From: Christoph Hellwig <hch@lst.de>
To: "Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>
Cc: "maximmi@mellanox.com" <maximmi@mellanox.com>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"konrad.wilk@oracle.com" <konrad.wilk@oracle.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"davem@davemloft.net" <davem@davemloft.net>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
"jonathan.lemon@gmail.com" <jonathan.lemon@gmail.com>,
"bpf@vger.kernel.org" <bpf@vger.kernel.org>,
"Björn Töpel" <bjorn.topel@intel.com>,
"Robin Murphy" <robin.murphy@arm.com>,
"Christoph Hellwig" <hch@lst.de>,
"magnus.karlsson@intel.com" <magnus.karlsson@intel.com>
Subject: Re: [PATCH net] xsk: remove cheap_dma optimization
Date: Wed, 8 Jul 2020 14:19:40 +0200 [thread overview]
Message-ID: <20200708121940.GA19619@lst.de> (raw)
In-Reply-To: <B926444035E5E2439431908E3842AFD255E99A@DGGEMI525-MBS.china.huawei.com>
On Wed, Jul 08, 2020 at 07:57:23AM +0000, Song Bao Hua (Barry Song) wrote:
> > int dma_map_batch_start(struct device *dev, size_t rounded_len,
> > enum dma_data_direction dir, unsigned long attrs, dma_addr_t *addr);
> > int dma_map_batch_add(struct device *dev, dma_addr_t *addr, struct page
> > *page,
> > unsigned long offset, size_t size);
> > int dma_map_batch_end(struct device *dev, int ret, dma_addr_t start_addr);
> >
>
> Hello Christoph,
>
> What is the different between dma_map_batch_add() and adding the buffer to sg of dma_map_sg()?
There is not struct scatterlist involved in this API, avoiding the
overhead to allocate it (which is kinda the point).
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next prev parent reply other threads:[~2020-07-08 12:19 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-26 13:43 [PATCH net] xsk: remove cheap_dma optimization Björn Töpel
2020-06-26 20:44 ` Jonathan Lemon
2020-06-26 23:00 ` Daniel Borkmann
2020-06-27 7:04 ` Christoph Hellwig
2020-06-28 17:16 ` Björn Töpel
2020-06-29 13:52 ` Daniel Borkmann
2020-06-29 15:10 ` Björn Töpel
2020-06-29 15:18 ` Daniel Borkmann
2020-06-29 16:23 ` Björn Töpel
2020-06-30 5:07 ` Christoph Hellwig
2020-06-30 13:47 ` Daniel Borkmann
2020-06-29 15:41 ` Robin Murphy
2020-07-01 10:17 ` Björn Töpel
2020-07-08 6:50 ` Christoph Hellwig
2020-07-08 7:57 ` Song Bao Hua (Barry Song)
2020-07-08 12:19 ` Christoph Hellwig [this message]
2020-07-08 13:18 ` Robin Murphy
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