Switch out the conditional load interfaces used by rqspinlock to atomic_cond_read_acquire_timeout(), and smp_cond_read_acquire_timeout(). Both these handle the timeout and amortize as needed, so use check_timeout() directly. Also, when using spin-wait implementations, redefine SMP_TIMEOUT_POLL_COUNT to be 16k to be similar to the spin-count used in RES_CHECK_TIMEOUT(). Cc: Kumar Kartikeya Dwivedi Cc: Alexei Starovoitov Signed-off-by: Ankur Arora --- kernel/bpf/rqspinlock.c | 31 ++++++++++++++----------------- 1 file changed, 14 insertions(+), 17 deletions(-) diff --git a/kernel/bpf/rqspinlock.c b/kernel/bpf/rqspinlock.c index a00561b1d3e5..f35f078a158d 100644 --- a/kernel/bpf/rqspinlock.c +++ b/kernel/bpf/rqspinlock.c @@ -241,20 +241,14 @@ static noinline int check_timeout(rqspinlock_t *lock, u32 mask, } /* - * Do not amortize with spins when res_smp_cond_load_acquire is defined, - * as the macro does internal amortization for us. + * Amortize timeout check for busy-wait loops. */ -#ifndef res_smp_cond_load_acquire #define RES_CHECK_TIMEOUT(ts, ret, mask) \ ({ \ if (!(ts).spin++) \ (ret) = check_timeout((lock), (mask), &(ts)); \ (ret); \ }) -#else -#define RES_CHECK_TIMEOUT(ts, ret, mask) \ - ({ (ret) = check_timeout((lock), (mask), &(ts)); }) -#endif /* * Initialize the 'spin' member. @@ -268,6 +262,16 @@ static noinline int check_timeout(rqspinlock_t *lock, u32 mask, */ #define RES_RESET_TIMEOUT(ts, _duration) ({ (ts).timeout_end = 0; (ts).duration = _duration; }) +/* + * Limit how often check_timeout() is invoked while spin-waiting in + * smp_cond_load_acquire_timeout() or atomic_cond_read_acquire_timeout(). + * (ARM64, typically uses a waited implementation so we exclude that.) + */ +#ifndef CONFIG_ARM64 +#undef SMP_TIMEOUT_POLL_COUNT +#define SMP_TIMEOUT_POLL_COUNT (16*1024) +#endif + /* * Provide a test-and-set fallback for cases when queued spin lock support is * absent from the architecture. @@ -313,12 +316,6 @@ EXPORT_SYMBOL_GPL(resilient_tas_spin_lock); */ static DEFINE_PER_CPU_ALIGNED(struct qnode, rqnodes[_Q_MAX_NODES]); -#ifndef res_smp_cond_load_acquire -#define res_smp_cond_load_acquire(v, c) smp_cond_load_acquire(v, c) -#endif - -#define res_atomic_cond_read_acquire(v, c) res_smp_cond_load_acquire(&(v)->counter, (c)) - /** * resilient_queued_spin_lock_slowpath - acquire the queued spinlock * @lock: Pointer to queued spinlock structure @@ -418,7 +415,8 @@ int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val) */ if (val & _Q_LOCKED_MASK) { RES_RESET_TIMEOUT(ts, RES_DEF_TIMEOUT); - res_smp_cond_load_acquire(&lock->locked, !VAL || RES_CHECK_TIMEOUT(ts, ret, _Q_LOCKED_MASK)); + smp_cond_load_acquire_timeout(&lock->locked, !VAL, + (ret = check_timeout(lock, _Q_LOCKED_MASK, &ts))); } if (ret) { @@ -572,9 +570,8 @@ int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val) * us. */ RES_RESET_TIMEOUT(ts, RES_DEF_TIMEOUT * 2); - val = res_atomic_cond_read_acquire(&lock->val, !(VAL & _Q_LOCKED_PENDING_MASK) || - RES_CHECK_TIMEOUT(ts, ret, _Q_LOCKED_PENDING_MASK)); - + val = atomic_cond_read_acquire_timeout(&lock->val, !(VAL & _Q_LOCKED_PENDING_MASK), + (ret = check_timeout(lock, _Q_LOCKED_PENDING_MASK, &ts))); waitq_timeout: if (ret) { /* -- 2.43.5