Messages in this thread | | | Date | Wed, 5 Jan 2011 10:43:05 -0500 | From | Jason Baron <> | Subject | [PATCH 0/2] jump label: 2.6.38 updates |
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Hi,
The first patch uses the storage space of the jump label key address as a pointer into the update table. In this way, we can find all the addresses that need to be updated without hashing.
The second patch introduces:
static __always_inline bool static_branch(struct jump_label_key *key);
instead of the old JUMP_LABEL(key, label) macro.
In this way, jump labels become really easy to use:
Define:
struct jump_label_key jump_key;
Can be used as:
if (static_branch(&jump_key)) do unlikely code
enable/disale via:
jump_label_enable(&jump_key); jump_label_disable(&jump_key);
that's it!
For perf, which also uses jump labels, I've left the reference counting out of the jump label layer, thus removing the 'jump_label_inc()' and 'jump_label_dec()' interface. Hopefully, this is a more palatable solution.
Thanks to H. Peter Anvin for suggesting the simpler 'static_branch()' function.
thanks,
-Jason
Jason Baron (2): jump label: make enable/disable o(1) jump label: introduce unlikely_switch()
arch/sparc/include/asm/jump_label.h | 25 ++++--- arch/x86/include/asm/jump_label.h | 22 ++++--- arch/x86/kernel/jump_label.c | 2 +- include/linux/dynamic_debug.h | 24 ++----- include/linux/jump_label.h | 66 ++++++++++-------- include/linux/jump_label_ref.h | 36 +++------- include/linux/perf_event.h | 28 ++++---- include/linux/tracepoint.h | 8 +-- kernel/jump_label.c | 129 +++++++++++++++++++++++++++-------- kernel/perf_event.c | 24 ++++-- kernel/tracepoint.c | 22 ++---- 11 files changed, 226 insertions(+), 160 deletions(-)
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