On Tue 2018-10-02 11:38:35, Sergey Senozhatsky wrote: > From: Sergey Senozhatsky <[email protected]> > > Prior to 5c2992ee7fd8a29 ("printk: remove console flushing special > cases for partial buffered lines") we would do console_cont_flush() > for each pr_cont() to print cont fragments, so console_unlock() would > actually print data: > > pr_cont(); > console_lock(); > console_unlock() > console_cont_flush(); // print cont fragment > ... > pr_cont(); > console_lock(); > console_unlock() > console_cont_flush(); // print cont fragment > > We don't do console_cont_flush() anymore, so when we do pr_cont() > console_unlock() does nothing (unless we flushed the cont buffer): > > pr_cont(); > console_lock(); > console_unlock(); // noop > ... > pr_cont(); > console_lock(); > console_unlock(); // noop > ... > pr_cont(); > cont_flush(); > console_lock(); > console_unlock(); // print data > > We also wakeup klogd purposelessly for pr_cont() output - un-flushed > cont buffer is not stored in log_buf; there is nothing to pull. > > Thus we can console_lock()/console_unlock()/wake_up_klogd() only when > we know that we log_store()-ed a message and there is something to > print to the consoles/syslog. > > Signed-off-by: Sergey Senozhatsky <[email protected]> > --- > kernel/printk/printk.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-)
The patch makes perfect sense. It looks a bit hacky but I can't think about any less hacky one. I wonder if it is worth it. But if nobody else is against it I am going to push it. I just hope that we will get rid of it with the buffered printk rather sooner than later. Best Regards, Petr
