diff options
| author | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-10-03 12:33:41 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-12-01 12:45:39 -0800 |
| commit | 1a682754c7ed9df213069d5a0d3981f8360a32c2 (patch) | |
| tree | 8ca0ecd94efc87b01bcfca25e3430201176aeb32 /kernel/rcu/rcutorture.c | |
| parent | 8dd3b54689d9a2103c0817f2b7adc51760a45551 (diff) | |
rcutorture: Print histogram of CB invocation at OOM time
One reason why a forward-progress test might fail would be if something
prevented or delayed callback invocation. This commit therefore adds a
callback-invocation histogram printout when OOM is reported to rcutorture.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/rcu/rcutorture.c')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index f28b88ecb47a..329f4fb13125 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1631,6 +1631,20 @@ static bool rcu_fwd_emergency_stop; #define MIN_FWD_CBS_LAUNDERED 100 /* Number of counted CBs. */ static long n_launders_hist[2 * MAX_FWD_CB_JIFFIES / HZ]; +static void rcu_torture_fwd_cb_hist(void) +{ + int i; + int j; + + for (i = ARRAY_SIZE(n_launders_hist) - 1; i > 0; i--) + if (n_launders_hist[i] > 0) + break; + pr_alert("%s: Callback-invocation histogram:", __func__); + for (j = 0; j <= i; j++) + pr_cont(" %ds: %ld", j + 1, n_launders_hist[j]); + pr_cont("\n"); +} + /* Callback function for continuous-flood RCU callbacks. */ static void rcu_torture_fwd_cb_cr(struct rcu_head *rhp) { @@ -1718,7 +1732,6 @@ static void rcu_torture_fwd_prog_cr(void) unsigned long cver; unsigned long gps; int i; - int j; long n_launders; long n_launders_cb_snap; long n_launders_sa; @@ -1791,13 +1804,7 @@ static void rcu_torture_fwd_prog_cr(void) n_launders + n_max_cbs - n_launders_cb_snap, n_launders, n_launders_sa, n_max_gps, n_max_cbs, cver, gps); - for (i = ARRAY_SIZE(n_launders_hist) - 1; i > 0; i--) - if (n_launders_hist[i] > 0) - break; - pr_alert("Callback-invocation histogram:"); - for (j = 0; j <= i; j++) - pr_cont(" %ds: %ld", j + 1, n_launders_hist[j]); - pr_cont("\n"); + rcu_torture_fwd_cb_hist(); } } @@ -1809,6 +1816,7 @@ static void rcu_torture_fwd_prog_cr(void) static int rcutorture_oom_notify(struct notifier_block *self, unsigned long notused, void *nfreed) { + rcu_torture_fwd_cb_hist(); rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rcu_fwd_startat) / 2)); WRITE_ONCE(rcu_fwd_emergency_stop, true); return NOTIFY_OK; |