diff options
| -rw-r--r-- | drivers/char/random.c | 19 |
1 files changed, 2 insertions, 17 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 7ae7ea65da68..6da3f250804c 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -282,10 +282,8 @@ #define LONGS(x) (((x) + sizeof(unsigned long) - 1)/sizeof(unsigned long)) /* - * To allow fractional bits to be tracked, the following fields contain - * this many fractional bits: - * - * entropy_count, trickle_thresh + * To allow fractional bits to be tracked, the entropy_count field is + * denominated in units of 1/8th bits. * * 2*(ENTROPY_SHIFT + log2(poolbits)) must <= 31, or the multiply in * credit_entropy_bits() needs to be 64 bits wide. @@ -314,14 +312,6 @@ static int random_write_wakeup_thresh = 128; static int random_min_urandom_seed = 60; /* - * When the input pool goes over trickle_thresh, start dropping most - * samples to avoid wasting CPU time and reduce lock contention. - */ -static const int trickle_thresh = (INPUT_POOL_WORDS * 28) << ENTROPY_SHIFT; - -static DEFINE_PER_CPU(int, trickle_count); - -/* * Originally, we used a primitive polynomial of degree .poolwords * over GF(2). The taps for various sizes are defined below. They * were chosen to be evenly spaced except for the last tap, which is 1 @@ -755,10 +745,6 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num) long delta, delta2, delta3; preempt_disable(); - /* if over the trickle threshold, use only 1 in 4096 samples */ - if (ENTROPY_BITS(&input_pool) > trickle_thresh && - ((__this_cpu_inc_return(trickle_count) - 1) & 0xfff)) - goto out; sample.jiffies = jiffies; sample.cycles = random_get_entropy(); @@ -800,7 +786,6 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num) credit_entropy_bits(&input_pool, min_t(int, fls(delta>>1), 11)); } -out: preempt_enable(); } |