Subject: Re: [PATCH net-next 1/3] lib: Resizable, Scalable, Concurrent Hash Table

From: Nikolay Aleksandrov <[email-masked]>
Date: Sat, 02 Aug 2014 12:32:41 +0200

On 08/02/2014 11:47 AM, Thomas Graf wrote:
> Generic implementation of a resizable, scalable, concurrent hash table
> based on [0]. The implementation supports both, fixed size keys specified
> via an offset and length, or arbitrary keys via own hash and compare
> functions.
> 
> Lookups are lockless and protected as RCU read side critical sections.
> Automatic growing/shrinking based on user configurable watermarks is
> available while allowing concurrent lookups to take place.
> 
> Objects to be hashed must include a struct rhash_head. The reason for not
> using the existing struct hlist_head is that the expansion and shrinking
> will have two buckets point to a single entry which would lead in obscure
> reverse chaining behaviour.
> 
> Code includes a boot selftest if CONFIG_TEST_RHASHTABLE is defined.
> 
> [0] https://www.usenix.org/legacy/event/atc11/tech/final_files/Triplett.pdf
> 
> Signed-off-by: Thomas Graf <tgraf-G/[email-masked]>
> ---
>  include/linux/rhashtable.h | 213 ++++++++++++
>  lib/Kconfig.debug          |   8 +
>  lib/Makefile               |   2 +-
>  lib/rhashtable.c           | 797 +++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 1019 insertions(+), 1 deletion(-)
>  create mode 100644 include/linux/rhashtable.h
>  create mode 100644 lib/rhashtable.c
> 

Reviewed-by: Nikolay Aleksandrov <[email-masked]>