Linus Torvalds writes: (Summary) wrote:
It's a traditional trick to get the upper 32 bits.
So it basically splits the (possibly 64-bit) pointer into the lower 32 bits and the upper 32 bits for a hash such as "jhash()" that takes data that is "unsigned int".
data that is "unsigned int".
(NOTE! Using jhash here is not acceptable, since it's not cryptographically safe, but think of it as an example of a hash that takes 32-bit input).
takes 32-bit input).
Doing ">>
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I did not understand the code (specifically why the right shift of 16 twice?) It's a traditional trick to get the upper 32 bits.It's a traditional trick to get the upper 32 bits.
So it basically splits the (possibly 64-bit) pointer into the lower 32 bits and the upper 32 bits for a hash such as "jhash()" that takes data that is "unsigned int".
data that is "unsigned int".
(NOTE! Using jhash here is not acceptable, since it's not cryptographically safe, but think of it as an example of a hash that takes 32-bit input).
takes 32-bit input).
Doing ">>