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Date:   Tue, 15 Aug 2023 10:12:19 +0200
From:   Simon Horman <horms@kernel.org>
To:     Ratheesh Kannoth <rkannoth@marvell.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        kuba@kernel.org, pabeni@redhat.com, edumazet@google.com,
        aleksander.lobakin@intel.com, hawk@kernel.org,
        sgoutham@marvell.com, gakula@marvell.com, sbhatta@marvell.com,
        hkelam@marvell.com, davem@davemloft.net
Subject: Re: [PATCH v1 net] octeontx2-pf: fix page_pool creation fail for
 rings > 32k
Message-ID: <ZNszY4flVLCZWXT7@vergenet.net>
References: <20230814132411.2475687-1-rkannoth@marvell.com>
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In-Reply-To: <20230814132411.2475687-1-rkannoth@marvell.com>
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On Mon, Aug 14, 2023 at 06:54:11PM +0530, Ratheesh Kannoth wrote:

+ David S. Miller <davem@davemloft.net>
  Corrected address for Palao Abeni <pabeni@redhat.com>

> octeontx2 driver calls page_pool_create() during driver probe()
> and fails if queue size > 32k. Page pool infra uses these buffers
> as shock absorbers for burst traffic. These pages are pinned
> down as soon as page pool is created. As page pool does direct
> recycling way more aggressivelyi, often times ptr_ring is left

nit: aggressivelyi -> aggressively

> unused at all. Instead of clamping page_pool size to 32k at
> most, limit it even more to 2k to avoid wasting memory on much
> less used ptr_ring.
> 
> Fixes: b2e3406a38f0 ("octeontx2-pf: Add support for page pool")
> Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
> Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
> 
> ---
> 
> ChangeLogs:
> 
> v0->v1: Commit message changes.
> ---
> ---
>  drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c | 2 +-
>  drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h | 2 ++
>  2 files changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
> index 77c8f650f7ac..fc8a1220eb39 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c
> @@ -1432,7 +1432,7 @@ int otx2_pool_init(struct otx2_nic *pfvf, u16 pool_id,
>  	}
>  
>  	pp_params.flags = PP_FLAG_PAGE_FRAG | PP_FLAG_DMA_MAP;
> -	pp_params.pool_size = numptrs;
> +	pp_params.pool_size = OTX2_PAGE_POOL_SZ;
>  	pp_params.nid = NUMA_NO_NODE;
>  	pp_params.dev = pfvf->dev;
>  	pp_params.dma_dir = DMA_FROM_DEVICE;
> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h
> index ba8091131ec0..f6fea43617ff 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h
> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h
> @@ -30,6 +30,8 @@
>  #include <rvu_trace.h>
>  #include "qos.h"
>  
> +#define OTX2_PAGE_POOL_SZ 2048
> +
>  /* IPv4 flag more fragment bit */
>  #define IPV4_FLAG_MORE				0x20
>  
> -- 
> 2.25.1
> 
>