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Message-ID: <20101026170434.GA6246@mcarlson.broadcom.com>
Date: Tue, 26 Oct 2010 10:04:34 -0700
From: "Matt Carlson" <mcarlson@...adcom.com>
To: "Eric Dumazet" <eric.dumazet@...il.com>
cc: "Amit Salecha" <amit.salecha@...gic.com>,
"Matthew Carlson" <mcarlson@...adcom.com>,
"davem@...emloft.net" <davem@...emloft.net>,
"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
"Ameen Rahman" <ameen.rahman@...gic.com>,
"Anirban Chakraborty" <anirban.chakraborty@...gic.com>,
"Michael Chan" <mchan@...adcom.com>
Subject: Re: [PATCH net-next-2.6] tg3: use dma_alloc_coherent() instead
of pci_alloc_consistent()
On Tue, Oct 26, 2010 at 05:03:13AM -0700, Eric Dumazet wrote:
> Le mardi 26 octobre 2010 ?? 12:30 +0200, Eric Dumazet a ??crit :
>
> > By the way, you should use dma_alloc_coherent() instead of
> > pci_alloc_consistent() so that you can use GFP_KERNEL allocations
> > instead of GFP_ATOMIC, it might help in low memory conditions (if you
> > dont hold a spinlock at this point)
> >
>
> tg3 being often used as a reference network driver, I believe we should
> change its allocations before too many people copy paste suboptimal
> pci_alloc_consistent() stuff...
>
> Matt, could you please queue this patch and submit it to David when
> net-next-2.6 reopens ?
Sure. Thanks for the patch.
> Thanks
>
> [PATCH] tg3: use dma_alloc_coherent() instead of pci_alloc_consistent()
>
> Using dma_alloc_coherent() permits to use GFP_KERNEL allocations instead
> of GFP_ATOMIC ones. Its better when a machine is out of memory, because
> this allows driver to sleep to get its memory and succeed its init,
> especially when allocating high order pages.
>
> Signed-off-by: Eric Dumazet <eric.dumazet@...il.com>
> CC: Matt Carlson <mcarlson@...adcom.com>
> CC: Michael Chan <mchan@...adcom.com>
> ---
> drivers/net/tg3.c | 73 ++++++++++++++++++++++++--------------------
> 1 file changed, 41 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
> index 852e917..7dfa579 100644
> --- a/drivers/net/tg3.c
> +++ b/drivers/net/tg3.c
> @@ -6339,13 +6339,13 @@ static void tg3_rx_prodring_fini(struct tg3 *tp,
> kfree(tpr->rx_jmb_buffers);
> tpr->rx_jmb_buffers = NULL;
> if (tpr->rx_std) {
> - pci_free_consistent(tp->pdev, TG3_RX_STD_RING_BYTES(tp),
> - tpr->rx_std, tpr->rx_std_mapping);
> + dma_free_coherent(&tp->pdev->dev, TG3_RX_STD_RING_BYTES(tp),
> + tpr->rx_std, tpr->rx_std_mapping);
> tpr->rx_std = NULL;
> }
> if (tpr->rx_jmb) {
> - pci_free_consistent(tp->pdev, TG3_RX_JMB_RING_BYTES(tp),
> - tpr->rx_jmb, tpr->rx_jmb_mapping);
> + dma_free_coherent(&tp->pdev->dev, TG3_RX_JMB_RING_BYTES(tp),
> + tpr->rx_jmb, tpr->rx_jmb_mapping);
> tpr->rx_jmb = NULL;
> }
> }
> @@ -6358,8 +6358,10 @@ static int tg3_rx_prodring_init(struct tg3 *tp,
> if (!tpr->rx_std_buffers)
> return -ENOMEM;
>
> - tpr->rx_std = pci_alloc_consistent(tp->pdev, TG3_RX_STD_RING_BYTES(tp),
> - &tpr->rx_std_mapping);
> + tpr->rx_std = dma_alloc_coherent(&tp->pdev->dev,
> + TG3_RX_STD_RING_BYTES(tp),
> + &tpr->rx_std_mapping,
> + GFP_KERNEL);
> if (!tpr->rx_std)
> goto err_out;
>
> @@ -6370,9 +6372,10 @@ static int tg3_rx_prodring_init(struct tg3 *tp,
> if (!tpr->rx_jmb_buffers)
> goto err_out;
>
> - tpr->rx_jmb = pci_alloc_consistent(tp->pdev,
> - TG3_RX_JMB_RING_BYTES(tp),
> - &tpr->rx_jmb_mapping);
> + tpr->rx_jmb = dma_alloc_coherent(&tp->pdev->dev,
> + TG3_RX_JMB_RING_BYTES(tp),
> + &tpr->rx_jmb_mapping,
> + GFP_KERNEL);
> if (!tpr->rx_jmb)
> goto err_out;
> }
