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| author | Jens Axboe <axboe@kernel.dk> | 2022-09-22 10:03:51 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-09-22 10:03:51 -0600 |
| commit | 0574e8c3b2b47e1e2564c2f50ea0b6f2629f2e48 (patch) | |
| tree | ff3fa05199b77eafb40944ad8128b7042ab0bd44 | |
| parent | d14687025c0c61d047e4252036d1b024d62cb0a6 (diff) | |
| download | fio-master.tar.gz fio-master.tar.bz2 | |
This prevents counter value speculation, which will otherwise cause
issues with the CPU clock.
Link: https://github.com/axboe/fio/issues/1472
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | arch/arch-aarch64.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arch-aarch64.h b/arch/arch-aarch64.h index 951d1718..919e5796 100644 --- a/arch/arch-aarch64.h +++ b/arch/arch-aarch64.h @@ -27,10 +27,13 @@ static inline int arch_ffz(unsigned long bitmask) #define ARCH_HAVE_FFZ +#define isb() asm volatile("isb" : : : "memory") + static inline unsigned long long get_cpu_clock(void) { unsigned long val; + isb(); asm volatile("mrs %0, cntvct_el0" : "=r" (val)); return val; } |