Hi Masami,
On Tue, Feb 11, 2025 at 11:47:03PM +0900, Masami Hiramatsu (Google) wrote:
> From: Masami Hiramatsu (Google) <mhira...@kernel.org>
>
> Add reserve_mem_release_by_name() to release a reserved memory region
> with a given name. This allows us to release reserved memory which is
> defined by kernel cmdline, after boot.
>
> Signed-off-by: Masami Hiramatsu (Google) <mhira...@kernel.org>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Cc: Mike Rapoport <r...@kernel.org>
> Cc: linux...@kvack.org
...
> +/**
> + * reserve_mem_release_by_name - Release reserved memory region with a given
> name
> + * @name: The name that is attatched to a reserved memory region
> + *
> + * Forcibly release the pages in the reserved memory region so that those
> memory
> + * can be used as free memory. After released the reserved region size
> becomes 0.
> + *
> + * Returns: 1 if released or 0 if not found.
> + */
> +int reserve_mem_release_by_name(const char *name)
> +{
> + struct reserve_mem_table *map;
> + unsigned int page_count;
> + phys_addr_t start;
> +
> + guard(mutex)(&reserve_mem_lock);
> + map = reserve_mem_find_by_name_nolock(name);
> + if (!map)
> + return 0;
> +
> + start = map->start;
> + page_count = DIV_ROUND_UP(map->size, PAGE_SIZE);
> +
> + for (int i = 0; i < page_count; i++) {
> + phys_addr_t addr = start + i * PAGE_SIZE;
> + struct page *page = pfn_to_page(addr >> PAGE_SHIFT);
> +
> + page->flags &= ~BIT(PG_reserved);
> + __free_page(page);
> + }
We have free_reserved_area(), please use it here.
Otherwise
Acked-by: Mike Rapoport (Microsoft) <r...@kernel.org>
> + map->size = 0;
> +
> + return 1;
> +}
> +
> /*
> * Parse reserve_mem=nn:align:name
> */
>
--
Sincerely yours,
Mike.
