/src/kudu/util/random.h
File src/kudu/util/random.h:

Line 93:   // This is 1.5x slower than 'Next64()' above, but randomizes all 
bits.
Do we care so much about the speed of Next64() that we shouldn't just extend it 
to cover all 64 bits? The number of non-test instances of Next64() is very low. 
The most prominent one is the block manager, where I'd expect the cost of the 
RNG to be dwarfed by the system calls opening/creating files.

In other cases, we're going through ThreadSafeRandom so we are already okay 
with the possible slowdown of a spin-wait.


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Gerrit-MessageType: comment
Gerrit-Change-Id: I6064ae18532bc32f24086e232200f1f0966d6b2a
Gerrit-PatchSet: 3
Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-Owner: Todd Lipcon <[email protected]>
Gerrit-Reviewer: Adar Dembo <[email protected]>
Gerrit-Reviewer: Kudu Jenkins
Gerrit-HasComments: Yes

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