Re: [PATCH 6/7] lib/random32.c: Randomize timeout to the millisecond, not the second

George Spelvin
2014-06-08T11:30:04Z

> Fine by me this cleanup, although not strictly needed.

Agreed. The timer slack is set to HZ (1 second) anyway.

It just dawned on me that a simpler and more efficient way to do this
(which I'll do in v2 of this) would be:

/* reseed every ~60 seconds, in [40 .. 80) interval with slack */
- expires = 40 + (prandom_u32() % 40);
- seed_timer.expires = jiffies + msecs_to_jiffies(expires * MSEC_PER_SEC);
+ expires = 40*HZ + prandom_u32_max(40*HZ);
+ seed_timer.expires = jiffies + expires;

That avoids calling msecs_to_jiffies entirely.