forked from luck/tmp_suning_uos_patched
f74445b6dd
While documentation suggests atomic_inc_not_zero_hint() will perform better than atomic_inc_not_zero(), this is unlikely to be the case. No architectures implement atomic_inc_not_zero_hint() directly, and thus it either falls back to atomic_inc_not_zero(), or a loop using atomic_cmpxchg(). Whenever the hint does not match the value in memory, the repeated use of atomic_cmpxchg() will be more expensive than the read that atomic_inc_not_zero_hint() attempts to avoid. For architectures with LL/SC atomics, a read cannot be avoided, and it would always be better to use atomic_inc_not_zero() directly. For other architectures, their own atomic_inc_not_zero() is likely to be more optimal than an atomic_cmpxchg() loop regardless. Generally, atomic_inc_not_zero_hint() is liable to perform worse than atomic_inc_not_zero(). Further, atomic_inc_not_zero_hint() only exists for atomic_t, and not atomic64_t or atomic_long_t, and there is only one user in the kernel tree. Given all this, let's remove atomic_inc_not_zero_hint(), and migrate the existing user over to atomic_inc_not_zero(). There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-4-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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| .. | ||
| addr.c | ||
| addr.h | ||
| atm_misc.c | ||
| atm_sysfs.c | ||
| br2684.c | ||
| clip.c | ||
| common.c | ||
| common.h | ||
| ioctl.c | ||
| Kconfig | ||
| lec_arpc.h | ||
| lec.c | ||
| lec.h | ||
| Makefile | ||
| mpc.c | ||
| mpc.h | ||
| mpoa_caches.c | ||
| mpoa_caches.h | ||
| mpoa_proc.c | ||
| pppoatm.c | ||
| proc.c | ||
| protocols.h | ||
| pvc.c | ||
| raw.c | ||
| resources.c | ||
| resources.h | ||
| signaling.c | ||
| signaling.h | ||
| svc.c | ||