Subject: Re: [PATCH 0/6] rds: rdma: Add ability to force GFP_NOIO

From: Zhu Yanjun <[email-masked]>
Date: Wed, 15 May 2024 12:25:22 +0200

在 2024/5/14 20:32, Haakon Bugge 写道:
> Hi Yanjun,
> 
> 
>> On 14 May 2024, at 14:02, Zhu Yanjun <[email-masked]> wrote:
>>
>>
>>
>> On 14.05.24 10:53, Zhu Yanjun wrote:
>>> On 13.05.24 14:53, Håkon Bugge wrote:
>>>> This series enables RDS and the RDMA stack to be used as a block I/O
>>>> device. This to support a filesystem on top of a raw block device
>>> This is to support a filesystem ... ?
>>
>> Sorry. my bad. I mean, normally rds is used to act as a communication protocol between Oracle databases. Now in this patch series, it seems that rds acts as a communication protocol to support a filesystem. So I am curious which filesystem that rds is supporting?
> 
> The peer here is a file-server which acts a block device. What Oracle calls a cell-server. The initiator here, is actually using XFS over an Oracle in-kernel pseudo-volume block device.

Thanks Haakon.
There is a link about GFP_NOFS and GFP_NOIO, 
https://lore.kernel.org/linux-fsdevel/[email-masked]/.

I am not sure if you have read this link or not. In this link, the 
writer has his ideas about GFP_NOFS and GFP_NOIO.

"
My interest in this is that I'd like to get rid of the FGP_NOFS flag. 
It'd also be good to get rid of the __GFP_FS flag since there's always 
demand for more GFP flags.  I have a git branch with some work in this 
area, so there's a certain amount of conference-driven development going 
on here too.

We could mutatis mutandi for GFP_NOIO, memalloc_noio_save/restore, 
__GFP_IO, etc, so maybe the block people are also interested.  I haven't 
looked into that in any detail though.  I guess we'll see what interest 
this topic gains.
"

Anyway, good luck!

Zhu Yanjun

> Thxs,  Håkon