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From: Andrew Rybchenko <arybchenko@solarflare.com>
To: Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>,
	"Jerin Jacob Kollanukkaran" <jerinj@marvell.com>,
	"thomas@monjalon.net" <thomas@monjalon.net>,
	"ferruh.yigit@intel.com" <ferruh.yigit@intel.com>,
	"stephen@networkplumber.org" <stephen@networkplumber.org>
Cc: "dev@dpdk.org" <dev@dpdk.org>, "stable@dpdk.org" <stable@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] ethdev: fix DMA zone reserve not honoring size
Date: Mon, 1 Apr 2019 10:30:33 +0300	[thread overview]
Message-ID: <105f221f-0c64-e950-df9a-2c9eaa0991c3@solarflare.com> (raw)
Message-ID: <20190401073033.d8sKlRtJEnGp4jnNDWF86w7eUxC4VKJnN8n2m-EdX3g@z> (raw)
In-Reply-To: <20190331162437.13048-1-pbhagavatula@marvell.com>

On 3/31/19 7:25 PM, Pavan Nikhilesh Bhagavatula wrote:
> From: Pavan Nikhilesh <pbhagavatula@marvell.com>
>
> The `rte_eth_dma_zone_reserve()` is generally used to create HW rings.
> In some scenarios when a driver needs to reconfigure the ring size
> since the named memzone already exists it returns the previous memzone
> without checking if a different sized ring is requested.
>
> Introduce a check to see if the ring size requested is different from the
> previously created memzone length.
>
> Fixes: 719dbebceb81 ("xen: allow determining DOM0 at runtime")
> Cc: stable@dpdk.org
>
> Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
> ---
>   lib/librte_ethdev/rte_ethdev.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index 12b66b68c..4ae12e43b 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -3604,9 +3604,12 @@ rte_eth_dma_zone_reserve(const struct rte_eth_dev *dev, const char *ring_name,
>   	}
>   
>   	mz = rte_memzone_lookup(z_name);
> -	if (mz)
> +	if (mz && (mz->len == size))
>   		return mz;
>   
> +	if (mz)
> +		rte_memzone_free(mz);

NACK
I really don't like that API which should reserve does free if requested
size does not match previously allocated.
I understand the motivation, but I don't think the solution is correct.

> +
>   	return rte_memzone_reserve_aligned(z_name, size, socket_id,
>   			RTE_MEMZONE_IOVA_CONTIG, align);
>   }


  parent reply	other threads:[~2019-04-01  7:30 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-31 16:25 Pavan Nikhilesh Bhagavatula
2019-03-31 16:25 ` Pavan Nikhilesh Bhagavatula
2019-04-01  7:30 ` Andrew Rybchenko [this message]
2019-04-01  7:30   ` Andrew Rybchenko
2019-04-01  9:28   ` Burakov, Anatoly
2019-04-01  9:28     ` Burakov, Anatoly
2019-04-01  9:40     ` Burakov, Anatoly
2019-04-01  9:40       ` Burakov, Anatoly
2019-04-01 12:12       ` [dpdk-dev] [EXT] " Pavan Nikhilesh Bhagavatula
2019-04-01 12:12         ` Pavan Nikhilesh Bhagavatula
2019-04-02  0:47   ` Jerin Jacob Kollanukkaran
2019-04-02  0:47     ` Jerin Jacob Kollanukkaran
2019-04-02  7:36     ` Andrew Rybchenko
2019-04-02  7:36       ` Andrew Rybchenko
2019-04-02  8:25       ` Jerin Jacob Kollanukkaran
2019-04-02  8:25         ` Jerin Jacob Kollanukkaran
2019-04-02  8:44         ` Andrew Rybchenko
2019-04-02  8:44           ` Andrew Rybchenko
2019-04-04 22:23           ` Thomas Monjalon
2019-04-04 22:23             ` Thomas Monjalon
2019-04-05  8:03             ` Andrew Rybchenko
2019-04-05  8:03               ` Andrew Rybchenko

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