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| author | Boqun Feng <boqun.feng@gmail.com> | 2020-11-02 13:37:42 +0800 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-12-03 11:20:50 +0100 |
| commit | e04ce676e7aa490dcf5df880592e3db5e842a9bc (patch) | |
| tree | ff5ed969437455675e570795708e4e0357eab7c2 /lib/locking-selftest.c | |
| parent | a2e9ae58d5042b3aa4a61f676ff6975ff3bc7bc7 (diff) | |
| download | linux-e04ce676e7aa490dcf5df880592e3db5e842a9bc.tar.bz2 | |
lockdep/selftest: Add spin_nest_lock test
Add a self test case to test the behavior for the following case:
lock(A);
lock_nest_lock(C1, A);
lock(B);
lock_nest_lock(C2, A);
This is a reproducer for a problem[1] reported by Chris Wilson, and is
helpful to prevent this.
[1]: https://lore.kernel.org/lkml/160390684819.31966.12048967113267928793@build.alporthouse.com/
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201102053743.450459-2-boqun.feng@gmail.com
Diffstat (limited to 'lib/locking-selftest.c')
| -rw-r--r-- | lib/locking-selftest.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index afa7d4bb291f..4c24ac8a456c 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -2009,6 +2009,19 @@ static void ww_test_spin_nest_unlocked(void) U(A); } +/* This is not a deadlock, because we have X1 to serialize Y1 and Y2 */ +static void ww_test_spin_nest_lock(void) +{ + spin_lock(&lock_X1); + spin_lock_nest_lock(&lock_Y1, &lock_X1); + spin_lock(&lock_A); + spin_lock_nest_lock(&lock_Y2, &lock_X1); + spin_unlock(&lock_A); + spin_unlock(&lock_Y2); + spin_unlock(&lock_Y1); + spin_unlock(&lock_X1); +} + static void ww_test_unneeded_slow(void) { WWAI(&t); @@ -2226,6 +2239,10 @@ static void ww_tests(void) dotest(ww_test_spin_nest_unlocked, FAILURE, LOCKTYPE_WW); pr_cont("\n"); + print_testname("spinlock nest test"); + dotest(ww_test_spin_nest_lock, SUCCESS, LOCKTYPE_WW); + pr_cont("\n"); + printk(" -----------------------------------------------------\n"); printk(" |block | try |context|\n"); printk(" -----------------------------------------------------\n"); |