Hi, This is v6 of a series to implement threaded console printing as well as some other minor pieces (such as proc and sysfs recognition of nbcon consoles). v5 is here [0]. For information about the motivation of the nbcon consoles, please read the cover letter of the original v1 [1]. This series provides the remaining pieces of the printk rework. All other components are either already mainline or are currently in linux-next. In particular this series does: - Implement dedicated printing threads per nbcon console. - Implement forced threading of legacy consoles for PREEMPT_RT. - Implement nbcon support for proc and sysfs console-related files. - Provide a new helper function nbcon_reacquire_nobuf() to allow nbcon console drivers to reacquire ownership. Note that this series does *not* provide an nbcon console driver. That will come in a follow-up series. Here are the changes since v5: - In nbcon_kthreads_wake(), skip !CON_NBCON consoles. - In console_flush_all(), also skip nbcon consoles if ft.nbcon_atomic == true and improve comments explaining why. - In legacy_kthread_should_wakeup(), also skip nbcon consoles if ft.nbcon_atomic == true and improve comments explaining why. John Ogness [0] https://lore.kernel.org/lkml/20240830152916.10136-1-john.ogness@xxxxxxxxxxxxx [1] https://lore.kernel.org/lkml/20230302195618.156940-1-john.ogness@xxxxxxxxxxxxx John Ogness (16): printk: nbcon: Add function for printers to reacquire ownership printk: Fail pr_flush() if before SYSTEM_SCHEDULING printk: Flush console on unregister_console() printk: nbcon: Add context to usable() and emit() printk: nbcon: Init @nbcon_seq to highest possible printk: nbcon: Relocate nbcon_atomic_emit_one() printk: nbcon: Use thread callback if in task context for legacy printk: nbcon: Rely on kthreads for normal operation printk: Provide helper for message prepending printk: nbcon: Show replay message on takeover proc: consoles: Add notation to c_start/c_stop proc: Add nbcon support for /proc/consoles tty: sysfs: Add nbcon support for 'active' printk: Implement legacy printer kthread for PREEMPT_RT printk: nbcon: Assign nice -20 for printing threads printk: Avoid false positive lockdep report for legacy printing Thomas Gleixner (1): printk: nbcon: Introduce printer kthreads drivers/tty/tty_io.c | 2 +- fs/proc/consoles.c | 7 +- include/linux/console.h | 48 +++ kernel/printk/internal.h | 82 ++++- kernel/printk/nbcon.c | 507 +++++++++++++++++++++++++----- kernel/printk/printk.c | 467 ++++++++++++++++++++++++--- kernel/printk/printk_ringbuffer.h | 2 + kernel/printk/printk_safe.c | 4 +- 8 files changed, 986 insertions(+), 133 deletions(-) base-commit: d33d5e683b0d3b4f5fc6a49ce17583f8ca663944 -- 2.39.2
