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| author | Peter Zijlstra <peterz@infradead.org> | 2023-01-12 20:44:04 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-01-13 11:48:18 +0100 |
| commit | 0e985e9d22864e29d5d2b3d909ad15134d7f6d46 (patch) | |
| tree | 710fbac5e48688b81dec48394c2007de459252ce /include/linux/compiler_types.h | |
| parent | 26388a7c353f7b1d3fd8a6df6452fa9773193155 (diff) | |
| download | linux-0e985e9d22864e29d5d2b3d909ad15134d7f6d46.tar.gz linux-0e985e9d22864e29d5d2b3d909ad15134d7f6d46.tar.bz2 linux-0e985e9d22864e29d5d2b3d909ad15134d7f6d46.zip | |
cpuidle: Add comments about noinstr/__cpuidle usage
Add a few words on noinstr / __cpuidle usage.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230112195542.397238052@infradead.org
Diffstat (limited to 'include/linux/compiler_types.h')
| -rw-r--r-- | include/linux/compiler_types.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index d7858901f035..dea5bf5bd09c 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -239,6 +239,16 @@ struct ftrace_likely_data { #define noinstr __noinstr_section(".noinstr.text") +/* + * The __cpuidle section is used twofold: + * + * 1) the original use -- identifying if a CPU is 'stuck' in idle state based + * on it's instruction pointer. See cpu_in_idle(). + * + * 2) supressing instrumentation around where cpuidle disables RCU; where the + * function isn't strictly required for #1, this is interchangeable with + * noinstr. + */ #define __cpuidle __noinstr_section(".cpuidle.text") #endif /* __KERNEL__ */ |