Re: [PATCH V3] tracing/timerlat: Hotplug support for the user-space interface

[Steven Rostedt]

On Fri, 29 Sep 2023 17:02:46 +0200
Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> wrote:

> The osnoise/per_cpu/CPU$/timerlat_fd is create for each possible
> CPU, but it might create confusion if the CPU is not online.
> 
> Create the file only for online CPUs, also follow hotplug by
> creating and deleting as CPUs come and go.
> 
> Fixes: e88ed227f639 ("tracing/timerlat: Add user-space interface")

Is this a fix that needs to go in now and Cc'd to stable? Or is this
something that can wait till the next merge window?

-- Steve


> Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
> ---
> 
> Changes from V2:
>   - Better split the code into the generic (per_cpu/cpu$)
>     and timerlat (/timerlat_fd) specific function (Daniel)
>   - Fixed a cpus_read_lock/unlock() usage (kbuild test)
>   Link: https://lore.kernel.org/lkml/6b9a5f306e488bc77bf8521faeade420a0adf3e4.1695224204.git.bristot@xxxxxxxxxx/
> 
> Changes from V1:
>   - Fix compilation issue when !HOTPLUG
>   - Fix init interface | hotplug race
>   Link: https://lore.kernel.org/lkml/b619d9fd08a3bb47018cf40afa95783844a3c1fd.1694789910.git.bristot@xxxxxxxxxx/
> 
>  kernel/trace/trace_osnoise.c | 149 ++++++++++++++++++++++++++++-------
>  1 file changed, 121 insertions(+), 28 deletions(-)
> 
>