Re: [LSF/MM/BFP ATTEND] [LSF/MM/BFP TOPIC] Storage: Copy Offload

From: Hannes Reinecke <hare@suse.de>
To: "Chaitanya Kulkarni" <chaitanyak@nvidia.com>,
	"Javier González" <javier@javigon.com>
Cc: Johannes Thumshirn <Johannes.Thumshirn@wdc.com>,
	Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
	"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
	"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
	"dm-devel@redhat.com" <dm-devel@redhat.com>,
	"lsf-pc@lists.linux-foundation.org" 
	<lsf-pc@lists.linux-foundation.org>,
	"axboe@kernel.dk" <axboe@kernel.dk>,
	"msnitzer@redhat.com" <msnitzer@redhat.com>,
	"martin.petersen@oracle.com" <martin.petersen@oracle.com>,
	"roland@purestorage.com" <roland@purestorage.com>,
	"mpatocka@redhat.com" <mpatocka@redhat.com>,
	"kbusch@kernel.org" <kbusch@kernel.org>,
	"rwheeler@redhat.com" <rwheeler@redhat.com>,
	"hch@lst.de" <hch@lst.de>,
	"Frederick.Knight@netapp.com" <Frederick.Knight@netapp.com>,
	"zach.brown@ni.com" <zach.brown@ni.com>,
	"osandov@fb.com" <osandov@fb.com>,
	Adam Manzanares <a.manzanares@samsung.com>,
	SelvaKumar S <selvakuma.s1@samsung.com>,
	Nitesh Shetty <nj.shetty@samsung.com>,
	Kanchan Joshi <joshi.k@samsung.com>,
	Vincent Fu <vincent.fu@samsung.com>,
	Bart Van Assche <bvanassche@acm.org>
Subject: Re: [LSF/MM/BFP ATTEND] [LSF/MM/BFP TOPIC] Storage: Copy Offload
Date: Fri, 29 Oct 2021 07:51:03 +0200	[thread overview]
Message-ID: <ba6c099b-42bf-4c7d-a923-00e7758fc835@suse.de> (raw)
In-Reply-To: <2a65e231-11dd-d5cc-c330-90314f6a8eae@nvidia.com>

On 10/29/21 2:21 AM, Chaitanya Kulkarni wrote:
> On 10/7/21 11:49 PM, Javier González wrote:
>> External email: Use caution opening links or attachments
>>
>>
>> On 06.10.2021 10:33, Bart Van Assche wrote:
>>> On 10/6/21 3:05 AM, Javier González wrote:
>>>> I agree that the topic is complex. However, we have not been able to
>>>> find a clear path forward in the mailing list.
>>>
>>> Hmm ... really? At least Martin Petersen and I consider device mapper
>>> support essential. How about starting from Mikulas' patch series that
>>> supports the device mapper? See also
>>> https://lore.kernel.org/all/alpine.LRH.2.02.2108171630120.30363@file01.intranet.prod.int.rdu2.redhat.com/
>>>
> 
> When we add a new REQ_OP_XXX we need to make sure it will work with
> device mapper, so I agree with Bart and Martin.
> 
> Starting with Mikulas patches is a right direction as of now..
> 
>>
>> Thanks for the pointers. We are looking into Mikulas' patch - I agree
>> that it is a good start.
>>
>>>> What do you think about joining the call to talk very specific next
>>>> steps to get a patchset that we can start reviewing in detail.
>>>
>>> I can do that.
>>
>> Thanks. I will wait until Chaitanya's reply on his questions. We will
>> start suggesting some dates then.
>>
> 
> I think at this point we need to at least decide on having a first call
> focused on how to proceed forward with Mikulas approach  ...
> 
> Javier, can you please organize a call with people you listed in this
> thread earlier ?
> 
Also Keith presented his work on a simple zone-based remapping block 
device, which included an in-kernel copy offload facility.
Idea is to lift that as a standalone patch such that we can use it a 
fallback (ie software) implementation if no other copy offload mechanism 
is available.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
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