From: Harald Freudenberger Date: Fri, 17 Nov 2017 15:32:22 +0000 (+0100) Subject: s390/zcrypt: Fix wrong comparison leading to strange load balancing X-Git-Tag: v4.14.17~104 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=82b90de5b111deaa09ec61594a6df84a426dceba;p=platform%2Fkernel%2Flinux-rpi.git s390/zcrypt: Fix wrong comparison leading to strange load balancing [ Upstream commit 0b0882672640ced4deeebf84da0b88b6389619c4 ] The function to decide if one zcrypt queue is better than another one compared two pointers instead of comparing the values where the pointers refer to. So within the same zcrypt card when load of each queue was equal just one queue was used. This effect only appears on relatively lite load, typically with one thread applications. This patch fixes the wrong comparison and now the counters show that requests are balanced equally over all available queues within the cards. There is no performance improvement coming with this fix. As long as the queue depth for an APQN queue is not touched, processing is not faster when requests are spread over queues within the same card hardware. So this fix only beautifies the lszcrypt counter printouts. Signed-off-by: Harald Freudenberger Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c index b5f4006..a9a56aa 100644 --- a/drivers/s390/crypto/zcrypt_api.c +++ b/drivers/s390/crypto/zcrypt_api.c @@ -218,8 +218,8 @@ static inline bool zcrypt_queue_compare(struct zcrypt_queue *zq, weight += atomic_read(&zq->load); pref_weight += atomic_read(&pref_zq->load); if (weight == pref_weight) - return &zq->queue->total_request_count > - &pref_zq->queue->total_request_count; + return zq->queue->total_request_count > + pref_zq->queue->total_request_count; return weight > pref_weight; }