On Thu, May 10, 2018 at 08:50:07PM +0100, Dmitry Safonov wrote:
> random uses __ratelimit() which calls ___ratelimit() with a function
> name. Depending on !RATELIMIT_MSG_ON_RELEASE it prints how many
> messages were suppressed every ratelimit interval (1 second for random)
> and flushes ratelimit_state::missed:
So the thing about the ratelimit system is that if you have a burst of
1,000,000 within the one second burst window, and then nothing ever
again, you will never see a message accounting for those 1,000,000
"callbacks" (which is a terrible wording; it just confuses people).
If you have a burst of 1,000,000 calls to ratelimit, and then a month
goes by, and *then* a single call to __ratelimit is called by printk,
only *the* does the message about the suppressed "callback" get
printed.
So in the case of the random driver, once the random driver is fully
intialized, there will never be a call to __ratelimit() for the
urandom ratelimit structures, so we manually print out the final
number of suppressed message so there is proper accounting for them.
It is not a double-count. If we didn't do that, those suppressed
warnings would never be mentioned by the kernel.
Cheers,
- Ted
