From mboxrd@z Thu Jan  1 00:00:00 1970
From: Namhyung Kim <namhyung@gmail.com>
Subject: Re: Use of double pointer in linux kernel Hash list implementation
Date: Thu, 17 Jun 2010 12:32:25 +0900
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To: Balachandar <bala1486@gmail.com>
Cc: kernelnewbies@nl.linux.org, linux-c-programming@vger.kernel.org


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2010-06-16 (=EC=88=98), 22:50 -0400, Balachandar:
> Hi,
>   I am trying to understand Linux Kernel implementation of linked list
> and hash table. A link to the implementation is here. I understood the
> linked list implementation. But i am little confused of why double
> pointers is being used in hlist (**pprev). Link for hlist is here. I
> understand that hlist is used in implementation of hash table since
> head of the list requires only one pointer and it saves space. Why
> cant it be done using single pointer (just *prev like the linked
> list)? Please help me.
>=20
>=20
> Thanks,
> Bala


IMHO **pprev is only needed for fast deletion and/or insertion.


--=20
Regards,
Namhyung Kim


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