From: Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>
To: Phil Yang <Phil.Yang@arm.com>,
Harry van Haaren <harry.van.haaren@intel.com>,
Jerin Jacob <jerin.jacob@caviumnetworks.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"stable@dpdk.org" <stable@dpdk.org>, nd <nd@arm.com>
Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH] eal: fix lcore state bug
Date: Wed, 29 Apr 2020 23:32:10 +0200 [thread overview]
Message-ID: <ce173f19-031a-524e-ab0e-9b8a30348d38@partner.samsung.com> (raw)
In-Reply-To: <VE1PR08MB4640E98CDA50DF8427DA11D5E9AD0@VE1PR08MB4640.eurprd08.prod.outlook.com>
Hi Phil,
W dniu 29.04.2020 o 17:07, Phil Yang pisze:
> Hi Lukasz,
>
>> -----Original Message-----
>> From: dev <dev-bounces@dpdk.org> On Behalf Of Lukasz Wojciechowski
>> Sent: Tuesday, April 28, 2020 9:22 AM
>> To: Harry van Haaren <harry.van.haaren@intel.com>; Jerin Jacob
>> <jerin.jacob@caviumnetworks.com>
>> Cc: dev@dpdk.org; l.wojciechow@partner.samsung.com; stable@dpdk.org
>> Subject: [dpdk-dev] [PATCH] eal: fix lcore state bug
>>
>> The rte_service_lcore_reset_all function stops execution of services
>> on all lcores and switches them back from ROLE_SERVICE to ROLE_RTE.
>> However the thread loop for slave lcores (eal_thread_loop) distincts these
>> roles to set lcore state after processing delegated function.
>> It sets WAIT state for ROLE_SERVICE, but FINISHED for ROLE_RTE.
>> So changing the role to RTE before stopping work in slave lcores
>> causes lcores to end in FINISHED state. That is why the rte_eal_lcore_wait
>> must be run after rte_service_lcore_reset_all to bring back lcores to
>> launchable (WAIT) state.
> Is that make sense to call rte_eal_mp_wait_lcore() inside rte_serice_lcore_reset_all() ?
yeah, I thought about it and in my opinion the answer is no, because if
the function run on slave lcore is in FINISHED state it means, that
someone can still read the value returned by the function and the only
one who can be interested in the value is the one that delegated the
service.
If we will wait for lcores to end their jobs, read the values and switch
them to WAIT state, the values will be lost. The application might need
to read them. We cannot take this possibility from it.
> <snip>
>
> Thanks,
> Phil
--
Lukasz Wojciechowski
Principal Software Engineer
Samsung R&D Institute Poland
Samsung Electronics
Office +48 22 377 88 25
l.wojciechow@partner.samsung.com
next prev parent reply other threads:[~2020-04-29 21:32 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200428012204eucas1p120a84e501d0d64145c21476cd2562f36@eucas1p1.samsung.com>
2020-04-28 1:21 ` [dpdk-stable] " Lukasz Wojciechowski
2020-04-29 3:11 ` [dpdk-stable] [dpdk-dev] " Ruifeng Wang
2020-04-29 15:07 ` Phil Yang
2020-04-29 21:32 ` Lukasz Wojciechowski [this message]
2020-04-30 2:54 ` Phil Yang
2020-04-30 9:06 ` Lukasz Wojciechowski
2020-05-08 16:12 ` Van Haaren, Harry
2020-05-08 17:04 ` Lukasz Wojciechowski
2020-05-18 18:25 ` [dpdk-stable] " Lukasz Wojciechowski
2020-05-18 18:39 ` David Marchand
2020-05-18 18:43 ` Lukasz Wojciechowski
2020-05-20 11:40 ` Van Haaren, Harry
2020-05-20 12:47 ` Lukasz Wojciechowski
[not found] ` <CGME20200708133748eucas1p2dbe34d8605d8f618559daee9cbeaa73d@eucas1p2.samsung.com>
2020-07-08 13:37 ` [dpdk-stable] [PATCH v2] " Lukasz Wojciechowski
2020-07-08 14:52 ` Van Haaren, Harry
2020-07-08 17:10 ` David Marchand
2020-07-08 19:37 ` Lukasz Wojciechowski
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ce173f19-031a-524e-ab0e-9b8a30348d38@partner.samsung.com \
--to=l.wojciechow@partner.samsung.com \
--cc=Phil.Yang@arm.com \
--cc=dev@dpdk.org \
--cc=harry.van.haaren@intel.com \
--cc=jerin.jacob@caviumnetworks.com \
--cc=nd@arm.com \
--cc=stable@dpdk.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).