From: Jerin Jacob Kollanukkaran <jerinj@marvell.com>
To: "Mattias Rönnblom" <mattias.ronnblom@ericsson.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"stefan.sundkvist@ericsson.com" <stefan.sundkvist@ericsson.com>,
"Ola.Liljedahl@arm.com" <Ola.Liljedahl@arm.com>
Subject: Re: [dpdk-dev] [PATCH 5/8] event/dsw: avoid migration waves in large systems
Date: Mon, 9 Mar 2020 07:17:05 +0000 [thread overview]
Message-ID: <BYAPR18MB2424DB4C7599FD28E2D6BD29C8FE0@BYAPR18MB2424.namprd18.prod.outlook.com> (raw)
> -----Original Message-----
> From: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> Sent: Monday, March 9, 2020 12:21 PM
> To: Jerin Jacob Kollanukkaran <jerinj@marvell.com>
> Cc: dev@dpdk.org; stefan.sundkvist@ericsson.com; Ola.Liljedahl@arm.com;
> Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> Subject: [PATCH 5/8] event/dsw: avoid migration waves in large systems
>
> ----------------------------------------------------------------------
> DSW limits the rate of migrations on a per-port basis. Hence, as the number of
> cores grows, so does the total migration capacity.
>
> In high core-count systems, this allows for a situation where flows are migrated
> to a lightly loaded port which recently already received a number of new flows
> (from other ports). The processing load generated by these new flows may not
> yet be reflected in the lightly loaded port's load estimate. The result is that the
> previously lightly loaded port is now overloaded.
>
> This patch adds a rough estimate of the size of the inbound migrations to a
> particular port, which can be factored into the migration logic, avoiding the
> above problem.
>
> Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> ---
> @@ -491,6 +502,9 @@ dsw_select_emigration_target(struct dsw_evdev *dsw,
> target_qfs[*targets_len] = *candidate_qf;
> (*targets_len)++;
>
> + rte_atomic32_add(&dsw->ports[candidate_port_id].immigration_load,
> + candidate_flow_load);
These are the full barriers in arm64 and PowerPC.
Request to change the C11 mem model[1] with Load and acquire semantics
For better performance enhancement on non x86 machines.
drivers/event/opdl is already moved to C11 mem model.
[1]
https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html
> +
> return true;
next reply other threads:[~2020-03-09 7:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-09 7:17 Jerin Jacob Kollanukkaran [this message]
2020-03-09 7:58 ` Mattias Rönnblom
2020-03-09 8:12 ` Jerin Jacob Kollanukkaran
2020-03-09 8:41 ` Mattias Rönnblom
-- strict thread matches above, loose matches on Subject: below --
2020-03-09 6:50 [dpdk-dev] [PATCH 0/8] DSW performance and statistics improvements Mattias Rönnblom
2020-03-09 6:51 ` [dpdk-dev] [PATCH 5/8] event/dsw: avoid migration waves in large systems Mattias Rönnblom
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