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 19:39:30 +0100 |
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On Wed, 2010-11-24 at 13:24 -0500, Jason Baron wrote: > By storing the state of the jump label with each key, we make > sure that when modules are added, they are updated to the correct > state. For example, if the kmalloc tracepoint is enabled and > a module is added which has kmalloc, we make sure that the tracepoint > is properly enabled on module load. > > Also, if jump_label_enable(key), is called but the key has not yet > been added to the hashtable of jump label keys, add 'key' to the table. > In this way, if key value has its state updated, but we have not > yet encountered a JUMP_LABEL() definition for it (if its located in > a module), we ensure that the jump label is set to the correct > state when it finally is encountered. > > When modules are unloaded, we traverse the jump label hashtable, > and remove any entries that have a key value that is contained > by that module's text section. In this way key values are properly > unregistered, and can be re-used.
So why again are we adding all this complexity? Does this really need to be optimized in the face of how expensive text pokes are?
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