Messages in this thread | | | Subject | Re: [PATCH 1/3] jump label: add enabled/disabled state to jump label key entries | From | Peter Zijlstra <> | Date | Wed, 24 Nov 2010 16:21:52 +0100 |
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On Wed, 2010-11-24 at 10:15 -0500, Steven Rostedt wrote: > On Wed, 2010-11-24 at 09:54 -0500, Jason Baron wrote: > > On Wed, Nov 24, 2010 at 09:20:09AM +0100, Peter Zijlstra wrote: > > > On Tue, 2010-11-23 at 16:27 -0500, Jason Baron wrote: > > > > struct hlist_head modules; > > > > unsigned long key; > > > > + u32 nr_entries : 31, > > > > + enabled : 1; > > > > }; > > > > > > I still don't see why you do this, why not simply mandate that the key > > > is of type atomic_t* and use *key as enabled state? > > > > > > > Because I want to use *key as a pointer directly to 'struct jump_label_entry'. > > In this way jump_label_enable(), jump_label_disable(), become O(1) operations. > > That way we don't need any hashing. > > I'm curious, how are you going to get the keys to point to the jump > label structures?
What jump label structure, we've got the section with:
{key-address, text-address}
tuples, keep that sorted and binary search it,. voila!
You don't need extra data, but since we have to have some data to have a key-address, use that storage for a simple refcount.
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