https://bugzilla.kernel.org/show_bug.cgi?id=215890 --- Comment #7 from Satadru Pramanik (satadru@xxxxxxxxx) --- After bisection: git bisect good f5ff79fddf0efecca538046b5cc20fb3ded2ec4f is the first bad commit commit f5ff79fddf0efecca538046b5cc20fb3ded2ec4f Author: Christoph Hellwig <hch@xxxxxx> Date: Sat Feb 26 16:40:21 2022 +0100 dma-mapping: remove CONFIG_DMA_REMAP CONFIG_DMA_REMAP is used to build a few helpers around the core vmalloc code, and to use them in case there is a highmem page in dma-direct, and to make dma coherent allocations be able to use non-contiguous pages allocations for DMA allocations in the dma-iommu layer. Right now it needs to be explicitly selected by architectures, and is only done so by architectures that require remapping to deal with devices that are not DMA coherent. Make it unconditional for builds with CONFIG_MMU as it is very little extra code, but makes it much more likely that large DMA allocations succeed on x86. This fixes hot plugging a NVMe thunderbolt SSD for me, which tries to allocate a 1MB buffer that is otherwise hard to obtain due to memory fragmentation on a heavily used laptop. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx> arch/arm/Kconfig | 2 +- arch/xtensa/Kconfig | 2 +- drivers/iommu/dma-iommu.c | 14 +++++--------- kernel/dma/Kconfig | 7 +------ kernel/dma/Makefile | 2 +- kernel/dma/direct.c | 18 +++++++----------- 6 files changed, 16 insertions(+), 29 deletions(-) -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
