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From: Paolo Bonzini <pbonzini@redhat.com>
To: Stefan Hajnoczi <stefanha@redhat.com>, qemu-devel@nongnu.org
Cc: "Fam Zheng" <fam@euphon.net>,
	"Philippe Mathieu-Daudé" <philmd@linaro.org>,
	"Kevin Wolf" <kwolf@redhat.com>,
	qemu-block@nongnu.org, "Hanna Reitz" <hreitz@redhat.com>
Subject: Re: [PATCH] block/nvme: use AIO_WAIT_WHILE_UNLOCKED()
Date: Tue, 4 Apr 2023 15:48:19 +0200	[thread overview]
Message-ID: <739d3d6b-8583-8ca5-edd5-36c1c881fc53@redhat.com> (raw)
In-Reply-To: <20230404112044.427062-1-stefanha@redhat.com>

On 4/4/23 13:20, Stefan Hajnoczi wrote:
> A few Admin Queue commands are submitted during nvme_file_open(). They
> are synchronous since device initialization cannot continue until the
> commands complete.
> 
> AIO_WAIT_WHILE() is currently used, but the block/nvme.c code actually
> doesn't rely on the AioContext lock. Replace it with
> AIO_WAIT_WHILE_UNLOCKED(NULL, condition). There is no change in behavior
> and the dependency on the AioContext lock is eliminated.
> 
> This is a step towards removing the AioContext lock.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>   block/nvme.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/block/nvme.c b/block/nvme.c
> index 5b744c2bda..829b9c04db 100644
> --- a/block/nvme.c
> +++ b/block/nvme.c
> @@ -512,7 +512,6 @@ static int nvme_admin_cmd_sync(BlockDriverState *bs, NvmeCmd *cmd)
>   {
>       BDRVNVMeState *s = bs->opaque;
>       NVMeQueuePair *q = s->queues[INDEX_ADMIN];
> -    AioContext *aio_context = bdrv_get_aio_context(bs);
>       NVMeRequest *req;
>       int ret = -EINPROGRESS;
>       req = nvme_get_free_req_nowait(q);
> @@ -521,7 +520,7 @@ static int nvme_admin_cmd_sync(BlockDriverState *bs, NvmeCmd *cmd)
>       }
>       nvme_submit_command(q, req, cmd, nvme_admin_cmd_sync_cb, &ret);
>   
> -    AIO_WAIT_WHILE(aio_context, ret == -EINPROGRESS);
> +    AIO_WAIT_WHILE_UNLOCKED(NULL, ret == -EINPROGRESS);
>       return ret;
>   }
> 


Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>



  parent reply	other threads:[~2023-04-04 13:49 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-04 11:20 [PATCH] block/nvme: use AIO_WAIT_WHILE_UNLOCKED() Stefan Hajnoczi
2023-04-04 11:46 ` Philippe Mathieu-Daudé
2023-04-04 13:48 ` Paolo Bonzini [this message]
2023-04-27 12:49 ` Kevin Wolf

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