HI Dave,
On Fri, Dec 23, 2011 at 9:10 PM, Dave Hylands <[email protected]> wrote: > Hi Syam, > > On Thu, Dec 22, 2011 at 10:59 PM, Syam <[email protected]> wrote: > > HI All, > > > > I am getting more than 1 sec delay during booting. > > While registering console (for serial console ttys ), there is about 1 > sec > > delay in executing the console_unlock() in printk.c > > > > It was found that delay is occuring in call_console_drivers() > > ****************************** > > if (c == '\n') { > > if (msg_level < 0) { > > /* > > * printk() has already given us loglevel tags in > > * the buffer. This code is here in case the > > * log buffer has wrapped right round and scribbled > > * on those tags > > */ > > msg_level = default_message_loglevel; > > } > > _call_console_drivers(start_print, cur_index, msg_level); // if this > part > > is commented, there is no delay observed? > > ******************************* > > > > > > is there any way to find out what is causing the delay. > > The kernel actually starts logging the printk buffer before any > consoles are registered. When the first console is registered, it then > prints all of those messages which have been buffered until that time. > If you're logging your console messages to a serial port, then all of > those characters actually need to be sent out the UART, which is > probably where most of the time is being spent. > > -- > Dave Hylands > Shuswap, BC, Canada > http://www.davehylands.com > Thanks for the information. You are correct. I could see all the buffered messages are getting flushed during that part of execution. I guess, the only way to remove the delay is to remove the serial console logging by passing console=null. -- Warm Regards, Syam
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