Commit Graph

5 Commits

Author SHA1 Message Date
Michel Lespinasse 4c199a93a2 rbtree: empty nodes have no color
Empty nodes have no color.  We can make use of this property to simplify
the code emitted by the RB_EMPTY_NODE and RB_CLEAR_NODE macros.  Also,
we can get rid of the rb_init_node function which had been introduced by
commit 88d19cf379 ("timers: Add rb_init_node() to allow for stack
allocated rb nodes") to avoid some issue with the empty node's color not
being initialized.

I'm not sure what the RB_EMPTY_NODE checks in rb_prev() / rb_next() are
doing there, though.  axboe introduced them in commit 10fd48f237
("rbtree: fixed reversed RB_EMPTY_NODE and rb_next/prev").  The way I
see it, the 'empty node' abstraction is only used by rbtree users to
flag nodes that they haven't inserted in any rbtree, so asking the
predecessor or successor of such nodes doesn't make any sense.

One final rb_init_node() caller was recently added in sysctl code to
implement faster sysctl name lookups.  This code doesn't make use of
RB_EMPTY_NODE at all, and from what I could see it only called
rb_init_node() under the mistaken assumption that such initialization was
required before node insertion.

[sfr@canb.auug.org.au: fix net/ceph/osd_client.c build]
Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:32 +09:00
John Stultz 88d19cf379 timers: Add rb_init_node() to allow for stack allocated rb nodes
In cases where a timerqueue_node or some structure that utilizes
a timerqueue_node is allocated on the stack, gcc would give warnings
caused by the timerqueue_init()'s calling RB_CLEAR_NODE, which
self-references the nodes uninitialized data.

The solution is to create an rb_init_node() function that zeros
the rb_node structure out and then calls RB_CLEAR_NODE(), and
then call the new init function from timerqueue_init().

CC: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2011-04-26 14:01:42 -07:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Thomas Gleixner 45f74264e1 timerqueue: Make timerqueue_getnext() static inline
No point in calling a function just to dereference a pointer.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
2010-12-11 12:34:34 +01:00
John Stultz 1f5a24794a timers: Rename timerlist infrastructure to timerqueue
Thomas pointed out a namespace collision between the new timerlist
infrastructure I introduced and the existing timer_list.c

So to avoid confusion, I've renamed the timerlist infrastructure
to timerqueue.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2010-12-10 11:52:17 -08:00