Re: [PATCH 2/3] mm/sparse: Optimize sparse_add_one_section()

Mike Rapoport
2019-03-20T07:57:02Z

On Wed, Mar 20, 2019 at 03:35:39PM +0800, Baoquan He wrote:
> Reorder the allocation of usemap and memmap since usemap allocation
> is much smaller and simpler. Otherwise hard work is done to make
> memmap ready, then have to rollback just because of usemap allocation
> failure.
>
> Signed-off-by: Baoquan He <bhe@redhat.com>
> ---
> mm/sparse.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/mm/sparse.c b/mm/sparse.c
> index 0a0f82c5d969..054b99f74181 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -697,16 +697,17 @@ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn,
> ret = sparse_index_init(section_nr, nid);
> if (ret < 0 && ret != -EEXIST)
> return ret;
> - ret = 0;
> - memmap = kmalloc_section_memmap(section_nr, nid, altmap);
> - if (!memmap)
> - return -ENOMEM;
> +
> usemap = __kmalloc_section_usemap();
> - if (!usemap) {
> - __kfree_section_memmap(memmap, altmap);
> + if (!usemap)
> + return -ENOMEM;
> + memmap = kmalloc_section_memmap(section_nr, nid, altmap);
> + if (!memmap) {
> + kfree(usemap);

If you are anyway changing this why not to switch to goto's for error
handling?

> return -ENOMEM;
> }
>
> + ret = 0;
> ms = __pfn_to_section(start_pfn);
> if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
> ret = -EEXIST;
> --
> 2.17.2
>

--
Sincerely yours,
Mike.