Author: vmaffione
Date: Wed Aug 12 14:17:38 2020
New Revision: 364164
URL: https://svnweb.freebsd.org/changeset/base/364164
Log:
iflib: refactor netmap_fl_refill and fix off-by-one issue
First, fix the initialization of the fl->ifl_rxd_idxs array,
which was affected by an off-by-one bug.
Once there, refactor the function to use better names for
local variables, optimize the variable assignments, and
merge the bus_dmamap_sync() inner loop with the outer one.
PR: 248494
MFC after: 3 weeks
Modified:
head/sys/net/iflib.c
Modified: head/sys/net/iflib.c
==============================================================================
--- head/sys/net/iflib.c Wed Aug 12 12:11:44 2020 (r364163)
+++ head/sys/net/iflib.c Wed Aug 12 14:17:38 2020 (r364164)
@@ -838,39 +838,41 @@ netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring
struct if_rxd_update iru;
if_ctx_t ctx = rxq->ifr_ctx;
iflib_fl_t fl = &rxq->ifr_fl[0];
- uint32_t refill_pidx, nic_i;
+ uint32_t nic_i_first, nic_i;
+ int i;
#if IFLIB_DEBUG_COUNTERS
int rf_count = 0;
#endif
if (nm_i == head && __predict_true(!init))
- return 0;
+ return (0);
+
iru_init(&iru, rxq, 0 /* flid */);
map = fl->ifl_sds.ifsd_map;
- refill_pidx = netmap_idx_k2n(kring, nm_i);
+ nic_i = netmap_idx_k2n(kring, nm_i);
/*
* IMPORTANT: we must leave one free slot in the ring,
* so move head back by one unit
*/
head = nm_prev(head, lim);
- nic_i = UINT_MAX;
DBG_COUNTER_INC(fl_refills);
while (nm_i != head) {
#if IFLIB_DEBUG_COUNTERS
if (++rf_count == 9)
DBG_COUNTER_INC(fl_refills_large);
#endif
- for (int tmp_pidx = 0; tmp_pidx < IFLIB_MAX_RX_REFRESH && nm_i
!= head; tmp_pidx++) {
+ nic_i_first = nic_i;
+ for (i = 0; i < IFLIB_MAX_RX_REFRESH && nm_i != head; i++) {
struct netmap_slot *slot = &ring->slot[nm_i];
- void *addr = PNMB(na, slot,
&fl->ifl_bus_addrs[tmp_pidx]);
- uint32_t nic_i_dma = refill_pidx;
- nic_i = netmap_idx_k2n(kring, nm_i);
+ void *addr = PNMB(na, slot, &fl->ifl_bus_addrs[i]);
- MPASS(tmp_pidx < IFLIB_MAX_RX_REFRESH);
+ MPASS(i < IFLIB_MAX_RX_REFRESH);
if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
return netmap_ring_reinit(kring);
+ fl->ifl_rxd_idxs[i] = nic_i;
+
if (__predict_false(init)) {
netmap_load_map(na, fl->ifl_buf_tag,
map[nic_i], addr);
@@ -879,33 +881,25 @@ netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring
netmap_reload_map(na, fl->ifl_buf_tag,
map[nic_i], addr);
}
+ bus_dmamap_sync(fl->ifl_buf_tag, map[nic_i],
+ BUS_DMASYNC_PREREAD);
slot->flags &= ~NS_BUF_CHANGED;
nm_i = nm_next(nm_i, lim);
- fl->ifl_rxd_idxs[tmp_pidx] = nic_i = nm_next(nic_i,
lim);
- if (nm_i != head && tmp_pidx < IFLIB_MAX_RX_REFRESH-1)
- continue;
-
- iru.iru_pidx = refill_pidx;
- iru.iru_count = tmp_pidx+1;
- ctx->isc_rxd_refill(ctx->ifc_softc, &iru);
- refill_pidx = nic_i;
- for (int n = 0; n < iru.iru_count; n++) {
- bus_dmamap_sync(fl->ifl_buf_tag, map[nic_i_dma],
- BUS_DMASYNC_PREREAD);
- /* XXX - change this to not use the netmap
func*/
- nic_i_dma = nm_next(nic_i_dma, lim);
- }
+ nic_i = nm_next(nic_i, lim);
}
+
+ iru.iru_pidx = nic_i_first;
+ iru.iru_count = i;
+ ctx->isc_rxd_refill(ctx->ifc_softc, &iru);
}
kring->nr_hwcur = head;
bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
- if (__predict_true(nic_i != UINT_MAX)) {
- ctx->isc_rxd_flush(ctx->ifc_softc, rxq->ifr_id, fl->ifl_id,
nic_i);
- DBG_COUNTER_INC(rxd_flush);
- }
+ ctx->isc_rxd_flush(ctx->ifc_softc, rxq->ifr_id, fl->ifl_id, nic_i);
+ DBG_COUNTER_INC(rxd_flush);
+
return (0);
}
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
