Re: [PATCH] net/skbuff: silence warnings under memory pressure

On (09/05/19 13:14), Steven Rostedt wrote:

quoted

Hmm, from the article,

https://en.wikipedia.org/wiki/Universal_asynchronous_receiver-transmitter

"Since transmission of a single or multiple characters may take a long time
relative to CPU speeds, a UART maintains a flag showing busy status so that the
host system knows if there is at least one character in the transmit buffer or
shift register; "ready for next character(s)" may also be signaled with an
interrupt."

I'm pretty sure all serial consoles do a busy loop on the UART and not
use interrupts to notify when it's available.

Yes. Besides, we call console drivers with local IRQs disabled.

	-ss