From: Paul Menzel [mailto:pmenzel@molgen.mpg.de] Sent: Wednesday, April 21, 2021 8:54 AM
[CC: Remove Jeff, as email is rejected]
Yes, thanks for the reminder. I had noticed it earlier.
[...]
diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c
b/drivers/net/ethernet/intel/ice/ice_lib.c
index d13c7fc8fb0a..d77133d6baa7 100644 --- a/drivers/net/ethernet/intel/ice/ice_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_lib.c @@ -161,12 +161,13 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi,
u16 vf_id)
switch (vsi->type) { case ICE_VSI_PF:
vsi->alloc_txq = min3(pf->num_lan_msix,ice_get_avail_txq_count(pf),(u16)num_online_cpus()); if (vsi->req_txq) { vsi->alloc_txq = vsi->req_txq; vsi->num_txq = vsi->req_txq;
} else {vsi->alloc_txq = min3(pf->num_lan_msix,ice_get_avail_txq_count(pf),(u16)num_online_cpus()); }I am curious, did you check the compiler actually creates different code, or did it notice the inefficiency by itself and optimized it already?
I have not looked into that detail but irrespective of what compiler generates I would like to keep the code in a shape which is more efficient and more readable.
I do understand in certain cases we have to do tradeoff between efficiency and readability but I do not see that here.
I agree, as *efficiency* is mentioned several times, I assume it was tested. Thank you for the clarification.
I mentioned inefficient because below code gets executed unnecessarily.
/** * ice_get_avail_q_count - Get count of queues in use * @pf_qmap: bitmap to get queue use count from * @lock: pointer to a mutex that protects access to pf_qmap * @size: size of the bitmap */ static u16 ice_get_avail_q_count(unsigned long *pf_qmap, struct mutex *lock, u16 size) { unsigned long bit; u16 count = 0;
mutex_lock(lock); for_each_clear_bit(bit, pf_qmap, size) count++; mutex_unlock(lock);
return count; }
/** * ice_get_avail_txq_count - Get count of Tx queues in use * @pf: pointer to an ice_pf instance */ u16 ice_get_avail_txq_count(struct ice_pf *pf) { return ice_get_avail_q_count(pf->avail_txqs, &pf->avail_q_mutex, pf->max_pf_txqs); }
pf->num_lan_tx = vsi->alloc_txq;@@ -175,12 +176,13 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi,
u16 vf_id)
if (!test_bit(ICE_FLAG_RSS_ENA, pf->flags)) { vsi->alloc_rxq = 1; } else {
vsi->alloc_rxq = min3(pf->num_lan_msix,ice_get_avail_rxq_count(pf),(u16)num_online_cpus()); if (vsi->req_rxq) { vsi->alloc_rxq = vsi->req_rxq; vsi->num_rxq = vsi->req_rxq;
} else {vsi->alloc_rxq = min3(pf->num_lan_msix,ice_get_avail_rxq_count(pf),(u16)num_online_cpus()); } }Kind regards,
Paul