Re: [PATCH] printk: Add printk_flush() to force buffered text to console

[Fengguang Wu <fengguang.wu@intel.com>]

> - printing one full line, and suppress the later OK entirely. The OK
>   might not be needed at all; we will find out that the machine
>   has not crashed at that point and a message in case of an error
>   could be sufficient in most cases.

That looks neat and feasible.  We not only get less output, but also
eliminate the problem of flushing:

        [   16.309109] Testing tracer irqsoff: PASSED
        [   17.184240] Testing tracer wakeup: PASSED
        [   18.060218] Testing tracer wakeup_rt: PASSED
        [   18.729222] Testing tracer function_graph: PASSED
        ...thousands more lines
=>
        [   16.309109] Testing tracer irqsoff
        [   17.184240] Testing tracer wakeup
        [   18.060218] Testing tracer wakeup_rt
        [   18.729222] Testing tracer function_graph
        ...thousands more lines

However these two special lines will have to be broken up into more lines:

        [   14.947553] Testing dynamic ftrace ops #1: (1 0 1 1 0) (1 1 2 1 0) (2 1 3 1 26) (2 2 4 1 43) PASSED
        [   15.740993] Testing dynamic ftrace ops #2: (1 0 1 26 0) (1 1 2 43 0) (2 1 3 1 15) (2 2 4 18 32) PASSED

Thanks,
Fengguang