Hi Honnappa,
> -----Original Message-----
> From: Honnappa Nagarahalli <[email protected]>
> Sent: Friday, April 24, 2020 10:46 PM
> To: Gavin Hu <[email protected]>; [email protected]
> Cc: nd <[email protected]>; [email protected];
> [email protected]; [email protected]; Ruifeng Wang
> <[email protected]>; Phil Yang <[email protected]>; Joyce Kong
> <[email protected]>; Honnappa Nagarahalli
> <[email protected]>; nd <[email protected]>
> Subject: RE: [PATCH v1 2/2] ring: use wfe to wait for ring tail update on
> aarch64
>
> <snip>
>
> Hi Gavin,
> There are other sync modes added to rte_ring library. Can you
> please extend this to other rte_pause() calls in the library?
I looked into the other two calls to rte_cause, they can't use the
rte_wait_until_equal_XX APIs simply.
Maybe new APIs are required?
Here is the 32-bit API for your reference:
rte_wait_until_equal_32(volatile uint32_t *addr, uint32_t expected, int
memorder)
>
> Thanks,
> Honnappa
>
> > Subject: [PATCH v1 2/2] ring: use wfe to wait for ring tail update on
> aarch64
> >
> > Instead of polling for tail to be updated, use wfe instruction.
> >
> > Signed-off-by: Gavin Hu <[email protected]>
> > Reviewed-by: Ruifeng Wang <[email protected]>
> > Reviewed-by: Steve Capper <[email protected]>
> > Reviewed-by: Ola Liljedahl <[email protected]>
> > Reviewed-by: Honnappa Nagarahalli <[email protected]>
> > ---
> > lib/librte_ring/rte_ring_c11_mem.h | 4 ++--
> > lib/librte_ring/rte_ring_generic.h | 3 +--
> > 2 files changed, 3 insertions(+), 4 deletions(-)
> >
> > diff --git a/lib/librte_ring/rte_ring_c11_mem.h
> > b/lib/librte_ring/rte_ring_c11_mem.h
> > index 0fb73a337..764d8f186 100644
> > --- a/lib/librte_ring/rte_ring_c11_mem.h
> > +++ b/lib/librte_ring/rte_ring_c11_mem.h
> > @@ -2,6 +2,7 @@
> > *
> > * Copyright (c) 2017,2018 HXT-semitech Corporation.
> > * Copyright (c) 2007-2009 Kip Macy [email protected]
> > + * Copyright (c) 2019 Arm Limited
> > * All rights reserved.
> > * Derived from FreeBSD's bufring.h
> > * Used as BSD-3 Licensed with permission from Kip Macy.
> > @@ -21,8 +22,7 @@ update_tail(struct rte_ring_headtail *ht, uint32_t
> > old_val, uint32_t new_val,
> > * we need to wait for them to complete
> > */
> > if (!single)
> > - while (unlikely(ht->tail != old_val))
> > - rte_pause();
> > + rte_wait_until_equal_relaxed_32(&ht->tail, old_val);
> >
> > __atomic_store_n(&ht->tail, new_val, __ATOMIC_RELEASE); } diff --
> > git a/lib/librte_ring/rte_ring_generic.h
> > b/lib/librte_ring/rte_ring_generic.h
> > index 953cdbbd5..682852783 100644
> > --- a/lib/librte_ring/rte_ring_generic.h
> > +++ b/lib/librte_ring/rte_ring_generic.h
> > @@ -23,8 +23,7 @@ update_tail(struct rte_ring_headtail *ht, uint32_t
> > old_val, uint32_t new_val,
> > * we need to wait for them to complete
> > */
> > if (!single)
> > - while (unlikely(ht->tail != old_val))
> > - rte_pause();
> > + rte_wait_until_equal_relaxed_32(&ht->tail, old_val);
> >
> > ht->tail = new_val;
> > }
> > --
> > 2.17.1
