Commit 5b237d65 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

locktorture: Mark statistics data races 



The lock_stress_stats structure's ->n_lock_fail and ->n_lock_acquired
fields are incremented and sampled locklessly using plain C-language
statements, which KCSAN objects to.  This commit therefore marks the
statistics gathering with data_race() to flag the intent.  While in
the area, this commit also reduces the number of accesses to the
->n_lock_acquired field, thus eliminating some possible check/use
confusion.

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 811192c5

kernel/locking/locktorture.c

+9 −7
Original line number Diff line number Diff line
@@ -738,20 +738,22 @@ static int lock_torture_reader(void *arg) 
static void __torture_print_stats(char *page,

				  struct lock_stress_stats *statp, bool write)

{

	long cur;

	bool fail = false;

	int i, n_stress;

	long max = 0, min = statp ? statp[0].n_lock_acquired : 0;

	long max = 0, min = statp ? data_race(statp[0].n_lock_acquired) : 0;

	long long sum = 0;



	n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress;

	for (i = 0; i < n_stress; i++) {

		if (statp[i].n_lock_fail)

		if (data_race(statp[i].n_lock_fail))

			fail = true;

		sum += statp[i].n_lock_acquired;

		if (max < statp[i].n_lock_acquired)

			max = statp[i].n_lock_acquired;

		if (min > statp[i].n_lock_acquired)

			min = statp[i].n_lock_acquired;

		cur = data_race(statp[i].n_lock_acquired);

		sum += cur;

		if (max < cur)

			max = cur;

		if (min > cur)

			min = cur;

	}

	page += sprintf(page,

			"%s:  Total: %lld  Max/Min: %ld/%ld %s  Fail: %d %s\n",