Re: [PATCH 2/3] rhashtable-test: retry insert operations in threads
From: Thomas Graf <tgraf@suug.ch>
Date: 2015-08-28 11:09:33
Also in:
lkml, oe-lkp
On 08/28/15 at 12:28pm, Phil Sutter wrote:
quoted hunk ↗ jump to hunk
After adding cond_resched() calls to threadfunc(), a surprisingly high rate of insert failures occurred probably due to table resizes getting a better chance to run in background. To not soften up the remaining tests, retry inserts until they either succeed or fail permanently. Signed-off-by: Phil Sutter <phil@nwl.cc> --- lib/test_rhashtable.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c index 63654e3..093cf84 100644 --- a/lib/test_rhashtable.c +++ b/lib/test_rhashtable.c@@ -244,7 +244,7 @@ static int thread_lookup_test(struct thread_data *tdata) static int threadfunc(void *data) { - int i, step, err = 0, insert_fails = 0; + int i, step, err = 0, retries = 0; struct thread_data *tdata = data; up(&prestart_sem);@@ -253,21 +253,22 @@ static int threadfunc(void *data) for (i = 0; i < entries; i++) { tdata->objs[i].value = (tdata->id << 16) | i; +insert_retry: cond_resched(); err = rhashtable_insert_fast(&ht, &tdata->objs[i].node, test_rht_params); if (err == -ENOMEM || err == -EBUSY) { - tdata->objs[i].value = TEST_INSERT_FAIL; - insert_fails++; + retries++; + goto insert_retry;
Is it safe to retry indefinitely on ENOMEM? Retrying on EBUSY is definitely an improvement and we should do the same in the non threaded test as well.