On 2020-04-13 12:18:17 [+0800], Liwei Song wrote:
> Interrupts are off during resume from RAM, this will triger a warning
> when allocate memory in non-preemptible context on RT since commit
> b5d5bc970f209 ("mm: Warn on memory allocation in non-preemptible
> context on RT"), exclude suspend from this warning check.
Is this the ACPI backtrace or do you have something else?
I'm currently not 100% sure if we can skip the warning.
> Fixes: b5d5bc970f209 ("mm: Warn on memory allocation in non-preemptible context on RT")
> Signed-off-by: Liwei Song <liwei.song@xxxxxxxxxxxxx>
> ---
> mm/slub.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index 1929645daa53..ebff24ae50ea 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -2771,7 +2771,8 @@ static __always_inline void *slab_alloc_node(struct kmem_cache *s,
> unsigned long tid;
>
> if (IS_ENABLED(CONFIG_PREEMPT_RT) && IS_ENABLED(CONFIG_DEBUG_ATOMIC_SLEEP))
> - WARN_ON_ONCE(!preemptible() && system_state >= SYSTEM_SCHEDULING);
> + WARN_ON_ONCE(!preemptible() && system_state >= SYSTEM_SCHEDULING &&
> + system_state != SYSTEM_SUSPEND);
>
> s = slab_pre_alloc_hook(s, gfpflags);
> if (!s)
> @@ -3236,7 +3237,8 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
> int i;
>
> if (IS_ENABLED(CONFIG_PREEMPT_RT) && IS_ENABLED(CONFIG_DEBUG_ATOMIC_SLEEP))
> - WARN_ON_ONCE(!preemptible() && system_state >= SYSTEM_SCHEDULING);
> + WARN_ON_ONCE(!preemptible() && system_state >= SYSTEM_SCHEDULING &&
> + system_state != SYSTEM_SUSPEND);
>
> /* memcg and kmem_cache debug support */
> s = slab_pre_alloc_hook(s, flags);
Sebastian
