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From: Balachandar <bala1486@gmail.com>
To: kernelnewbies@nl.linux.org, linux-c-programming@vger.kernel.org
Subject: Use of double pointer in linux kernel Hash list implementation
Date: Wed, 16 Jun 2010 22:50:17 -0400	[thread overview]
Message-ID: <AANLkTilGln3yZRl1muugML4Qg_1rcTXTf3UeAIzLTOJT@mail.gmail.com> (raw)

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Hi,
  I am trying to understand Linux Kernel implementation of linked list and
hash table. A link to the implementation is
here<http://lxr.linux.no/linux+v2.6.34/include/linux/list.h>.
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<http://lxr.linux.no/linux+v2.6.34/include/linux/list.h#L554>.
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.

Thanks,
Bala

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             reply	other threads:[~2010-06-17  2:50 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-17  2:50 Balachandar [this message]
2010-06-17  3:32 ` Use of double pointer in linux kernel Hash list implementation Namhyung Kim
2010-06-17 14:34   ` Balachandar
2010-06-18  2:10     ` Namhyung Kim

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