linux/dim: Do nothing if no time delta between samples

Add return value for dim_calc_stats. This is an indication for the
caller if curr_stats was assigned by the function. Avoid using
curr_stats un

linux/dim: Do nothing if no time delta between samples

Add return value for dim_calc_stats. This is an indication for the
caller if curr_stats was assigned by the function. Avoid using
curr_stats uninitialized over {rdma/net}_dim, when no time delta between
samples. Coverity reported this potential use of an uninitialized
variable.

Fixes: 4c4dbb4a7363 ("net/mlx5e: Move dynamic interrupt coalescing code to include/linux")
Fixes: cb3c7fd4f839 ("net/mlx5e: Support adaptive RX coalescing")
Signed-off-by: Roy Novich <[email protected]>
Reviewed-by: Aya Levin <[email protected]>
Reviewed-by: Saeed Mahameed <[email protected]>
Signed-off-by: Tariq Toukan <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Reviewed-by: Michal Kubiak <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

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Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"

This reverts commit 6a9dc5fd6170 ("lib: Revert use of fallthrough
pseudo-keyword in lib/")

Now that we can build arch/powerpc/boot/ fr

Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"

This reverts commit 6a9dc5fd6170 ("lib: Revert use of fallthrough
pseudo-keyword in lib/")

Now that we can build arch/powerpc/boot/ free of -Wimplicit-fallthrough,
re-enable these fixes for lib/.

Signed-off-by: Nick Desaulniers <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Miguel Ojeda <[email protected]>
Link: https://github.com/ClangBuiltLinux/linux/issues/236
Signed-off-by: Gustavo A. R. Silva <[email protected]>

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lib: Revert use of fallthrough pseudo-keyword in lib/

The following build error for powerpc64 was reported by Nathan Chancellor:

"$ scripts/config --file arch/powerpc/configs/powernv_defconfig -e

lib: Revert use of fallthrough pseudo-keyword in lib/

The following build error for powerpc64 was reported by Nathan Chancellor:

"$ scripts/config --file arch/powerpc/configs/powernv_defconfig -e KERNEL_XZ

$ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc64le-linux- distclean powernv_defconfig zImage
...
In file included from arch/powerpc/boot/../../../lib/decompress_unxz.c:234,
from arch/powerpc/boot/decompress.c:38:
arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c: In function 'dec_main':
arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c:586:4: error: 'fallthrough' undeclared (first use in this function)
586 | fallthrough;
| ^~~~~~~~~~~

This will end up affecting distribution configurations such as Debian
and OpenSUSE according to my testing. I am not sure what the solution
is, the PowerPC wrapper does not set -D__KERNEL__ so I am not sure
that compiler_attributes.h can be safely included."

In order to avoid these sort of problems, it seems that the best
solution is to use /* fall through */ comments instead of the
fallthrough pseudo-keyword macro in lib/, for now.

Reported-by: Nathan Chancellor <[email protected]>
Fixes: df561f6688fe ("treewide: Use fallthrough pseudo-keyword")
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Reviewed-and-tested-by: Nathan Chancellor <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through mar

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <[email protected]>

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linux/dim: Implement RDMA adaptive moderation (DIM)

RDMA DIM implements a different algorithm from net DIM and is based on
completions which is how we can implement interrupt moderation in RDMA.

Th

linux/dim: Implement RDMA adaptive moderation (DIM)

RDMA DIM implements a different algorithm from net DIM and is based on
completions which is how we can implement interrupt moderation in RDMA.

The algorithm optimizes for number of completions and ratio between
completions and events. In order to avoid long latencies, the
implementation performs fast reduction of moderation level when the
traffic changes.

Signed-off-by: Yamin Friedman <[email protected]>
Reviewed-by: Max Gurtovoy <[email protected]>
Reviewed-by: Sagi Grimberg <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

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