On 7/27/21 11:43 AM, Gavin Shan wrote:
> This uses struct pgtable_debug_args in the migration and thp test
> functions. It's notable that the pre-allocated page is used in
> swap_migration_tests() as set_pte_at() is used there.
>
> Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
> ---
> mm/debug_vm_pgtable.c | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index bc153cad9045..9136195efde3 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -845,7 +845,7 @@ static void __init pmd_swap_tests(struct pgtable_debug_args *args)
> static void __init pmd_swap_tests(struct pgtable_debug_args *args) { }
> #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
>
> -static void __init swap_migration_tests(void)
> +static void __init swap_migration_tests(struct pgtable_debug_args *args)
> {
> struct page *page;
> swp_entry_t swp;
> @@ -861,9 +861,10 @@ static void __init swap_migration_tests(void)
> * problematic. Lets allocate a dedicated page explicitly for this
> * purpose that will be freed subsequently.
> */
> - page = alloc_page(GFP_KERNEL);
> + page = (args->pte_pfn != ULONG_MAX) ?
> + pfn_to_page(args->pte_pfn) : NULL;
> if (!page) {
> - pr_err("page allocation failed\n");
> + pr_err("no page available\n");
> return;
> }
Please check for a valid page earlier in the function and return. Otherwise
this calls out the page unavailability (after starting the test), which is
inconsistent with all other functions like pxx_advanced_tests().
[ 1.051633] debug_vm_pgtable: [pte_swap_tests ]: Validating PTE swap
[ 1.052697] debug_vm_pgtable: [pmd_swap_tests ]: Validating PMD swap
[ 1.053765] debug_vm_pgtable: [swap_migration_tests ]: Validating swap migration <=====
[ 1.054900] debug_vm_pgtable: [swap_migration_tests ]: no page available <=====
Should do this just before pr_info("Validating swap migration\n").
......
page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
if (!page)
return;
.....
