diff options
| author | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-10-05 16:43:09 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-12-01 12:45:41 -0800 |
| commit | 2e57bf97a6856f2dc10fb4377c452cb08f844047 (patch) | |
| tree | 3617b1482c7d9400708645b2729e87c65f995fa5 /kernel/rcu | |
| parent | 2667ccce9328e4e25ed77a83291c066d5e11e65a (diff) | |
| download | talos-obmc-linux-2e57bf97a6856f2dc10fb4377c452cb08f844047.tar.gz talos-obmc-linux-2e57bf97a6856f2dc10fb4377c452cb08f844047.zip | |
rcutorture: Use 100ms buckets for forward-progress callback histograms
This commit narrows the scope of each bucket of the forward-progress
callback-invocation histograms from one second to 100 milliseconds, which
aids debugging of forward-progress problems by making shorter-duration
callback-invocation stalls visible.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index afa98162575d..a4c4a24bdcaa 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1629,7 +1629,8 @@ static bool rcu_fwd_emergency_stop; #define MAX_FWD_CB_JIFFIES (8 * HZ) /* Maximum CB test duration. */ #define MIN_FWD_CB_LAUNDERS 3 /* This many CB invocations to count. */ #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ -static long n_launders_hist[2 * MAX_FWD_CB_JIFFIES / HZ]; +#define FWD_CBS_HIST_DIV 10 /* Histogram buckets/second. */ +static long n_launders_hist[2 * MAX_FWD_CB_JIFFIES / (HZ / FWD_CBS_HIST_DIV)]; static void rcu_torture_fwd_cb_hist(void) { @@ -1642,7 +1643,8 @@ static void rcu_torture_fwd_cb_hist(void) pr_alert("%s: Callback-invocation histogram (duration %lu jiffies):", __func__, jiffies - rcu_fwd_startat); for (j = 0; j <= i; j++) - pr_cont(" %ds: %ld", j + 1, n_launders_hist[j]); + pr_cont(" %ds/%d: %ld", + j + 1, FWD_CBS_HIST_DIV, n_launders_hist[j]); pr_cont("\n"); } @@ -1661,7 +1663,7 @@ static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) rcu_fwd_cb_tail = &rfcp->rfc_next; WRITE_ONCE(*rfcpp, rfcp); WRITE_ONCE(n_launders_cb, n_launders_cb + 1); - i = ((jiffies - rcu_fwd_startat) / HZ); + i = ((jiffies - rcu_fwd_startat) / (HZ / FWD_CBS_HIST_DIV)); if (i >= ARRAY_SIZE(n_launders_hist)) i = ARRAY_SIZE(n_launders_hist) - 1; n_launders_hist[i]++; |
