linux-kernel - Re: [PATCH v6 5/5] io_uring: remove ring quiesce for io_uring

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Message-ID: <8a9adb78-d9bb-a511-e4c1-c94cca392c9b@kernel.dk>
Date:   Fri, 15 Jul 2022 10:00:17 -0600
From:   Jens Axboe <axboe@...nel.dk>
To:     Michal Koutný <mkoutny@...e.com>,
        Usama Arif <usama.arif@...edance.com>
Cc:     io-uring@...r.kernel.org, asml.silence@...il.com,
        linux-kernel@...r.kernel.org, fam.zheng@...edance.com
Subject: Re: [PATCH v6 5/5] io_uring: remove ring quiesce for
 io_uring_register

On 7/15/22 9:44 AM, Michal Koutn? wrote:
> Hello.
> 
> On Fri, Feb 04, 2022 at 02:51:17PM +0000, Usama Arif <usama.arif@...edance.com> wrote:
>> -	percpu_ref_resurrect(ref);
>> [...]
>> -		percpu_ref_reinit(&ctx->refs);
> 
> It seems to me that this patch could have also changed
> 
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -1911,7 +1911,7 @@ static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
>         ctx->dummy_ubuf->ubuf = -1UL;
> 
>         if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
> -                           PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
> +                           0, GFP_KERNEL))
>                 goto err;
> 
>         ctx->flags = p->flags;
> 
> Or are there any plans to still use the reinit/resurrect functionality
> of the percpu counter?

Ah yes indeed, good catch! Would you mind sending that as an actual
patch?

-- 
Jens Axboe