netdev - Re: [PATCH net 1/4] ice: Create a separate kthread to handle ptp extts work

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <0706dfce-bb57-dc31-23ce-51165b931609@intel.com>
Date:   Fri, 9 Dec 2022 09:07:08 -0800
From:   Tony Nguyen <anthony.l.nguyen@...el.com>
To:     Richard Cochran <richardcochran@...il.com>
CC:     <davem@...emloft.net>, <kuba@...nel.org>, <pabeni@...hat.com>,
        <edumazet@...gle.com>,
        Anatolii Gerasymenko <anatolii.gerasymenko@...el.com>,
        <netdev@...r.kernel.org>, Gurucharan G <gurucharanx.g@...el.com>
Subject: Re: [PATCH net 1/4] ice: Create a separate kthread to handle ptp
 extts work

On 12/7/2022 4:27 PM, Richard Cochran wrote:
> On Wed, Dec 07, 2022 at 01:10:37PM -0800, Tony Nguyen wrote:
>> From: Anatolii Gerasymenko <anatolii.gerasymenko@...el.com>
>>
>> ice_ptp_extts_work() and ice_ptp_periodic_work() are both scheduled on
>> the same kthread_worker pf.ptp.kworker. But, ice_ptp_periodic_work()
>> sends messages to AQ and waits for responses. This causes
>> ice_ptp_extts_work() to be blocked while waiting to be scheduled. This
>> causes problems with the reading of the incoming signal timestamps,
>> which disrupts a 100 Hz signal.
>>
>> Create an additional kthread_worker pf.ptp.kworker_extts to service only
>> ice_ptp_extts_work() as soon as possible.
> 
> Looks like this driver isn't using the do_aux_work callback.  That
> would provide a kthread worker for free.  Why not use that?

The author is no longer with Intel anymore; we have another developer 
who is looking into this. Will make the change or get back to you.

Thanks,
Tony