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Date:   Sun, 4 Apr 2021 13:37:55 +0300
From:   Leon Romanovsky <leon@kernel.org>
To:     Praveen Kumar Kannoju <praveen.kannoju@oracle.com>
Cc:     dledford@redhat.com, jgg@ziepe.ca, linux-rdma@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        rajesh.sivaramasubramaniom@oracle.com,
        rama.nichanamatlu@oracle.com, aruna.ramakrishna@oracle.com,
        jeffery.yoder@oracle.com
Subject: Re: [PATCH v3] IB/mlx5: Reduce max order of memory allocated for xlt
 update
Message-ID: <YGmXAyANXwRGosIe@unreal>
References: <1617425635-35631-1-git-send-email-praveen.kannoju@oracle.com>
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On Sat, Apr 03, 2021 at 04:53:55AM +0000, Praveen Kumar Kannoju wrote:
> To update xlt (during mlx5_ib_reg_user_mr()), the driver can request up to
> 1 MB (order-8) memory, depending on the size of the MR. This costly
> allocation can sometimes take very long to return (a few seconds). This
> causes the calling application to hang for a long time, especially when the
> system is fragmented.  To avoid these long latency spikes, the calls the
> higher order allocations need to fail faster in case they are not
> available. In order to acheive this we need __GFP_NORETRY flag in the
> gfp_mask before during fetching the free pages. This patch adds this flag
> to the mask.
> 
> Signed-off-by: Praveen Kumar Kannoju <praveen.kannoju@oracle.com>
> ---
>  drivers/infiniband/hw/mlx5/mr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Thanks a lot,
Acked-by: Leon Romanovsky <leonro@nvidia.com>