Re: [PATCH] alloc_tag: remove sysctl prefix from mem_profiling boot parameter

[Kent Overstreet]

On Tue, Jan 13, 2026 at 03:27:35AM +0000, ranxiaokai627@xxxxxxx wrote:
> >On Fri, Jan 09, 2026 at 06:24:19AM +0000, ranxiaokai627@xxxxxxx wrote:
> >> From: Ran Xiaokai <ran.xiaokai@xxxxxxxxxx>
> >> 
> >> Boot parameters prefixed with "sysctl." are processed separately
> >> during the final stage of system initialization via kernel_init()->
> >> do_sysctl_args(). Since mem_profiling support should be parsed
> >> in early boot stage, it is unsuitable for centralized handling
> >> in do_sysctl_args().
> >> Also, when CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled,
> >> the sysctl.vm.mem_profiling entry is not writable and will cause
> >> a warning. To prevent duplicate processing of sysctl.vm.mem_profiling,
> >> rename the boot parameter to "mem_profiling".
> >> 
> >> Signed-off-by: Ran Xiaokai <ran.xiaokai@xxxxxxxxxx>
> >
> >How was this observed/detected?
> 
> Actually no kernel bug or funtional defect was observed through testing.
> Via code reading, i found after commit [1],
> boot parameters prefixed with sysctl is processed redundantly.

When bcachefs was in the kernel, I spent an inordinate amount of time in
code reviews trying to convince people that yes, they really do need to
be testing their code.

Strangely enough, I have never had this issue with project contributors
who did not come to the project by way of the kernel community... :)