linux.git/lib/dim, branch v6.12.80

dimlib: use -y instead of -objs in Makefile

2024-09-02T03:43:40+00:00

*-objs suffix is reserved rather for (user-space) host programs while
usually *-y suffix is used for kernel drivers (although *-objs works for
that purpose for now).

Let's correct the old usages of *-objs in Makefiles.

Link: https://lkml.kernel.org/r/20240821155140.611514-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko 
Acked-by: Florian Fainelli 
Reviewed-by: Alexander Lobakin 
Cc: Rasmus Villemoes 
Cc: Tal Gilboa 
Signed-off-by: Andrew Morton

dim: add new interfaces for initialization and getting results

2024-06-26T00:15:06+00:00

DIM-related mode and work have been collected in one same place,
so new interfaces are added to provide convenience.

Signed-off-by: Heng Qi 
Reviewed-by: Simon Horman 
Link: https://patch.msgid.link/20240621101353.107425-5-hengqi@linux.alibaba.com
Signed-off-by: Jakub Kicinski

ethtool: provide customized dim profile management

2024-06-26T00:15:06+00:00

The NetDIM library, currently leveraged by an array of NICs, delivers
excellent acceleration benefits. Nevertheless, NICs vary significantly
in their dim profile list prerequisites.

Specifically, virtio-net backends may present diverse sw or hw device
implementation, making a one-size-fits-all parameter list impractical.
On Alibaba Cloud, the virtio DPU's performance under the default DIM
profile falls short of expectations, partly due to a mismatch in
parameter configuration.

I also noticed that ice/idpf/ena and other NICs have customized
profilelist or placed some restrictions on dim capabilities.

Motivated by this, I tried adding new params for "ethtool -C" that provides
a per-device control to modify and access a device's interrupt parameters.

Usage
========
The target NIC is named ethx.

Assume that ethx only declares support for rx profile setting
(with DIM_PROFILE_RX flag set in profile_flags) and supports modification
of usec and pkt fields.

1. Query the currently customized list of the device

$ ethtool -c ethx
...
rx-profile:
{.usec =   1, .pkts = 256, .comps = n/a,},
{.usec =   8, .pkts = 256, .comps = n/a,},
{.usec =  64, .pkts = 256, .comps = n/a,},
{.usec = 128, .pkts = 256, .comps = n/a,},
{.usec = 256, .pkts = 256, .comps = n/a,}
tx-profile:   n/a

2. Tune
$ ethtool -C ethx rx-profile 1,1,n_2,n,n_3,3,n_4,4,n_n,5,n
"n" means do not modify this field.
$ ethtool -c ethx
...
rx-profile:
{.usec =   1, .pkts =   1, .comps = n/a,},
{.usec =   2, .pkts = 256, .comps = n/a,},
{.usec =   3, .pkts =   3, .comps = n/a,},
{.usec =   4, .pkts =   4, .comps = n/a,},
{.usec = 256, .pkts =   5, .comps = n/a,}
tx-profile:   n/a

3. Hint
If the device does not support some type of customized dim profiles,
the corresponding "n/a" will display.

If the "n/a" field is being modified, -EOPNOTSUPP will be reported.

Signed-off-by: Heng Qi 
Reviewed-by: Simon Horman 
Link: https://patch.msgid.link/20240621101353.107425-4-hengqi@linux.alibaba.com
Signed-off-by: Jakub Kicinski

linux/dim: move useful macros to .h file

2024-06-26T00:15:06+00:00

Useful macros will be used effectively elsewhere.
These will be utilized in subsequent patches.

Signed-off-by: Heng Qi 
Reviewed-by: Simon Horman 
Link: https://patch.msgid.link/20240621101353.107425-2-hengqi@linux.alibaba.com
Signed-off-by: Jakub Kicinski

lib: Allow for the DIM library to be modular

2024-05-07T23:42:45+00:00

Allow the Dynamic Interrupt Moderation (DIM) library to be built as a
module. This is particularly useful in an Android GKI (Google Kernel
Image) configuration where everything is built as a module, including
Ethernet controller drivers. Having to build DIMLIB into the kernel
image with potentially no user is wasteful.

Signed-off-by: Florian Fainelli 
Reviewed-by: Alexander Lobakin 
Link: https://lore.kernel.org/r/20240506175040.410446-1-florian.fainelli@broadcom.com
Signed-off-by: Jakub Kicinski

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

2023-05-09T09:06:45+00:00

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 
Reviewed-by: Aya Levin 
Reviewed-by: Saeed Mahameed 
Signed-off-by: Tariq Toukan 
Reviewed-by: Leon Romanovsky 
Reviewed-by: Michal Kubiak 
Link: https://lore.kernel.org/r/20230507135743.138993-1-tariqt@nvidia.com
Signed-off-by: Paolo Abeni

dim: initialize all struct fields

2022-05-10T00:20:37+00:00

The W=2 build pointed out that the code wasn't initializing all the
variables in the dim_cq_moder declarations with the struct initializers.
The net change here is zero since these structs were already static
const globals and were initialized with zeros by the compiler, but
removing compiler warnings has value in and of itself.

lib/dim/net_dim.c: At top level:
lib/dim/net_dim.c:54:9: warning: missing initializer for field ‘comps’ of ‘const struct dim_cq_moder’ [-Wmissing-field-initializers]
   54 |         NET_DIM_RX_EQE_PROFILES,
      |         ^~~~~~~~~~~~~~~~~~~~~~~
In file included from lib/dim/net_dim.c:6:
./include/linux/dim.h:45:13: note: ‘comps’ declared here
   45 |         u16 comps;
      |             ^~~~~

and repeats for the tx struct, and once you fix the comps entry then
the cq_period_mode field needs the same treatment.

Use the commonly accepted style to indicate to the compiler that we
know what we're doing, and add a comma at the end of each struct
initializer to clean up the issue, and use explicit initializers
for the fields we are initializing which makes the compiler happy.

While here and fixing these lines, clean up the code slightly with
a fix for the super long lines by removing the word "_MODERATION" from a
couple defines only used in this file.

Fixes: f8be17b81d44 ("lib/dim: Fix -Wunused-const-variable warnings")
Signed-off-by: Jesse Brandeburg 
Link: https://lore.kernel.org/r/20220507011038.14568-1-jesse.brandeburg@intel.com
Signed-off-by: Jakub Kicinski

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

2020-11-18T20:15:17+00:00

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 
Tested-by: Nathan Chancellor 
Reviewed-by: Nathan Chancellor 
Reviewed-by: Gustavo A. R. Silva 
Reviewed-by: Miguel Ojeda 
Link: https://github.com/ClangBuiltLinux/linux/issues/236
Signed-off-by: Gustavo A. R. Silva

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

2020-08-24T21:17:44+00:00

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 
Fixes: df561f6688fe ("treewide: Use fallthrough pseudo-keyword")
Signed-off-by: Gustavo A. R. Silva 
Reviewed-and-tested-by: Nathan Chancellor 
Signed-off-by: Linus Torvalds

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

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

linux.git/lib/dim, branch v6.12.80

dimlib: use *-y instead of *-objs in Makefile

dim: add new interfaces for initialization and getting results

ethtool: provide customized dim profile management

linux/dim: move useful macros to .h file

lib: Allow for the DIM library to be modular

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

dim: initialize all struct fields

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

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

treewide: Use fallthrough pseudo-keyword

dimlib: use -y instead of -objs in Makefile