From: Christoph Hellwig <hch@lst.de>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>,
robin.murphy@arm.com, vdumpa@nvidia.com, linux@armlinux.org.uk,
catalin.marinas@arm.com, will.deacon@arm.com, joro@8bytes.org,
m.szyprowski@samsung.com, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
tony@atomide.com
Subject: Re: [PATCH v2 RFC/RFT 1/5] ARM: dma-mapping: Add fallback normal page allocations
Date: Wed, 24 Apr 2019 21:26:52 +0200 [thread overview]
Message-ID: <20190424192652.GA29032@lst.de> (raw)
In-Reply-To: <20190424183310.GA6168@Asurada-Nvidia.nvidia.com>
On Wed, Apr 24, 2019 at 11:33:11AM -0700, Nicolin Chen wrote:
> I feel it's similar to my previous set, which did most of these
> internally except the renaming part. But Catalin had a concern
> that some platforms might have limits on CMA range [1]. Will it
> be still okay to do the fallback internally?
>
> [1: https://www.spinics.net/lists/arm-kernel/msg714295.html ]
Catalins statement is correct, but I don't see how it applies to
your patch. Your patch just ensures that the fallback we have
in most callers is uniformly applied everywhere. The non-iommu
callers will still need to select a specific zone and/or retry
just the page allocator with other flags if the CMA (or fallback)
page doesn't match what they need. dma-direct does this correctly
and I think the arm32 allocator does as well, although it is a bit
hard to follow sometimes.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: tony@atomide.com, catalin.marinas@arm.com, will.deacon@arm.com,
linux@armlinux.org.uk, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, robin.murphy@arm.com,
Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 RFC/RFT 1/5] ARM: dma-mapping: Add fallback normal page allocations
Date: Wed, 24 Apr 2019 21:26:52 +0200 [thread overview]
Message-ID: <20190424192652.GA29032@lst.de> (raw)
Message-ID: <20190424192652.Dgxkzy5oNkbzAv8001HNsa3LC4odDWzdh7ZvVWaP7Uo@z> (raw)
In-Reply-To: <20190424183310.GA6168@Asurada-Nvidia.nvidia.com>
On Wed, Apr 24, 2019 at 11:33:11AM -0700, Nicolin Chen wrote:
> I feel it's similar to my previous set, which did most of these
> internally except the renaming part. But Catalin had a concern
> that some platforms might have limits on CMA range [1]. Will it
> be still okay to do the fallback internally?
>
> [1: https://www.spinics.net/lists/arm-kernel/msg714295.html ]
Catalins statement is correct, but I don't see how it applies to
your patch. Your patch just ensures that the fallback we have
in most callers is uniformly applied everywhere. The non-iommu
callers will still need to select a specific zone and/or retry
just the page allocator with other flags if the CMA (or fallback)
page doesn't match what they need. dma-direct does this correctly
and I think the arm32 allocator does as well, although it is a bit
hard to follow sometimes.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: tony@atomide.com, catalin.marinas@arm.com, joro@8bytes.org,
will.deacon@arm.com, linux@armlinux.org.uk,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
robin.murphy@arm.com, Christoph Hellwig <hch@lst.de>,
linux-arm-kernel@lists.infradead.org, m.szyprowski@samsung.com
Subject: Re: [PATCH v2 RFC/RFT 1/5] ARM: dma-mapping: Add fallback normal page allocations
Date: Wed, 24 Apr 2019 21:26:52 +0200 [thread overview]
Message-ID: <20190424192652.GA29032@lst.de> (raw)
In-Reply-To: <20190424183310.GA6168@Asurada-Nvidia.nvidia.com>
On Wed, Apr 24, 2019 at 11:33:11AM -0700, Nicolin Chen wrote:
> I feel it's similar to my previous set, which did most of these
> internally except the renaming part. But Catalin had a concern
> that some platforms might have limits on CMA range [1]. Will it
> be still okay to do the fallback internally?
>
> [1: https://www.spinics.net/lists/arm-kernel/msg714295.html ]
Catalins statement is correct, but I don't see how it applies to
your patch. Your patch just ensures that the fallback we have
in most callers is uniformly applied everywhere. The non-iommu
callers will still need to select a specific zone and/or retry
just the page allocator with other flags if the CMA (or fallback)
page doesn't match what they need. dma-direct does this correctly
and I think the arm32 allocator does as well, although it is a bit
hard to follow sometimes.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-04-24 19:26 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-26 23:01 [PATCH v2 RFC/RFT 0/5] Save single pages from CMA area Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
[not found] ` <20190326230131.16275-1-nicoleotsuka-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 1/5] ARM: dma-mapping: Add fallback normal page allocations Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-04-24 15:06 ` Christoph Hellwig
2019-04-24 15:06 ` Christoph Hellwig
2019-04-24 15:06 ` Christoph Hellwig
[not found] ` <20190424150638.GA22191-jcswGhMUV9g@public.gmane.org>
2019-04-24 15:08 ` Christoph Hellwig
2019-04-24 15:08 ` Christoph Hellwig
2019-04-24 15:08 ` Christoph Hellwig
2019-04-24 15:08 ` Christoph Hellwig
2019-04-24 18:33 ` Nicolin Chen
2019-04-24 18:33 ` Nicolin Chen
2019-04-24 18:33 ` Nicolin Chen
2019-04-24 19:26 ` Christoph Hellwig [this message]
2019-04-24 19:26 ` Christoph Hellwig
2019-04-24 19:26 ` Christoph Hellwig
2019-04-24 19:38 ` Nicolin Chen
2019-04-24 19:38 ` Nicolin Chen
2019-04-24 19:38 ` Nicolin Chen
2019-04-30 15:24 ` Catalin Marinas
2019-04-30 15:24 ` Catalin Marinas
2019-04-30 15:24 ` Catalin Marinas
2019-05-02 13:26 ` Christoph Hellwig
2019-05-02 13:26 ` Christoph Hellwig
2019-05-02 13:26 ` Christoph Hellwig
2019-05-02 13:26 ` Christoph Hellwig
2019-04-26 20:21 ` Nicolin Chen
2019-04-26 20:21 ` Nicolin Chen
2019-04-26 20:21 ` Nicolin Chen
2019-04-26 20:25 ` Christoph Hellwig
2019-04-26 20:25 ` Christoph Hellwig
2019-04-26 20:25 ` Christoph Hellwig
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 2/5] dma-remap: Run alloc_pages() on failure Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 3/5] iommu: amd_iommu: Add fallback normal page allocations Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 4/5] arm64: dma-mapping: " Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-26 23:01 ` [PATCH v2 RFC/RFT 5/5] dma-contiguous: Do not allocate a single page from CMA area Nicolin Chen
2019-03-26 23:01 ` Nicolin Chen
2019-03-27 8:08 ` [PATCH v2 RFC/RFT 0/5] Save single pages " Christoph Hellwig
2019-03-27 8:08 ` Christoph Hellwig
2019-03-27 18:42 ` Nicolin Chen
2019-03-27 18:42 ` Nicolin Chen
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