Hi Bagas,
On Sun, 2023-04-09 at 19:30 +0700, Bagas Sanjaya wrote:
On 4/9/23 09:46, Tze-nan Wu wrote:
This issue can be reproduced by "echo 0 > trace" and hotplug cpu at the same time. After reproducing success, we can find out buffer_size_kb will not be functional anymore.
Do you mean disabling tracing while hotplugging CPU? Or disabling both tracing and hotplug CPU?
I mean disabling tracing while hotplugging CPU, sorry for the confusion here.
This patch uses cpus_read_lock() to prevent cpu_online_mask being changed between two different "for_each_online_buffer_cpu".
"Use cpu_read_lock() to prevent ..."
Thanks for the suggestion
Changes in v2: Use cpus_read_lock() instead of copying cpu_online_mask at the entry of function
Since I change to fix the issue by using cpus_read_lock(), we don't need a copy of cpu_online_mask anymore, hence the two warnings will not meet in the v2 patch.
To resolve kernel test robot warnings ([1] and [2])? Or have they been fixed?
Thanks.
-- An old man doll... just what I always wanted! - Clara