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? > 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 ..." > Changes in v2: > Use cpus_read_lock() instead of copying cpu_online_mask at the entry of > function > To resolve kernel test robot warnings ([1] and [2])? Or have they been fixed? [1]: https://lore.kernel.org/stable/202304081615.eiaqpbV8-lkp@xxxxxxxxx/ [2]: https://lore.kernel.org/stable/202304082051.Dp50upfS-lkp@xxxxxxxxx/ Thanks. -- An old man doll... just what I always wanted! - Clara