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| author | Emilio G. Cota <cota@braap.org> | 2018-09-10 19:27:45 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-10-02 18:47:55 +0200 |
| commit | 39fe576c82bc02749410ea16045109f7b7d4af62 (patch) | |
| tree | 57f51b9625595796b130790deb9b3bc16610adfe /tests/test-rcu-list.c | |
| parent | ac8c77486cbdd5d7be17c447ca64cbebd330f25a (diff) | |
test-rcu-list: access n_reclaims and n_nodes_removed with atomic64
To avoid undefined behaviour.
Note that these "atomics" are atomic in the "access once" sense.
The variables are updated by a single thread at a time, so no
"full" atomics are necessary.
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20180910232752.31565-6-cota@braap.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'tests/test-rcu-list.c')
| -rw-r--r-- | tests/test-rcu-list.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/tests/test-rcu-list.c b/tests/test-rcu-list.c index 192bfbf02e..2e6f70bd59 100644 --- a/tests/test-rcu-list.c +++ b/tests/test-rcu-list.c @@ -33,8 +33,8 @@ static QemuMutex counts_mutex; static long long n_reads = 0LL; static long long n_updates = 0LL; -static long long n_reclaims = 0LL; -static long long n_nodes_removed = 0LL; +static int64_t n_reclaims; +static int64_t n_nodes_removed; static long long n_nodes = 0LL; static int g_test_in_charge = 0; @@ -104,7 +104,7 @@ static void reclaim_list_el(struct rcu_head *prcu) struct list_element *el = container_of(prcu, struct list_element, rcu); g_free(el); /* Accessed only from call_rcu thread. */ - n_reclaims++; + atomic_set_i64(&n_reclaims, n_reclaims + 1); } #if TEST_LIST_TYPE == 1 @@ -232,7 +232,7 @@ static void *rcu_q_updater(void *arg) qemu_mutex_lock(&counts_mutex); n_nodes += n_nodes_local; n_updates += n_updates_local; - n_nodes_removed += n_removed_local; + atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local); qemu_mutex_unlock(&counts_mutex); return NULL; } @@ -286,19 +286,21 @@ static void rcu_qtest(const char *test, int duration, int nreaders) n_removed_local++; } qemu_mutex_lock(&counts_mutex); - n_nodes_removed += n_removed_local; + atomic_set_i64(&n_nodes_removed, n_nodes_removed + n_removed_local); qemu_mutex_unlock(&counts_mutex); synchronize_rcu(); - while (n_nodes_removed > n_reclaims) { + while (atomic_read_i64(&n_nodes_removed) > atomic_read_i64(&n_reclaims)) { g_usleep(100); synchronize_rcu(); } if (g_test_in_charge) { - g_assert_cmpint(n_nodes_removed, ==, n_reclaims); + g_assert_cmpint(atomic_read_i64(&n_nodes_removed), ==, + atomic_read_i64(&n_reclaims)); } else { printf("%s: %d readers; 1 updater; nodes read: " \ - "%lld, nodes removed: %lld; nodes reclaimed: %lld\n", - test, nthreadsrunning - 1, n_reads, n_nodes_removed, n_reclaims); + "%lld, nodes removed: %"PRIi64"; nodes reclaimed: %"PRIi64"\n", + test, nthreadsrunning - 1, n_reads, + atomic_read_i64(&n_nodes_removed), atomic_read_i64(&n_reclaims)); exit(0); } } |