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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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758d90e161
There are multiple places where arrays or otherwise variable sized buffer are allocated through V4L2 core code, including things like controls, memory pages, staging buffers for ioctls and so on. Such allocations can potentially require an order > 0 allocation from the page allocator, which is not guaranteed to be fulfilled and is likely to fail on a system with severe memory fragmentation (e.g. a system with very long uptime). Since the memory being allocated is intended to be used by the CPU exclusively, we can consider using vmalloc() as a fallback and this is exactly what the recently merged kvmalloc() helpers do. A kmalloc() call is still attempted, even for order > 0 allocations, but it is done with __GFP_NORETRY and __GFP_NOWARN, with expectation of failing if requested memory is not available instantly. Only then the vmalloc() fallback is used. This should give us fast and more reliable allocations even on systems with higher memory pressure and/or more fragmentation, while still retaining the same performance level on systems not suffering from such conditions. While at it, replace explicit array size calculations on changed allocations with kvmalloc_array(). Purposedly not touching videobuf1, as it is deprecated, has only few users remaining and would rather be seen removed instead. Signed-off-by: Tomasz Figa <tfiga@chromium.org> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> |
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| .. | ||
| Kconfig | ||
| Makefile | ||
| tuner-core.c | ||
| v4l2-async.c | ||
| v4l2-clk.c | ||
| v4l2-common.c | ||
| v4l2-compat-ioctl32.c | ||
| v4l2-ctrls.c | ||
| v4l2-dev.c | ||
| v4l2-device.c | ||
| v4l2-dv-timings.c | ||
| v4l2-event.c | ||
| v4l2-fh.c | ||
| v4l2-flash-led-class.c | ||
| v4l2-fwnode.c | ||
| v4l2-ioctl.c | ||
| v4l2-mc.c | ||
| v4l2-mem2mem.c | ||
| v4l2-subdev.c | ||
| v4l2-trace.c | ||
| vb2-trace.c | ||
| videobuf2-core.c | ||
| videobuf2-dma-contig.c | ||
| videobuf2-dma-sg.c | ||
| videobuf2-dvb.c | ||
| videobuf2-memops.c | ||
| videobuf2-v4l2.c | ||
| videobuf2-vmalloc.c | ||
| videobuf-core.c | ||
| videobuf-dma-contig.c | ||
| videobuf-dma-sg.c | ||
| videobuf-dvb.c | ||
| videobuf-vmalloc.c | ||