Hi, On Fri, Oct 21, 2022 at 8:09 AM Petr Mladek <pmladek@xxxxxxxx> wrote: > > On Wed 2022-10-19 17:01:43, John Ogness wrote: > > Use srcu console list iteration for safe console list traversal. > > > > Note that configure_kgdboc() still requires the console_lock in > > order to ensure that no console is in its write() callback when > > its direct() callback is called. Add comments to clarify this. > > s/direct()/device()/ > > Do you know about such requirements or is it just > a conservative approach, please? > > I ask because the comment in the code says "may assume". > > > Anyway, this would deserve a comment why the SRCU list iteration is > needed even when console_lock() is needed as well. > > The reason is that further patches are going to synchronize > console_list manipulation with another lock and console_lock() > will be used only to serialize accessing con->write() callbacks. I had the same concern. I'll note that at the end of the series the documentation for console_lock() still says: * Acquires a lock which guarantees that the caller has * exclusive access to the console system. That seems to imply (at least to me) that if you're holding console_lock() there's no need to hold the SRCU lock. -Doug
