From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
brouer@redhat.com, Robin Murphy <robin.murphy@arm.com>,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
linuxppc-dev@lists.ozlabs.org
Subject: Re: generic DMA bypass flag v4
Date: Fri, 10 Jul 2020 15:26:58 +0200 [thread overview]
Message-ID: <20200710152658.31a9391a@carbon> (raw)
In-Reply-To: <20200708152449.316476-1-hch@lst.de>
On Wed, 8 Jul 2020 17:24:44 +0200
Christoph Hellwig <hch@lst.de> wrote:
> Note that as-is this breaks the XSK buffer pool, which unfortunately
> poked directly into DMA internals. A fix for that is already queued
> up in the netdev tree.
>
> Jesper and XDP gang: this should not regress any performance as
> the dma-direct calls are now inlined into the out of line DMA mapping
> calls. But if you can verify the performance numbers that would be
> greatly appreciated.
From a superficial review of the patches, they look okay to me. I don't
have time to run a performance benchmark (before I go on vacation).
I hoped Björn could test/benchmark this(?), given (as mentioned) this
also affect XSK / AF_XDP performance.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: "Daniel Borkmann" <daniel@iogearbox.net>,
"Alexey Kardashevskiy" <aik@ozlabs.ru>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Joerg Roedel" <joro@8bytes.org>,
brouer@redhat.com, "Robin Murphy" <robin.murphy@arm.com>,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
"Björn Töpel" <bjorn.topel@gmail.com>,
linuxppc-dev@lists.ozlabs.org,
"Lu Baolu" <baolu.lu@linux.intel.com>
Subject: Re: generic DMA bypass flag v4
Date: Fri, 10 Jul 2020 15:26:58 +0200 [thread overview]
Message-ID: <20200710152658.31a9391a@carbon> (raw)
In-Reply-To: <20200708152449.316476-1-hch@lst.de>
On Wed, 8 Jul 2020 17:24:44 +0200
Christoph Hellwig <hch@lst.de> wrote:
> Note that as-is this breaks the XSK buffer pool, which unfortunately
> poked directly into DMA internals. A fix for that is already queued
> up in the netdev tree.
>
> Jesper and XDP gang: this should not regress any performance as
> the dma-direct calls are now inlined into the out of line DMA mapping
> calls. But if you can verify the performance numbers that would be
> greatly appreciated.
From a superficial review of the patches, they look okay to me. I don't
have time to run a performance benchmark (before I go on vacation).
I hoped Björn could test/benchmark this(?), given (as mentioned) this
also affect XSK / AF_XDP performance.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
WARNING: multiple messages have this Message-ID (diff)
From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org,
"Alexey Kardashevskiy" <aik@ozlabs.ru>,
linuxppc-dev@lists.ozlabs.org,
"Lu Baolu" <baolu.lu@linux.intel.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Joerg Roedel" <joro@8bytes.org>,
"Robin Murphy" <robin.murphy@arm.com>,
"Björn Töpel" <bjorn.topel@gmail.com>,
"Daniel Borkmann" <daniel@iogearbox.net>,
linux-kernel@vger.kernel.org, brouer@redhat.com
Subject: Re: generic DMA bypass flag v4
Date: Fri, 10 Jul 2020 15:26:58 +0200 [thread overview]
Message-ID: <20200710152658.31a9391a@carbon> (raw)
In-Reply-To: <20200708152449.316476-1-hch@lst.de>
On Wed, 8 Jul 2020 17:24:44 +0200
Christoph Hellwig <hch@lst.de> wrote:
> Note that as-is this breaks the XSK buffer pool, which unfortunately
> poked directly into DMA internals. A fix for that is already queued
> up in the netdev tree.
>
> Jesper and XDP gang: this should not regress any performance as
> the dma-direct calls are now inlined into the out of line DMA mapping
> calls. But if you can verify the performance numbers that would be
> greatly appreciated.
From a superficial review of the patches, they look okay to me. I don't
have time to run a performance benchmark (before I go on vacation).
I hoped Björn could test/benchmark this(?), given (as mentioned) this
also affect XSK / AF_XDP performance.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2020-07-10 13:27 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-08 15:24 generic DMA bypass flag v4 Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-08 15:24 ` [PATCH 1/5] dma-mapping: move the remaining DMA API calls out of line Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-08 15:24 ` [PATCH 2/5] dma-mapping: inline the fast path dma-direct calls Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-08 15:24 ` [PATCH 3/5] dma-mapping: make support for dma ops optional Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-09 18:10 ` kernel test robot
2020-07-18 17:17 ` Guenter Roeck
2020-07-18 17:17 ` Guenter Roeck
2020-07-18 17:17 ` Guenter Roeck
2020-07-20 6:20 ` Christoph Hellwig
2020-07-20 6:20 ` Christoph Hellwig
2020-07-20 6:20 ` Christoph Hellwig
2020-07-08 15:24 ` [PATCH 4/5] dma-mapping: add a dma_ops_bypass flag to struct device Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-13 4:59 ` Alexey Kardashevskiy
2020-07-13 4:59 ` Alexey Kardashevskiy
2020-07-13 4:59 ` Alexey Kardashevskiy
2020-07-14 7:07 ` Christoph Hellwig
2020-07-14 7:07 ` Christoph Hellwig
2020-07-14 7:07 ` Christoph Hellwig
2020-07-14 7:12 ` Alexey Kardashevskiy
2020-07-14 7:12 ` Alexey Kardashevskiy
2020-07-14 7:12 ` Alexey Kardashevskiy
2020-07-08 15:24 ` [PATCH 5/5] powerpc: use the generic dma_ops_bypass mode Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-07-08 15:24 ` Christoph Hellwig
2020-08-30 9:04 ` Cédric Le Goater
2020-08-30 9:04 ` Cédric Le Goater
2020-08-30 9:04 ` Cédric Le Goater
2020-08-31 6:40 ` Christoph Hellwig
2020-08-31 6:40 ` Christoph Hellwig
2020-08-31 6:40 ` Christoph Hellwig
2020-08-31 7:19 ` Cédric Le Goater
2020-08-31 7:19 ` Cédric Le Goater
2020-08-31 7:19 ` Cédric Le Goater
2020-09-05 15:45 ` Alexey Kardashevskiy
2020-09-05 15:45 ` Alexey Kardashevskiy
2020-09-05 15:45 ` Alexey Kardashevskiy
2020-07-10 13:26 ` Jesper Dangaard Brouer [this message]
2020-07-10 13:26 ` generic DMA bypass flag v4 Jesper Dangaard Brouer
2020-07-10 13:26 ` Jesper Dangaard Brouer
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