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Message-ID: <b435dd1d-c56f-4d56-9f73-30ee1ec99eac@arm.com>
Date: Mon, 3 Nov 2025 11:30:27 -0600
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Subject: Re: [PATCH 1/1] eal: correct memory ordering in MCS lock
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>,
 Tyler Retzlaff <roretzla@linux.microsoft.com>, dev@dpdk.org,
 Ola Liljedahl <ola.liljedahl@arm.com>, vattunuru@marvell.com
References: <20251023184724.1759497-1-wathsala.vithanage@arm.com>
 <f08a5a55-2a46-4f8c-9658-f7c320de57f2@arm.com>
 <20251103090717.2d181d95@phoenix>
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From: Wathsala Vithanage <wathsala.vithanage@arm.com>
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On 11/3/25 11:07, Stephen Hemminger wrote:
> On Mon, 3 Nov 2025 09:12:39 -0600
> Wathsala Vithanage <wathsala.vithanage@arm.com> wrote:
>
>> MCS lock is broken, it's just a matter of time it will run into a deadlock.
>>
>> drivers/dma/cnxk is a user of MCS lock.
> I am surprised that a driver would use mcslock.
> MCSlock is targeted at case of large number of CPU's with lots of contention.
> It will likely be slower than spinlock or ticketlock for the use case of driver.
It appears in |drivers/dma/cnxk/cnxk_dmadev_fp.c|, perhaps the 
maintainer can clarify.