On Mon, Apr 20, 2020 at 09:41:43AM +0800, Huang, Ying wrote:
>Wei Yang <richard.weiyang@xxxxxxxxx> writes:
>
>> Each time it needs jump to new_cluster, it is sure current
>> percpu_cluster is null.
>>
>> Move the new_cluster to check free_clusters directly.
>>
>> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
>> ---
>> mm/swapfile.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/mm/swapfile.c b/mm/swapfile.c
>> index 07b0bc095411..78e92ff14c79 100644
>> --- a/mm/swapfile.c
>> +++ b/mm/swapfile.c
>> @@ -603,9 +603,9 @@ static bool scan_swap_map_try_ssd_cluster(struct swap_info_struct *si,
>> struct swap_cluster_info *ci;
>> unsigned long tmp, max;
>>
>> -new_cluster:
>> cluster = this_cpu_ptr(si->percpu_cluster);
>> if (cluster_is_null(&cluster->index)) {
>> +new_cluster:
>> if (!cluster_list_empty(&si->free_clusters)) {
>> cluster->index = si->free_clusters.head;
>> cluster->next = cluster_next(&cluster->index) *
>
>In swap_do_scheduled_discard(), we will unlock si->lock, so the
>percpu_cluster may be changed after we releasing the lock. Or the
>current thread may be moved to a different CPU.
Thanks, you are right.
>
>Best Regards,
>Huang, Ying
--
Wei Yang
Help you, Help me
