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| author | Peng Liu <liupeng256@huawei.com> | 2022-03-22 14:48:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-22 15:57:11 -0700 |
| commit | 3cb1c9620eeeb67c614c0732a35861b0b1efdc53 (patch) | |
| tree | 97906f57afe9f27add8cd452bb19cbce27906f4d /mm/kfence | |
| parent | bdd015f7b71b92c2e4ecabac689642cc72553e04 (diff) | |
| download | linux-3cb1c9620eeeb67c614c0732a35861b0b1efdc53.tar.gz | |
kfence: test: try to avoid test_gfpzero trigger rcu_stall
When CONFIG_KFENCE_NUM_OBJECTS is set to a big number, kfence kunit-test-case test_gfpzero will eat up nearly all the CPU's resources and rcu_stall is reported as the following log which is cut from a physical server. rcu: INFO: rcu_sched self-detected stall on CPU rcu: 68-....: (14422 ticks this GP) idle=6ce/1/0x4000000000000002 softirq=592/592 fqs=7500 (t=15004 jiffies g=10677 q=20019) Task dump for CPU 68: task:kunit_try_catch state:R running task stack: 0 pid: 9728 ppid: 2 flags:0x0000020a Call trace: dump_backtrace+0x0/0x1e4 show_stack+0x20/0x2c sched_show_task+0x148/0x170 ... rcu_sched_clock_irq+0x70/0x180 update_process_times+0x68/0xb0 tick_sched_handle+0x38/0x74 ... gic_handle_irq+0x78/0x2c0 el1_irq+0xb8/0x140 kfree+0xd8/0x53c test_alloc+0x264/0x310 [kfence_test] test_gfpzero+0xf4/0x840 [kfence_test] kunit_try_run_case+0x48/0x20c kunit_generic_run_threadfn_adapter+0x28/0x34 kthread+0x108/0x13c ret_from_fork+0x10/0x18 To avoid rcu_stall and unacceptable latency, a schedule point is added to test_gfpzero. Link: https://lkml.kernel.org/r/20220309083753.1561921-4-liupeng256@huawei.com Signed-off-by: Peng Liu <liupeng256@huawei.com> Reviewed-by: Marco Elver <elver@google.com> Tested-by: Brendan Higgins <brendanhiggins@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Wang Kefeng <wangkefeng.wang@huawei.com> Cc: Daniel Latypov <dlatypov@google.com> Cc: David Gow <davidgow@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kfence')
| -rw-r--r-- | mm/kfence/kfence_test.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c index caed6b4eba94..1b50f70a4c0f 100644 --- a/mm/kfence/kfence_test.c +++ b/mm/kfence/kfence_test.c @@ -627,6 +627,7 @@ static void test_gfpzero(struct kunit *test) kunit_warn(test, "giving up ... cannot get same object back\n"); return; } + cond_resched(); } for (i = 0; i < size; i++) |