From: Leon Romanovsky <leon@kernel.org>
To: Olaf.Krzikalla@dlr.de
Cc: linux-rdma@vger.kernel.org
Subject: Re: Understanding the allocation size of mlx5_alloc_buf
Date: Thu, 6 Jul 2023 19:47:48 +0300 [thread overview]
Message-ID: <20230706164748.GW6455@unreal> (raw)
In-Reply-To: <7f6a9b854205410eb45a665b1e84c0f2@dlr.de>
On Thu, Jul 06, 2023 at 12:48:46PM +0000, Olaf.Krzikalla@dlr.de wrote:
> Hi @all,
>
> creating connections via create_qp fails on our cluster for rather small numbers of processes (128 is working, 256 not) due to an out-of-memory error. I've tracked down the issue to an mlx5_alloc_buf call, which allocates ~500kB per call, which seems to be a lot.
>
> heaptrack tells me the following:
>
> 34.47M peak memory consumed over 92 calls from
> mlx5_alloc_buf
> in /usr/lib64/libibverbs/libmlx5-rdmav34.so
> 8.65M consumed over 16 calls from:
> create_qp
> in /usr/lib64/libibverbs/libmlx5-rdmav34.so
> mlx5_create_qp
> in /usr/lib64/libibverbs/libmlx5-rdmav34.so
> .
>
> Can anyone help me to understand, what causes a 500kB allocation in create_qp? Maybe it is some sort of a configuration issue, which I can handle somehow.
>
> Thanks for help and best regards
> Olaf Krzikalla
>
>
> System information:
> CentOS Linux 7 (Core)
> Linux 3.10.0-1160.88.1.el7.x86_64
Please contact your Nvidia support representative, you are talking about distro kernel
and not linux upstream.
Thanks
> CA 'mlx5_0'
> CA type: MT4123
> Number of ports: 1
> Firmware version: 20.33.1048
> Hardware version: 0
>
>
>
>
>
>
prev parent reply other threads:[~2023-07-06 16:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-06 12:48 Understanding the allocation size of mlx5_alloc_buf Olaf.Krzikalla
2023-07-06 16:47 ` Leon Romanovsky [this message]
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