> -----Original Message-----
> From: Eads, Gage <gage.e...@intel.com>
> Sent: Monday, July 22, 2019 10:35 PM
> To: Phil Yang (Arm Technology China) <phil.y...@arm.com>; dev@dpdk.org
> Cc: tho...@monjalon.net; jer...@marvell.com; hemant.agra...@nxp.com;
> Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>; Gavin Hu (Arm
> Technology China) <gavin...@arm.com>; nd <n...@arm.com>
> Subject: RE: [PATCH v5 3/3] eal/stack: enable lock-free stack for aarch64
>
> > diff --git a/lib/librte_stack/rte_stack_lf_stubs.h
> > b/lib/librte_stack/rte_stack_lf_stubs.h
> > new file mode 100644
> > index 0000000..d924bc6
> > --- /dev/null
> > +++ b/lib/librte_stack/rte_stack_lf_stubs.h
> > @@ -0,0 +1,59 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright(c) 2019 Arm Limited
> > + */
> > +
> > +#ifndef _RTE_STACK_LF_STUBS_H_
> > +#define _RTE_STACK_LF_STUBS_H_
> > +
> > +#include <rte_common.h>
> > +#include <rte_atomic.h>
> > +
> > +static __rte_always_inline unsigned int __rte_stack_lf_count(struct
> > +rte_stack *s) {
> > + /* stack_lf_push() and stack_lf_pop() do not update the list's
> > contents
> > + * and stack_lf->len atomically, which can cause the list to appear
> > + * shorter than it actually is if this function is called while other
> > + * threads are modifying the list.
> > + *
> > + * However, given the inherently approximate nature of the
> > get_count
> > + * callback -- even if the list and its size were updated atomically,
> > + * the size could change between when get_count executes and
> > when the
> > + * value is returned to the caller -- this is acceptable.
> > + *
> > + * The stack_lf->len updates are placed such that the list may appear
> > to
> > + * have fewer elements than it does, but will never appear to have
> > more
> > + * elements. If the mempool is near-empty to the point that this is a
> > + * concern, the user should consider increasing the mempool size.
> > + */
> > + return (unsigned int)rte_atomic64_read((rte_atomic64_t *)
> > + &s->stack_lf.used.len);
> > +}
>
> Since the stub functions are not functional, these comments should be
> removed and the function simply return 0. The rte_atomic.h include can be
> removed as well.
OK. Will do it. Thanks.
