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@intel.com/ [2]: https://lore.kernel.org/stable/202304082051.Dp50upfS-lkp@intel.com/
Thanks.