From: Stephen Hemminger <stephen@networkplumber.org>
To: Ruifeng Wang <ruifeng.wang@arm.com>
Cc: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>,
Konstantin Ananyev <konstantin.ananyev@intel.com>,
dev@dpdk.org, david.marchand@redhat.com, thomas@monjalon.net,
jerinj@marvell.com, nd@arm.com, Gavin Hu <gavin.hu@arm.com>,
Steve Capper <steve.capper@arm.com>,
Ola Liljedahl <ola.liljedahl@arm.com>
Subject: Re: [dpdk-dev] [PATCH v3 2/2] ring: use wfe to wait for ring tail update on aarch64
Date: Wed, 28 Apr 2021 10:17:14 -0700 [thread overview]
Message-ID: <20210428101714.2e5da560@hermes.local> (raw)
In-Reply-To: <20210425055653.1509261-3-ruifeng.wang@arm.com>
On Sun, 25 Apr 2021 05:56:53 +0000
Ruifeng Wang <ruifeng.wang@arm.com> wrote:
> Instead of polling for tail to be updated, use wfe instruction.
>
> Signed-off-by: Gavin Hu <gavin.hu@arm.com>
> Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
> Reviewed-by: Steve Capper <steve.capper@arm.com>
> Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Looks ok to me, but it does raise an interesting question.
Shouldn't the original code have been using atomic load to look at ht->tail.
This another place where "volatile considered harmful" applies.
next prev parent reply other threads:[~2021-04-28 17:17 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-24 7:07 [dpdk-dev] [PATCH v1 0/2] Use WFE for spinlock and ring Gavin Hu
2020-04-24 7:07 ` [dpdk-dev] [PATCH v1 1/2] spinlock: use wfe to reduce contention on aarch64 Gavin Hu
2020-04-24 7:07 ` [dpdk-dev] [PATCH v1 2/2] ring: use wfe to wait for ring tail update " Gavin Hu
2020-04-24 13:23 ` Ananyev, Konstantin
2020-04-26 8:41 ` Gavin Hu
2020-04-24 14:46 ` Honnappa Nagarahalli
2020-04-26 8:33 ` Gavin Hu
2020-04-26 8:39 ` [dpdk-dev] [PATCH v2 0/2] Use WFE for spinlock and ring Gavin Hu
2020-05-01 9:47 ` Ananyev, Konstantin
2020-05-03 14:54 ` David Marchand
2020-05-03 21:31 ` Honnappa Nagarahalli
2020-09-25 14:30 ` David Marchand
2021-03-25 14:58 ` David Marchand
2021-04-25 6:06 ` Ruifeng Wang
2021-04-25 15:56 ` Thomas Monjalon
2020-04-26 8:39 ` [dpdk-dev] [PATCH v2 1/2] spinlock: use wfe to reduce contention on aarch64 Gavin Hu
2020-04-28 12:22 ` Jerin Jacob
2020-04-26 8:39 ` [dpdk-dev] [PATCH v2 2/2] ring: use wfe to wait for ring tail update " Gavin Hu
2021-04-25 5:56 ` [dpdk-dev] Use WFE for spinlock and ring Ruifeng Wang
2021-04-25 5:56 ` [dpdk-dev] [PATCH v3 1/2] spinlock: use wfe to reduce contention on aarch64 Ruifeng Wang
2021-04-25 5:56 ` [dpdk-dev] [PATCH v3 2/2] ring: use wfe to wait for ring tail update " Ruifeng Wang
2021-04-26 5:38 ` Jerin Jacob
2021-04-28 17:17 ` Stephen Hemminger [this message]
2021-04-29 14:35 ` Ruifeng Wang
2021-04-29 15:05 ` Stephen Hemminger
2021-05-07 8:25 ` Ruifeng Wang
2021-04-28 7:42 ` [dpdk-dev] Use WFE for spinlock and ring David Marchand
2021-04-28 9:30 ` Ruifeng Wang
2021-04-28 11:13 ` Thomas Monjalon
2021-04-29 14:28 ` Ruifeng Wang
2021-04-29 15:20 ` Thomas Monjalon
2021-04-30 9:16 ` Bruce Richardson
2021-04-30 13:41 ` Honnappa Nagarahalli
2021-04-30 14:19 ` Bruce Richardson
2021-05-07 10:18 ` Ruifeng Wang
2021-05-07 10:24 ` Bruce Richardson
2021-07-05 8:51 ` David Marchand
2021-07-05 10:21 ` Ruifeng Wang
2021-07-07 14:47 ` Stephen Hemminger
2021-07-08 9:41 ` Ruifeng Wang
2021-07-08 16:58 ` Honnappa Nagarahalli
2021-07-07 5:43 ` [dpdk-dev] [PATCH v4 0/3] " Ruifeng Wang
2021-07-07 5:43 ` [dpdk-dev] [PATCH v4 1/3] spinlock: use wfe to reduce contention on aarch64 Ruifeng Wang
2021-07-07 5:43 ` [dpdk-dev] [PATCH v4 2/3] ring: use wfe to wait for ring tail update " Ruifeng Wang
2021-07-07 5:43 ` [dpdk-dev] [PATCH v4 3/3] build: add option to enable wait until equal Ruifeng Wang
2021-07-07 12:15 ` David Marchand
2021-07-07 5:48 ` [dpdk-dev] [PATCH v4 0/3] Use WFE for spinlock and ring Ruifeng Wang
2021-07-07 5:48 ` [dpdk-dev] [PATCH v4 1/3] spinlock: use wfe to reduce contention on aarch64 Ruifeng Wang
2021-07-07 5:48 ` [dpdk-dev] [PATCH v4 2/3] ring: use wfe to wait for ring tail update " Ruifeng Wang
2021-07-07 5:48 ` [dpdk-dev] [PATCH v4 3/3] build: add option to enable wait until equal Ruifeng Wang
2021-07-07 6:32 ` Thomas Monjalon
2021-07-07 6:46 ` Ruifeng Wang
2021-07-07 12:27 ` Bruce Richardson
2021-07-07 12:36 ` Jerin Jacob
2021-07-08 6:25 ` Ruifeng Wang
2021-07-08 6:32 ` Jerin Jacob
2021-07-08 7:32 ` Thomas Monjalon
2021-07-08 9:21 ` Ruifeng Wang
2021-07-08 10:28 ` Thomas Monjalon
2021-07-09 18:39 ` [dpdk-dev] [PATCH v4 0/3] Use WFE for spinlock and ring Thomas Monjalon
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