From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
To: "Mattias Rönnblom" <hofors@lysator.liu.se>,
"Morten Brørup" <mb@smartsharesystems.com>,
"Mattias Rönnblom" <mattias.ronnblom@ericsson.com>,
"dev@dpdk.org" <dev@dpdk.org>
Cc: "harry.van.haaren@intel.com" <harry.van.haaren@intel.com>,
nd <nd@arm.com>,
Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>,
nd <nd@arm.com>
Subject: RE: Service core statistics MT safety
Date: Mon, 27 Jun 2022 18:19:16 +0000 [thread overview]
Message-ID: <DBAPR08MB5814937DA34E1EC71B0762FA98B99@DBAPR08MB5814.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <0cfb2d19-ca59-fbba-c428-2e7629da43ec@lysator.liu.se>
<snip>
> >>
> >>> From: Mattias Rönnblom [mailto:mattias.ronnblom@ericsson.com]
> >>> Sent: Monday, 27 June 2022 13.06
> >>>
> >>> Hi.
> >>>
> >>> Is it safe to enable stats on MT safe services?
> >>>
> >>> https://github.com/DPDK/dpdk/blob/main/lib/eal/common/rte_service.c#
> >>> L3
> >>> 6
> >>> 6
> >>>
> >>> It seems to me this would have to be an __atomic_add for this code
> >>> to produce deterministic results.
> >>
> >> I agree. The same goes for the 'calls' field.
> > The calling function does the locking.
> > https://github.com/DPDK/dpdk/blob/main/lib/eal/common/rte_service.c#L3
> > 98
> >
> > For more information you can look at:
> > https://github.com/DPDK/dpdk/blob/main/lib/eal/include/rte_service.h#L
> > 120
> >
>
> What about the
> https://github.com/DPDK/dpdk/blob/main/lib/eal/common/rte_service.c#L404
> call (for MT safe services)?
>
> There's no lock held there.
Good point.
This is the case where the service running in service cores is MT safe. However, the stats are incremented outside of the MT Safety mechanism employed by the service. So, yes, this and other updates in the function 'service_runner_do_callback' need to be updated atomically.
next prev parent reply other threads:[~2022-06-27 18:19 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-27 11:05 Service core statistics MT safety Mattias Rönnblom
2022-06-27 12:31 ` Morten Brørup
2022-06-27 17:39 ` Honnappa Nagarahalli
2022-06-27 17:47 ` Mattias Rönnblom
2022-06-27 18:19 ` Honnappa Nagarahalli [this message]
2022-06-27 20:00 ` Mattias Rönnblom
2022-06-28 0:14 ` Honnappa Nagarahalli
2022-06-28 6:52 ` Mattias Rönnblom
2022-06-28 15:24 ` Honnappa Nagarahalli
2022-06-28 18:30 ` Mattias Rönnblom
2022-06-28 19:15 ` Honnappa Nagarahalli
2022-06-29 6:34 ` Mattias Rönnblom
2022-06-29 20:07 ` Honnappa Nagarahalli
2022-06-30 8:46 ` Van Haaren, Harry
2022-07-01 18:37 ` Honnappa Nagarahalli
2022-07-01 20:51 ` Morten Brørup
2022-07-05 17:09 ` Van Haaren, Harry
2022-07-07 17:26 ` Honnappa Nagarahalli
2022-07-08 12:58 ` Van Haaren, Harry
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