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torture: Add fuzzed hrtimer-based sleep functions

This commit adds torture_hrtimeout_ns(), torture_hrtimeout_us(), torture_hrtimeout_ms(), torture_hrtimeout_jiffies(), and torture_hrtimeout_s(), each of which uses hrtimers to block for a fuzzed time interval. These functions are intended to be used by the various torture tests to decouple wakeups from the timer wheel, thus providing more opportunity for Murphy to insert destructive race conditions.

Paul E. McKenney committed 5 years ago

Commit ae19aaa1 parent 682189a2 files · +82 −0Browse files

Unified · Split

2 files
  1. include/linux/torture.h +7 −0
  2. kernel/torture.c +75 −0
include/linux/torture.h+7−0
@@ -61,6 +61,13 @@ static inline void torture_random_init(struct torture_random_state *trsp) · 60 unmodified lines
6161 trsp->trs_count = 0;
6262 }
6363
64+/* Definitions for high-resolution-timer sleeps. */
65+int torture_hrtimeout_ns(ktime_t baset_ns, u32 fuzzt_ns, struct torture_random_state *trsp);
66+int torture_hrtimeout_us(u32 baset_us, u32 fuzzt_ns, struct torture_random_state *trsp);
67+int torture_hrtimeout_ms(u32 baset_ms, u32 fuzzt_us, struct torture_random_state *trsp);
68+int torture_hrtimeout_jiffies(u32 baset_j, struct torture_random_state *trsp);
69+int torture_hrtimeout_s(u32 baset_s, u32 fuzzt_ms, struct torture_random_state *trsp);
70+
6471 /* Task shuffler, which causes CPUs to occasionally go idle. */
6572 void torture_shuffle_task_register(struct task_struct *tp);
6673 int torture_shuffle_init(long shuffint);
kernel/torture.c+75−0
@@ -58,6 +58,81 @@ static int verbose; · 57 unmodified lines
5858 static int fullstop = FULLSTOP_RMMOD;
5959 static DEFINE_MUTEX(fullstop_mutex);
6060
61+/*
62+ * Schedule a high-resolution-timer sleep in nanoseconds, with a 32-bit
63+ * nanosecond random fuzz. This function and its friends desynchronize
64+ * testing from the timer wheel.
65+ */
66+int torture_hrtimeout_ns(ktime_t baset_ns, u32 fuzzt_ns, struct torture_random_state *trsp)
67+{
68+ ktime_t hto = baset_ns;
69+
70+ if (trsp)
71+ hto += (torture_random(trsp) >> 3) % fuzzt_ns;
72+ set_current_state(TASK_UNINTERRUPTIBLE);
73+ return schedule_hrtimeout(&hto, HRTIMER_MODE_REL);
74+}
75+EXPORT_SYMBOL_GPL(torture_hrtimeout_ns);
76+
77+/*
78+ * Schedule a high-resolution-timer sleep in microseconds, with a 32-bit
79+ * nanosecond (not microsecond!) random fuzz.
80+ */
81+int torture_hrtimeout_us(u32 baset_us, u32 fuzzt_ns, struct torture_random_state *trsp)
82+{
83+ ktime_t baset_ns = baset_us * NSEC_PER_USEC;
84+
85+ return torture_hrtimeout_ns(baset_ns, fuzzt_ns, trsp);
86+}
87+EXPORT_SYMBOL_GPL(torture_hrtimeout_us);
88+
89+/*
90+ * Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit
91+ * microsecond (not millisecond!) random fuzz.
92+ */
93+int torture_hrtimeout_ms(u32 baset_ms, u32 fuzzt_us, struct torture_random_state *trsp)
94+{
95+ ktime_t baset_ns = baset_ms * NSEC_PER_MSEC;
96+ u32 fuzzt_ns;
97+
98+ if ((u32)~0U / NSEC_PER_USEC < fuzzt_us)
99+ fuzzt_ns = (u32)~0U;
100+ else
101+ fuzzt_ns = fuzzt_us * NSEC_PER_USEC;
102+ return torture_hrtimeout_ns(baset_ns, fuzzt_ns, trsp);
103+}
104+EXPORT_SYMBOL_GPL(torture_hrtimeout_ms);
105+
106+/*
107+ * Schedule a high-resolution-timer sleep in jiffies, with an
108+ * implied one-jiffy random fuzz. This is intended to replace calls to
109+ * schedule_timeout_interruptible() and friends.
110+ */
111+int torture_hrtimeout_jiffies(u32 baset_j, struct torture_random_state *trsp)
112+{
113+ ktime_t baset_ns = jiffies_to_nsecs(baset_j);
114+
115+ return torture_hrtimeout_ns(baset_ns, jiffies_to_nsecs(1), trsp);
116+}
117+EXPORT_SYMBOL_GPL(torture_hrtimeout_jiffies);
118+
119+/*
120+ * Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit
121+ * millisecond (not second!) random fuzz.
122+ */
123+int torture_hrtimeout_s(u32 baset_s, u32 fuzzt_ms, struct torture_random_state *trsp)
124+{
125+ ktime_t baset_ns = baset_s * NSEC_PER_SEC;
126+ u32 fuzzt_ns;
127+
128+ if ((u32)~0U / NSEC_PER_MSEC < fuzzt_ms)
129+ fuzzt_ns = (u32)~0U;
130+ else
131+ fuzzt_ns = fuzzt_ms * NSEC_PER_MSEC;
132+ return torture_hrtimeout_ns(baset_ns, fuzzt_ns, trsp);
133+}
134+EXPORT_SYMBOL_GPL(torture_hrtimeout_s);
135+
61136 #ifdef CONFIG_HOTPLUG_CPU
62137
63138 /*

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