From f8619c300f49c5831d344d35df93d3af447efc97 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 6 Mar 2023 20:48:13 -0800 Subject: [PATCH] locktorture: Add long_hold to adjust lock-hold delays This commit adds a long_hold module parameter to allow testing diagnostics for excessive lock-hold times. Also adjust torture_param() invocations for longer line length while in the area. Signed-off-by: Paul E. McKenney Reviewed-by: Joel Fernandes (Google) --- kernel/locking/locktorture.c | 51 ++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 29 deletions(-) diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 153ddc4c47ef..949d3deae506 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -33,24 +33,19 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney "); -torture_param(int, nwriters_stress, -1, - "Number of write-locking stress-test threads"); -torture_param(int, nreaders_stress, -1, - "Number of read-locking stress-test threads"); +torture_param(int, nwriters_stress, -1, "Number of write-locking stress-test threads"); +torture_param(int, nreaders_stress, -1, "Number of read-locking stress-test threads"); +torture_param(int, long_hold, 100, "Do occasional long hold of lock (ms), 0=disable"); torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); -torture_param(int, onoff_interval, 0, - "Time between CPU hotplugs (s), 0=disable"); -torture_param(int, shuffle_interval, 3, - "Number of jiffies between shuffles, 0=disable"); +torture_param(int, onoff_interval, 0, "Time between CPU hotplugs (s), 0=disable"); +torture_param(int, shuffle_interval, 3, "Number of jiffies between shuffles, 0=disable"); torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable."); -torture_param(int, stat_interval, 60, - "Number of seconds between stats printk()s"); +torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s"); torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); torture_param(int, rt_boost, 2, - "Do periodic rt-boost. 0=Disable, 1=Only for rt_mutex, 2=For all lock types."); + "Do periodic rt-boost. 0=Disable, 1=Only for rt_mutex, 2=For all lock types."); torture_param(int, rt_boost_factor, 50, "A factor determining how often rt-boost happens."); -torture_param(int, verbose, 1, - "Enable verbose debugging printk()s"); +torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); torture_param(int, nested_locks, 0, "Number of nested locks (max = 8)"); /* Going much higher trips "BUG: MAX_LOCKDEP_CHAIN_HLOCKS too low!" errors */ #define MAX_NESTED_LOCKS 8 @@ -120,7 +115,7 @@ static int torture_lock_busted_write_lock(int tid __maybe_unused) static void torture_lock_busted_write_delay(struct torture_random_state *trsp) { - const unsigned long longdelay_ms = 100; + const unsigned long longdelay_ms = long_hold ? long_hold : ULONG_MAX; /* We want a long delay occasionally to force massive contention. */ if (!(torture_random(trsp) % @@ -198,16 +193,18 @@ __acquires(torture_spinlock) static void torture_spin_lock_write_delay(struct torture_random_state *trsp) { const unsigned long shortdelay_us = 2; - const unsigned long longdelay_ms = 100; + const unsigned long longdelay_ms = long_hold ? long_hold : ULONG_MAX; + unsigned long j; /* We want a short delay mostly to emulate likely code, and * we want a long delay occasionally to force massive contention. */ - if (!(torture_random(trsp) % - (cxt.nrealwriters_stress * 2000 * longdelay_ms))) + if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 2000 * longdelay_ms))) { + j = jiffies; mdelay(longdelay_ms); - if (!(torture_random(trsp) % - (cxt.nrealwriters_stress * 2 * shortdelay_us))) + pr_alert("%s: delay = %lu jiffies.\n", __func__, jiffies - j); + } + if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 200 * shortdelay_us))) udelay(shortdelay_us); if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) torture_preempt_schedule(); /* Allow test to be preempted. */ @@ -322,7 +319,7 @@ __acquires(torture_rwlock) static void torture_rwlock_write_delay(struct torture_random_state *trsp) { const unsigned long shortdelay_us = 2; - const unsigned long longdelay_ms = 100; + const unsigned long longdelay_ms = long_hold ? long_hold : ULONG_MAX; /* We want a short delay mostly to emulate likely code, and * we want a long delay occasionally to force massive contention. @@ -455,14 +452,12 @@ __acquires(torture_mutex) static void torture_mutex_delay(struct torture_random_state *trsp) { - const unsigned long longdelay_ms = 100; + const unsigned long longdelay_ms = long_hold ? long_hold : ULONG_MAX; /* We want a long delay occasionally to force massive contention. */ if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 2000 * longdelay_ms))) mdelay(longdelay_ms * 5); - else - mdelay(longdelay_ms / 5); if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) torture_preempt_schedule(); /* Allow test to be preempted. */ } @@ -630,7 +625,7 @@ __acquires(torture_rtmutex) static void torture_rtmutex_delay(struct torture_random_state *trsp) { const unsigned long shortdelay_us = 2; - const unsigned long longdelay_ms = 100; + const unsigned long longdelay_ms = long_hold ? long_hold : ULONG_MAX; /* * We want a short delay mostly to emulate likely code, and @@ -640,7 +635,7 @@ static void torture_rtmutex_delay(struct torture_random_state *trsp) (cxt.nrealwriters_stress * 2000 * longdelay_ms))) mdelay(longdelay_ms); if (!(torture_random(trsp) % - (cxt.nrealwriters_stress * 2 * shortdelay_us))) + (cxt.nrealwriters_stress * 200 * shortdelay_us))) udelay(shortdelay_us); if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) torture_preempt_schedule(); /* Allow test to be preempted. */ @@ -695,14 +690,12 @@ __acquires(torture_rwsem) static void torture_rwsem_write_delay(struct torture_random_state *trsp) { - const unsigned long longdelay_ms = 100; + const unsigned long longdelay_ms = long_hold ? long_hold : ULONG_MAX; /* We want a long delay occasionally to force massive contention. */ if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 2000 * longdelay_ms))) mdelay(longdelay_ms * 10); - else - mdelay(longdelay_ms / 10); if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) torture_preempt_schedule(); /* Allow test to be preempted. */ } @@ -848,8 +841,8 @@ static int lock_torture_writer(void *arg) lwsp->n_lock_acquired++; } - cxt.cur_ops->write_delay(&rand); if (!skip_main_lock) { + cxt.cur_ops->write_delay(&rand); lock_is_write_held = false; WRITE_ONCE(last_lock_release, jiffies); cxt.cur_ops->writeunlock(tid);