[Intel-wired-lan] [next PATCH S49 10/15] i40e: avoid looping to check whether we're in vlan mode
Bimmy Pujari
bimmy.pujari at intel.com
Thu Sep 29 17:11:30 UTC 2016
From: Jacob Keller <jacob.e.keller at intel.com>
We determine that a vsi is in vlan_mode whenever it has any filters
with a vlan other than -1 (I40E_VLAN_ALL). The previous method of doing
so was to perform a loop whenever we needed the check. However, we can
notice that only place where filters are added (i40e_add_filter) can
change the condition from false to true, and the only place we can
return to false is in i40e_vsi_sync_filters_subtask. Thus, we can remove
the loop and use a boolean directly.
Doing this avoids looping over filters repeatedly especially while we're
already inside a loop over all the filters. This should reduce the
latency of filter operations throughout the driver.
Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>
Change-ID: Iafde08df588da2a2ea666997d05e11fad8edc338
---
drivers/net/ethernet/intel/i40e/i40e.h | 1 +
drivers/net/ethernet/intel/i40e/i40e_main.c | 48 ++++++++++++++++++++++-------
2 files changed, 38 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index c5d7a04..1d9a6b9 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -517,6 +517,7 @@ struct i40e_vsi {
spinlock_t mac_filter_hash_lock;
/* Fixed size hash table with 2^8 buckets for MAC filters */
DECLARE_HASHTABLE(mac_filter_hash, 8);
+ bool has_vlan_filter;
/* VSI stats */
struct rtnl_link_stats64 net_stats;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 5ea761c..be46109 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -1198,19 +1198,31 @@ struct i40e_mac_filter *i40e_find_mac(struct i40e_vsi *vsi, const u8 *macaddr)
**/
bool i40e_is_vsi_in_vlan(struct i40e_vsi *vsi)
{
- struct i40e_mac_filter *f;
- struct hlist_node *h;
- int bkt;
+ /* If we have a PVID, always operate in VLAN mode */
+ if (vsi->info.pvid)
+ return true;
- /* Only -1 for all the filters denotes not in vlan mode
- * so we have to go through all the list in order to make sure
+ /* We need to operate in VLAN mode whenever we have any filters with
+ * a VLAN other than I40E_VLAN_ALL. We could check the table each
+ * time, incurring search cost repeatedly. However, we can notice two
+ * things:
+ *
+ * 1) the only place where we can gain a VLAN filter is in
+ * i40e_add_filter.
+ *
+ * 2) the only place where filters are actually removed is in
+ * i40e_vsi_sync_filters_subtask.
+ *
+ * Thus, we can simply use a boolean value, has_vlan_filters which we
+ * will set to true when we add a vlan filter in i40e_add_filter. Then
+ * we have to perform the full search after deleting filters in
+ * i40e_vsi_sync_filters_subtask, but we already have to search
+ * filters here and can perform the check at the same time. This
+ * results in avoiding embedding a loop for vlan mode inside another
+ * loop over all the filters, and should maintain correctness as noted
+ * above.
*/
- hash_for_each_safe(vsi->mac_filter_hash, bkt, h, f, hlist) {
- if (f->vlan >= 0 || vsi->info.pvid)
- return true;
- }
-
- return false;
+ return vsi->has_vlan_filter;
}
/**
@@ -1246,6 +1258,12 @@ struct i40e_mac_filter *i40e_add_filter(struct i40e_vsi *vsi,
if (!f)
return NULL;
+ /* Update the boolean indicating if we need to function in
+ * vlan mode.
+ */
+ if (vlan >= 0)
+ vsi->has_vlan_filter = true;
+
ether_addr_copy(f->macaddr, macaddr);
f->vlan = vlan;
/* If we're in overflow promisc mode, set the state directly
@@ -1979,6 +1997,14 @@ int i40e_sync_vsi_filters(struct i40e_vsi *vsi)
del_list = NULL;
}
+ /* After finishing notifying firmware of the deleted filters, update
+ * the cached value of vsi->has_vlan_filter. Note that we are safe to
+ * use just !!vlan_filters here because if we only have VLAN=0 (that
+ * is, non_vlan_filters) these will all be converted to VLAN=-1 in the
+ * logic above already so this value would still be correct.
+ */
+ vsi->has_vlan_filter = !!vlan_filters;
+
if (!hlist_empty(&tmp_add_list)) {
/* Do all the adds now. */
filter_list_len = hw->aq.asq_buf_size /
--
2.4.11
More information about the Intel-wired-lan
mailing list