From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
To: Amit Prakash Shukla <amitprakashs@marvell.com>,
Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"jerinj@marvell.com" <jerinj@marvell.com>,
"stable@dpdk.org" <stable@dpdk.org>, nd <nd@arm.com>,
nd <nd@arm.com>
Subject: RE: [PATCH] ring: compilation fix with GCC-12
Date: Sat, 6 Aug 2022 18:35:25 +0000 [thread overview]
Message-ID: <DBAPR08MB58149CFBE86F8C3BA74D6F6B98619@DBAPR08MB5814.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <20220805090348.1947658-1-amitprakashs@marvell.com>
<snip>
>
> GCC 12 raises the following warning:
>
> In function '__rte_ring_dequeue_elems_128',
> inlined from '__rte_ring_dequeue_elems' at
> ../lib/ring/rte_ring_elem_pvt.h:262:3,
> inlined from '__rte_ring_do_hts_dequeue_elem' at
> ../lib/ring/rte_ring_hts_elem_pvt.h:237:3,
> inlined from 'rte_ring_mc_hts_dequeue_bulk_elem' at
> ../lib/ring/rte_ring_hts.h:83:9,
> inlined from 'rte_ring_dequeue_bulk_elem' at
> ../lib/ring/rte_ring_elem.h:391:10,
> inlined from 'rte_ring_dequeue_elem' at
> ../lib/ring/rte_ring_elem.h:476:9,
> inlined from 'rte_ring_dequeue' at
> ../lib/ring/rte_ring.h:463:9,
> inlined from 'rxa_intr_ring_dequeue' at
> ../lib/eventdev/rte_event_eth_rx_adapter.c:1196:10:
> ../lib/ring/rte_ring_elem_pvt.h:234:25: error: 'memcpy' writing
> 32 bytes into a region of size 8 overflows the destination
> [-Werror=stringop-overflow=]
> 234 | memcpy((void *)(obj + i), (void *)(ring + idx), 32);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Replacing memcpy with rte_memcpy fixes the GCC-12 compilation issue.
Any reason why this replacement fixes the problem?
Do you have any performance numbers with this change?
> Also it would be better to change to rte_memcpy as the function is called in
> fastpath.
On Arm platforms, memcpy in the later versions has the best performance.
>
> Bugzilla ID: 1062
> Fixes: 1fc73390bcf5 ("ring: refactor exported headers")
> Cc: stable@dpdk.org
>
> Signed-off-by: Amit Prakash Shukla <amitprakashs@marvell.com>
> ---
> lib/ring/rte_ring_elem_pvt.h | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/lib/ring/rte_ring_elem_pvt.h b/lib/ring/rte_ring_elem_pvt.h index
> 83788c56e6..3d85b13333 100644
> --- a/lib/ring/rte_ring_elem_pvt.h
> +++ b/lib/ring/rte_ring_elem_pvt.h
> @@ -10,6 +10,8 @@
> #ifndef _RTE_RING_ELEM_PVT_H_
> #define _RTE_RING_ELEM_PVT_H_
>
> +#include <rte_memcpy.h>
> +
> static __rte_always_inline void
> __rte_ring_enqueue_elems_32(struct rte_ring *r, const uint32_t size,
> uint32_t idx, const void *obj_table, uint32_t n) @@ -97,20
> +99,20 @@ __rte_ring_enqueue_elems_128(struct rte_ring *r, uint32_t
> prod_head,
> const rte_int128_t *obj = (const rte_int128_t *)obj_table;
> if (likely(idx + n <= size)) {
> for (i = 0; i < (n & ~0x1); i += 2, idx += 2)
> - memcpy((void *)(ring + idx),
> + rte_memcpy((void *)(ring + idx),
> (const void *)(obj + i), 32);
> switch (n & 0x1) {
> case 1:
> - memcpy((void *)(ring + idx),
> + rte_memcpy((void *)(ring + idx),
> (const void *)(obj + i), 16);
> }
> } else {
> for (i = 0; idx < size; i++, idx++)
> - memcpy((void *)(ring + idx),
> + rte_memcpy((void *)(ring + idx),
> (const void *)(obj + i), 16);
> /* Start at the beginning */
> for (idx = 0; i < n; i++, idx++)
> - memcpy((void *)(ring + idx),
> + rte_memcpy((void *)(ring + idx),
> (const void *)(obj + i), 16);
> }
> }
> @@ -231,17 +233,17 @@ __rte_ring_dequeue_elems_128(struct rte_ring *r,
> uint32_t prod_head,
> rte_int128_t *obj = (rte_int128_t *)obj_table;
> if (likely(idx + n <= size)) {
> for (i = 0; i < (n & ~0x1); i += 2, idx += 2)
> - memcpy((void *)(obj + i), (void *)(ring + idx), 32);
> + rte_memcpy((void *)(obj + i), (void *)(ring + idx), 32);
> switch (n & 0x1) {
> case 1:
> - memcpy((void *)(obj + i), (void *)(ring + idx), 16);
> + rte_memcpy((void *)(obj + i), (void *)(ring + idx), 16);
> }
> } else {
> for (i = 0; idx < size; i++, idx++)
> - memcpy((void *)(obj + i), (void *)(ring + idx), 16);
> + rte_memcpy((void *)(obj + i), (void *)(ring + idx), 16);
> /* Start at the beginning */
> for (idx = 0; i < n; i++, idx++)
> - memcpy((void *)(obj + i), (void *)(ring + idx), 16);
> + rte_memcpy((void *)(obj + i), (void *)(ring + idx), 16);
> }
> }
>
> --
> 2.25.1
next prev parent reply other threads:[~2022-08-06 18:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-05 9:03 Amit Prakash Shukla
2022-08-05 15:37 ` Stephen Hemminger
2022-08-06 18:35 ` Honnappa Nagarahalli [this message]
2022-08-07 12:26 ` Konstantin Ananyev
2022-08-23 9:38 ` [EXT] " Amit Prakash Shukla
2022-08-23 9:41 ` Amit Prakash Shukla
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