2021-01-21 12:52:44

by Jens Axboe

[permalink] [raw]
Subject: Re: [PATCH] lightnvm: fix memory leak when submit fails

On 1/21/21 12:22 AM, Pan Bian wrote:
> The allocated page is not released if error occurs in
> nvm_submit_io_sync_raw(). __free_page() is moved ealier to avoid
> possible memory leak issue.

Applied, thanks.

General question for Matias - is lightnvm maintained anymore at all, or
should we remove it? The project seems dead from my pov, and I don't
even remember anyone even reviewing fixes from other people.

--
Jens Axboe


2021-01-21 13:34:00

by Javier González

[permalink] [raw]
Subject: Re: [PATCH] lightnvm: fix memory leak when submit fails

On 21.01.2021 05:47, Jens Axboe wrote:
>On 1/21/21 12:22 AM, Pan Bian wrote:
>> The allocated page is not released if error occurs in
>> nvm_submit_io_sync_raw(). __free_page() is moved ealier to avoid
>> possible memory leak issue.
>
>Applied, thanks.
>
>General question for Matias - is lightnvm maintained anymore at all, or
>should we remove it? The project seems dead from my pov, and I don't
>even remember anyone even reviewing fixes from other people.
>

At least from the pblk side, I have no objections to removing it. I test
briefly that pblk runs on new releases, but there are no new features or
known bug fixes coming in.

Current deployments - to the best of my knowledge - are forks, which are
not being retrofitted upstream.

For completeness, I get a number of questions and request primarily from
the academia. These people will probably accuse the lack of LightNVM. I
understand though that this is not an argument to keep it.

Javier

2021-01-21 14:00:14

by Matias Bjørling

[permalink] [raw]
Subject: Re: [PATCH] lightnvm: fix memory leak when submit fails

On 21/01/2021 13.47, Jens Axboe wrote:
> On 1/21/21 12:22 AM, Pan Bian wrote:
>> The allocated page is not released if error occurs in
>> nvm_submit_io_sync_raw(). __free_page() is moved ealier to avoid
>> possible memory leak issue.
> Applied, thanks.
>
> General question for Matias - is lightnvm maintained anymore at all, or
> should we remove it? The project seems dead from my pov, and I don't
> even remember anyone even reviewing fixes from other people.
>
Hi Jens,

ZNS has superseded OCSSD/lightnvm. As a result, the hardware and
software development around OCSSD have also moved on to ZNS. To my
knowledge, there is not anyone implementing OCSSD1.2/2.0 commercially at
this point, and what has been deployed in production does not utilize
the Linux kernel stack.

I do not mind continuing to keep an eye on it, but on the other hand, it
has served its purpose. It enabled the "Open-Channel SSD architectures"
of the world to take hold in the market and thereby gained enough
momentum to be standardized in NVMe as ZNS.

Would you like me to send a PR to remove lightnvm immediately, or should
we mark it as deprecated for a while before pulling it?

Best, Matias


2021-01-21 17:05:00

by Heiner Litz

[permalink] [raw]
Subject: Re: [PATCH] lightnvm: fix memory leak when submit fails

I don't think that ZNS supersedes OCSSD. OCSSDs provide much more
flexibility and device control and remain valuable for academia. For
us, PBLK is the most accurate "SSD Emulator" out there that, as
another benefit, enables real-time performance measurements.
That being said, I understand that this may not be a good enough
reason to keep it around, but I wouldn't mind if it stayed for another
while.

On Thu, Jan 21, 2021 at 5:57 AM Matias Bjørling <[email protected]> wrote:
>
> On 21/01/2021 13.47, Jens Axboe wrote:
> > On 1/21/21 12:22 AM, Pan Bian wrote:
> >> The allocated page is not released if error occurs in
> >> nvm_submit_io_sync_raw(). __free_page() is moved ealier to avoid
> >> possible memory leak issue.
> > Applied, thanks.
> >
> > General question for Matias - is lightnvm maintained anymore at all, or
> > should we remove it? The project seems dead from my pov, and I don't
> > even remember anyone even reviewing fixes from other people.
> >
> Hi Jens,
>
> ZNS has superseded OCSSD/lightnvm. As a result, the hardware and
> software development around OCSSD have also moved on to ZNS. To my
> knowledge, there is not anyone implementing OCSSD1.2/2.0 commercially at
> this point, and what has been deployed in production does not utilize
> the Linux kernel stack.
>
> I do not mind continuing to keep an eye on it, but on the other hand, it
> has served its purpose. It enabled the "Open-Channel SSD architectures"
> of the world to take hold in the market and thereby gained enough
> momentum to be standardized in NVMe as ZNS.
>
> Would you like me to send a PR to remove lightnvm immediately, or should
> we mark it as deprecated for a while before pulling it?
>
> Best, Matias
>
>