Re: [PATCH v3 0/7] sysctl: Remove sentinel elements from arch

[Frank Scheiner <frank.scheiner@web.de>]

Dear Joel,

On 02.10.23 13:30, Joel Granados via B4 Relay wrote:
> [...]

I successfully "Build-n-Boot-to-login" tested the following patchset
(together with the ia64 patch from V2 changed to:

```
diff --git a/arch/ia64/kernel/crash.c b/arch/ia64/kernel/crash.c
index 88b3ce3e66cd..65b0781f83ab 100644
--- a/arch/ia64/kernel/crash.c
+++ b/arch/ia64/kernel/crash.c
@@ -232,7 +232,6 @@ static struct ctl_table kdump_ctl_table[] = {
  		.mode = 0644,
  		.proc_handler = proc_dointvec,
  	},
-	{ }
  };
  #endif

```

...) on top of v6.6-rc4 on my rx2620. I also applied the measurement
patch (commented the printk in `new_dir` and uncommented the if
conditional).

I used a bash arithmetic expression (`accum=$(( accum + n ))`) in your
script to calculate the total memory savings, because `calc` is not
available as package for Debian on ia64.

There are no memory savings for this configuration.

But using the measurement patch with the printk in `new_dir` uncommented
and the if conditional also uncommented I see the following savings (I
assume this is the same as your measurement patch because the other
configuration didn't yield any savings):

```
root@rx2620:~/bin# ./check-mem-savings.bash
64
[...]
64
5888
```

> Joel Granados (7):
>        S390: Remove now superfluous sentinel elem from ctl_table arrays
>        arm: Remove now superfluous sentinel elem from ctl_table arrays
>        arch/x86: Remove now superfluous sentinel elem from ctl_table arrays
>        x86/vdso: Remove now superfluous sentinel element from ctl_table array
>        riscv: Remove now superfluous sentinel element from ctl_table array
>        powerpc: Remove now superfluous sentinel element from ctl_table arrays
>        c-sky: Remove now superfluous sentinel element from ctl_talbe array
>
>   arch/arm/kernel/isa.c                     | 4 ++--
>   arch/arm64/kernel/armv8_deprecated.c      | 8 +++-----
>   arch/arm64/kernel/fpsimd.c                | 2 --
>   arch/arm64/kernel/process.c               | 1 -
>   arch/csky/abiv1/alignment.c               | 1 -
>   arch/powerpc/kernel/idle.c                | 1 -
>   arch/powerpc/platforms/pseries/mobility.c | 1 -
>   arch/riscv/kernel/vector.c                | 1 -
>   arch/s390/appldata/appldata_base.c        | 4 +---
>   arch/s390/kernel/debug.c                  | 1 -
>   arch/s390/kernel/topology.c               | 1 -
>   arch/s390/mm/cmm.c                        | 1 -
>   arch/s390/mm/pgalloc.c                    | 1 -
>   arch/x86/entry/vdso/vdso32-setup.c        | 1 -
>   arch/x86/kernel/cpu/intel.c               | 1 -
>   arch/x86/kernel/itmt.c                    | 1 -
>   drivers/perf/arm_pmuv3.c                  | 1 -
>   17 files changed, 6 insertions(+), 25 deletions(-)
> ---
> base-commit: 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa
> change-id: 20230904-jag-sysctl_remove_empty_elem_arch-81db0a6e6cc4

Tested-by: Frank Scheiner <frank.scheiner@web.de> # ia64

Cheers,
Frank