From: Catalin Marinas <catalin.marinas@arm.com>
To: Isaac Manjarres <isaacmanjarres@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Arnd Bergmann <arnd@arndb.de>, Christoph Hellwig <hch@lst.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
Ard Biesheuvel <ardb@kernel.org>,
Saravana Kannan <saravanak@google.com>,
Alasdair Kergon <agk@redhat.com>, Daniel Vetter <daniel@ffwll.ch>,
Joerg Roedel <joro@8bytes.org>, Mark Brown <broonie@kernel.org>,
Mike Snitzer <snitzer@kernel.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
linux-mm@kvack.org, iommu@lists.linux.dev,
linux-arm-kernel@lists.infradead.org,
Petr Tesarik <petrtesarik@huaweicloud.com>
Subject: Re: [PATCH v3 00/13] mm, dma, arm64: Reduce ARCH_KMALLOC_MINALIGN to 8
Date: Tue, 16 May 2023 18:19:43 +0100 [thread overview]
Message-ID: <ZGO7L9EyDEXU6zWf@arm.com> (raw)
In-Reply-To: <ZGKDWMqTt/f05AmG@google.com>
On Mon, May 15, 2023 at 12:09:12PM -0700, Isaac Manjarres wrote:
> On Wed, Apr 19, 2023 at 05:06:04PM +0100, Catalin Marinas wrote:
> > I rebased it locally but the last stumbling block is sorting out the
> > iommu bouncing. I was hoping Robin Murphy can lend a hand but he's been
> > busy with other bits. I'll repost the series at 6.4-rc1.
> Hey Catalin, just following up on this. I think it might be worthwhile
> to split this series into two series:
>
> Series 1: Decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN,
> and use the cacheline size to determine the minimum kmalloc
> alignment.
>
> Series 2: Lower the minimum kmalloc alignment to 8 bytes by adding
> support for using SWIOTLB to bounce unaligned kmalloc buffers for DMA
> transactions.
>
> Dividing the patches as such has the advantage of lowering the minimum
> kmalloc alignment to 64 bytes on many ARM64 systems while the work for
> lowering the minimum alignment to 8 bytes proceeds. This provides a
> noticeable decrease in the slab memory footprint (e.g. I observed a 15
> MB decrease in slab usage on a device I was using).
I attempted "series 1" some time ago and the discussion led to the
combined approach (i.e. don't bother with limiting kmalloc minimum
alignment to cache_line_size() but instead bounce those small buffers).
In my series, I still have this fallback in case there's no swiotlb
buffer.
I'll post a new series this week (including DMA bouncing) but I'll try
to move the bouncing towards the end of the series in case there are
more discussions around this, at least the first part could be picked
up.
--
Catalin
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next prev parent reply other threads:[~2023-05-16 17:20 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-06 22:01 [PATCH v3 00/13] mm, dma, arm64: Reduce ARCH_KMALLOC_MINALIGN to 8 Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 01/13] mm/slab: Decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 02/13] dma-mapping: Force bouncing if the kmalloc() size is not cacheline-aligned Catalin Marinas
2022-11-07 9:43 ` Christoph Hellwig
2022-11-06 22:01 ` [PATCH v3 03/13] iommu/dma: Force bouncing of the " Catalin Marinas
2022-11-07 9:46 ` Christoph Hellwig
2022-11-07 10:54 ` Catalin Marinas
2022-11-07 13:26 ` Robin Murphy
2022-11-08 10:51 ` Catalin Marinas
2022-11-08 11:40 ` Robin Murphy
2022-11-08 7:50 ` Christoph Hellwig
2022-11-14 23:23 ` Isaac Manjarres
2022-11-15 11:48 ` Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 04/13] mm/slab: Allow kmalloc() minimum alignment fallback to dma_get_cache_alignment() Catalin Marinas
[not found] ` <202211070812.BhGKB0Hd-lkp@intel.com>
2022-11-07 9:22 ` Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 05/13] mm/slab: Simplify create_kmalloc_cache() args and make it static Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 06/13] dma: Allow the smaller cache_line_size() returned by dma_get_cache_alignment() Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 07/13] drivers/base: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 08/13] drivers/gpu: " Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 09/13] drivers/usb: " Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 10/13] drivers/spi: " Catalin Marinas
2022-11-07 12:58 ` Mark Brown
2022-11-06 22:01 ` [PATCH v3 11/13] crypto: " Catalin Marinas
2022-11-07 2:22 ` Herbert Xu
2022-11-07 9:05 ` Catalin Marinas
2022-11-07 9:12 ` Herbert Xu
2022-11-07 9:38 ` Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 12/13] drivers/md: " Catalin Marinas
2022-11-06 22:01 ` [PATCH v3 13/13] dma: arm64: Add CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC and enable it for arm64 Catalin Marinas
2022-11-07 13:03 ` Robin Murphy
2022-11-07 14:38 ` Christoph Hellwig
2022-11-07 15:24 ` Robin Murphy
2022-11-08 9:52 ` Catalin Marinas
2022-11-08 10:03 ` Christoph Hellwig
2022-11-30 18:48 ` Isaac Manjarres
2022-11-30 23:32 ` Alexander Graf
2023-04-20 11:51 ` Petr Tesařík
2023-03-16 18:38 ` [PATCH v3 00/13] mm, dma, arm64: Reduce ARCH_KMALLOC_MINALIGN to 8 Isaac Manjarres
2023-04-19 16:06 ` Catalin Marinas
2023-04-20 9:52 ` Petr Tesarik
2023-04-20 17:43 ` Catalin Marinas
2023-05-15 19:09 ` Isaac Manjarres
2023-05-16 17:19 ` Catalin Marinas [this message]
2023-05-16 18:19 ` Isaac Manjarres
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