Re: [PATCH] alloc_tag: move memory_allocation_profiling_sysctls into .rodata

From: Suren Baghdasaryan

Date: Tue Dec 23 2025 - 14:36:10 EST


On Mon, Dec 15, 2025 at 7:47 AM Joel Granados <joel.granados@xxxxxxxxxx> wrote:
>
> Remove the change in file mode permissions done before initializing the
> sysctl. It is not necessary as the writing of the kernel variable will
> be blocked by the proc_mem_profiling_handler when writing is disallowed
> (also controlled by mem_profiling_support).

Right. When this code was written,
memory_allocation_profiling_sysctls.proc_handler was using
proc_do_static_key(), so this mode update was needed. But now that we
use proc_mem_profiling_handler(), it can be indeed removed.
Thanks for the cleanup!

>
> Signed-off-by: Joel Granados <joel.granados@xxxxxxxxxx>

Acked-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>

> ---
> lib/alloc_tag.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c
> index 27fee57a5c91db8067c05bff974a9e801e0ef6a0..846a5b5b44a4e5f530605c97a200e03260e73d77 100644
> --- a/lib/alloc_tag.c
> +++ b/lib/alloc_tag.c
> @@ -783,7 +783,7 @@ static int proc_mem_profiling_handler(const struct ctl_table *table, int write,
> }
>
>
> -static struct ctl_table memory_allocation_profiling_sysctls[] = {
> +static const struct ctl_table memory_allocation_profiling_sysctls[] = {
> {
> .procname = "mem_profiling",
> .data = &mem_alloc_profiling_key,
> @@ -798,9 +798,6 @@ static struct ctl_table memory_allocation_profiling_sysctls[] = {
>
> static void __init sysctl_init(void)
> {
> - if (!mem_profiling_support)
> - memory_allocation_profiling_sysctls[0].mode = 0444;
> -
> register_sysctl_init("vm", memory_allocation_profiling_sysctls);
> }
> #else /* CONFIG_SYSCTL */
>
> ---
> base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> change-id: 20251215-jag-alloc_tag_const-dc9d7c3f7a8f
>
> Best regards,
> --
> Joel Granados <joel.granados@xxxxxxxxxx>
>
>