The patch titled
Subject: mm: slab: reduce the kmalloc() minimum alignment if DMA bouncing possible
has been added to the -mm mm-unstable branch. Its filename is
mm-slab-reduce-the-kmalloc-minimum-alignment-if-dma-bouncing-possible.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-slab-reduce-the-kmalloc-minimum-alignment-if-dma-bouncing-possible.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Catalin Marinas <catalin.marinas@xxxxxxx>
Subject: mm: slab: reduce the kmalloc() minimum alignment if DMA bouncing possible
Date: Mon, 12 Jun 2023 16:32:00 +0100
If an architecture opted in to DMA bouncing of unaligned kmalloc() buffers
(ARCH_WANT_KMALLOC_DMA_BOUNCE), reduce the minimum kmalloc() cache
alignment below cache-line size to ARCH_KMALLOC_MINALIGN.
Link: https://lkml.kernel.org/r/20230612153201.554742-17-catalin.marinas@xxxxxxx
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
Tested-by: Isaac J. Manjarres <isaacmanjarres@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Alasdair Kergon <agk@xxxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Saravana Kannan <saravanak@xxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slab_common.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/mm/slab_common.c~mm-slab-reduce-the-kmalloc-minimum-alignment-if-dma-bouncing-possible
+++ a/mm/slab_common.c
@@ -18,6 +18,7 @@
#include <linux/uaccess.h>
#include <linux/seq_file.h>
#include <linux/dma-mapping.h>
+#include <linux/swiotlb.h>
#include <linux/proc_fs.h>
#include <linux/debugfs.h>
#include <linux/kasan.h>
@@ -865,6 +866,10 @@ void __init setup_kmalloc_cache_index_ta
static unsigned int __kmalloc_minalign(void)
{
+#ifdef CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC
+ if (io_tlb_default_mem.nslabs)
+ return ARCH_KMALLOC_MINALIGN;
+#endif
return dma_get_cache_alignment();
}
_
Patches currently in -mm which might be from catalin.marinas@xxxxxxx are
mm-slab-decouple-arch_kmalloc_minalign-from-arch_dma_minalign.patch
dma-allow-dma_get_cache_alignment-to-be-overridden-by-the-arch-code.patch
mm-slab-simplify-create_kmalloc_cache-args-and-make-it-static.patch
mm-slab-limit-kmalloc-minimum-alignment-to-dma_get_cache_alignment.patch
drivers-base-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
drivers-gpu-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
drivers-usb-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
drivers-spi-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
dm-crypt-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
iio-core-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
arm64-allow-kmalloc-caches-aligned-to-the-smaller-cache_line_size.patch
dma-mapping-force-bouncing-if-the-kmalloc-size-is-not-cache-line-aligned.patch
iommu-dma-force-bouncing-if-the-size-is-not-cacheline-aligned.patch
mm-slab-reduce-the-kmalloc-minimum-alignment-if-dma-bouncing-possible.patch
arm64-enable-arch_want_kmalloc_dma_bounce-for-arm64.patch