> @@ -6491,7 +6494,7 @@ static void tg3_free_consistent(struct tg3 *tp)
> struct tg3_napi *tnapi = &tp->napi[i];
>
> if (tnapi->tx_ring) {
> - pci_free_consistent(tp->pdev, TG3_TX_RING_BYTES,
> + dma_free_coherent(&tp->pdev->dev, TG3_TX_RING_BYTES,
> tnapi->tx_ring, tnapi->tx_desc_mapping);
> tnapi->tx_ring = NULL;
> }
> @@ -6500,25 +6503,26 @@ static void tg3_free_consistent(struct tg3 *tp)
> tnapi->tx_buffers = NULL;
>
> if (tnapi->rx_rcb) {
> - pci_free_consistent(tp->pdev, TG3_RX_RCB_RING_BYTES(tp),
> - tnapi->rx_rcb,
> - tnapi->rx_rcb_mapping);
> + dma_free_coherent(&tp->pdev->dev,
> + TG3_RX_RCB_RING_BYTES(tp),
> + tnapi->rx_rcb,
> + tnapi->rx_rcb_mapping);
> tnapi->rx_rcb = NULL;
> }
>
> tg3_rx_prodring_fini(tp, &tnapi->prodring);
>
> if (tnapi->hw_status) {
> - pci_free_consistent(tp->pdev, TG3_HW_STATUS_SIZE,
> - tnapi->hw_status,
> - tnapi->status_mapping);
> + dma_free_coherent(&tp->pdev->dev, TG3_HW_STATUS_SIZE,
> + tnapi->hw_status,
> + tnapi->status_mapping);
> tnapi->hw_status = NULL;
> }
> }
>
> if (tp->hw_stats) {
> - pci_free_consistent(tp->pdev, sizeof(struct tg3_hw_stats),
> - tp->hw_stats, tp->stats_mapping);
> + dma_free_coherent(&tp->pdev->dev, sizeof(struct tg3_hw_stats),
> + tp->hw_stats, tp->stats_mapping);
> tp->hw_stats = NULL;
> }
> }
> @@ -6531,9 +6535,10 @@ static int tg3_alloc_consistent(struct tg3 *tp)
> {
> int i;
>
> - tp->hw_stats = pci_alloc_consistent(tp->pdev,
> - sizeof(struct tg3_hw_stats),
> - &tp->stats_mapping);
> + tp->hw_stats = dma_alloc_coherent(&tp->pdev->dev,
> + sizeof(struct tg3_hw_stats),
> + &tp->stats_mapping,
> + GFP_KERNEL);
> if (!tp->hw_stats)
> goto err_out;
>
> @@ -6543,9 +6548,10 @@ static int tg3_alloc_consistent(struct tg3 *tp)
> struct tg3_napi *tnapi = &tp->napi[i];
> struct tg3_hw_status *sblk;
>
> - tnapi->hw_status = pci_alloc_consistent(tp->pdev,
> - TG3_HW_STATUS_SIZE,
> - &tnapi->status_mapping);
> + tnapi->hw_status = dma_alloc_coherent(&tp->pdev->dev,
> + TG3_HW_STATUS_SIZE,
> + &tnapi->status_mapping,
> + GFP_KERNEL);
> if (!tnapi->hw_status)
> goto err_out;
>
> @@ -6566,9 +6572,10 @@ static int tg3_alloc_consistent(struct tg3 *tp)
> if (!tnapi->tx_buffers)
> goto err_out;
>
> - tnapi->tx_ring = pci_alloc_consistent(tp->pdev,
> - TG3_TX_RING_BYTES,
> - &tnapi->tx_desc_mapping);
> + tnapi->tx_ring = dma_alloc_coherent(&tp->pdev->dev,
> + TG3_TX_RING_BYTES,
> + &tnapi->tx_desc_mapping,
> + GFP_KERNEL);
> if (!tnapi->tx_ring)
> goto err_out;
> }
> @@ -6601,9 +6608,10 @@ static int tg3_alloc_consistent(struct tg3 *tp)
> if (!i && (tp->tg3_flags3 & TG3_FLG3_ENABLE_RSS))
> continue;
>
> - tnapi->rx_rcb = pci_alloc_consistent(tp->pdev,
> - TG3_RX_RCB_RING_BYTES(tp),
> - &tnapi->rx_rcb_mapping);
> + tnapi->rx_rcb = dma_alloc_coherent(&tp->pdev->dev,
> + TG3_RX_RCB_RING_BYTES(tp),
> + &tnapi->rx_rcb_mapping,
> + GFP_KERNEL);
> if (!tnapi->rx_rcb)
> goto err_out;
>
> @@ -14159,7 +14167,8 @@ static int __devinit tg3_test_dma(struct tg3 *tp)
> u32 *buf, saved_dma_rwctrl;
> int ret = 0;
>
> - buf = pci_alloc_consistent(tp->pdev, TEST_BUFFER_SIZE, &buf_dma);
> + buf = dma_alloc_coherent(&tp->pdev->dev, TEST_BUFFER_SIZE,
> + &buf_dma, GFP_KERNEL);
> if (!buf) {
> ret = -ENOMEM;
> goto out_nofree;
> @@ -14343,7 +14352,7 @@ static int __devinit tg3_test_dma(struct tg3 *tp)
> }
>
> out:
> - pci_free_consistent(tp->pdev, TEST_BUFFER_SIZE, buf, buf_dma);
> + dma_free_coherent(&tp->pdev->dev, TEST_BUFFER_SIZE, buf, buf_dma);
> out_nofree:
> return ret;
> }
>
>
>
--
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