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| author |   Peter Zijlstra <peterz@infradead.org> | 2020-08-18 15:57:48 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2020-09-01 09:58:05 +0200 |
| commit | 452cddbff74b6a15b9354505671011700fe03710 (patch) | |
| tree | 75bd4702221b4ca983ef387cfd33f49262e050f0 /kernel/static_call.c | |
| parent | x86/alternatives: Teach text_poke_bp() to emulate RET (diff) | |
| download | linux-dev-452cddbff74b6a15b9354505671011700fe03710.tar.xz linux-dev-452cddbff74b6a15b9354505671011700fe03710.zip | |
static_call: Add static_call_cond()
Extend the static_call infrastructure to optimize the following common
pattern:
if (func_ptr)
func_ptr(args...)
For the trampoline (which is in effect a tail-call), we patch the
JMP.d32 into a RET, which then directly consumes the trampoline call.
For the in-line sites we replace the CALL with a NOP5.
NOTE: this is 'obviously' limited to functions with a 'void' return type.
NOTE: DEFINE_STATIC_COND_CALL() only requires a typename, as opposed
to a full function.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135805.042977182@infradead.org
Diffstat (limited to 'kernel/static_call.c')
0 files changed, 0 insertions, 0 deletions