Messages in this thread Patch in this message | | | From | Phil Sutter <> | Subject | [PATCH v2 4/4] rhashtable-test: allow to retry even if -ENOMEM was returned | Date | Fri, 20 Nov 2015 18:17:20 +0100 |
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This is rather a hack to expose the current issue with rhashtable to under high pressure sometimes return -ENOMEM even though system memory is not exhausted and a consecutive insert may succeed.
Signed-off-by: Phil Sutter <phil@nwl.cc> --- lib/test_rhashtable.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c index 6fa77b3..270bf72 100644 --- a/lib/test_rhashtable.c +++ b/lib/test_rhashtable.c @@ -52,6 +52,10 @@ static int tcount = 10; module_param(tcount, int, 0); MODULE_PARM_DESC(tcount, "Number of threads to spawn (default: 10)"); +static bool enomem_retry = false; +module_param(enomem_retry, bool, 0); +MODULE_PARM_DESC(enomem_retry, "Retry insert even if -ENOMEM was returned (default: off)"); + struct test_obj { int value; struct rhash_head node; @@ -79,14 +83,22 @@ static struct semaphore startup_sem = __SEMAPHORE_INITIALIZER(startup_sem, 0); static int insert_retry(struct rhashtable *ht, struct rhash_head *obj, const struct rhashtable_params params) { - int err, retries = -1; + int err, retries = -1, enomem_retries = 0; do { retries++; cond_resched(); err = rhashtable_insert_fast(ht, obj, params); + if (err == -ENOMEM && enomem_retry) { + enomem_retries++; + err = -EBUSY; + } } while (err == -EBUSY); + if (enomem_retries) + pr_info(" %u insertions retried after -ENOMEM\n", + enomem_retries); + return err ? : retries; } -- 2.1.2
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