From 44c6fea82b5fcb4ebe09d8f7552b32a91203fddb Mon Sep 17 00:00:00 2001 From: Navdeep Parhar Date: Mon, 3 Feb 2020 23:30:39 +0000 Subject: [PATCH] cxgbe(4): Do not use pack boundary > 512B unless it is explicitly requested. This is a tradeoff between PCIe efficiency during large packet rx and packing efficiency during small packet rx. MFC after: 1 week Sponsored by: Chelsio Communications --- sys/dev/cxgbe/t4_sge.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/sys/dev/cxgbe/t4_sge.c b/sys/dev/cxgbe/t4_sge.c index 3f0b837bd55..fff9f7b7797 100644 --- a/sys/dev/cxgbe/t4_sge.c +++ b/sys/dev/cxgbe/t4_sge.c @@ -589,6 +589,9 @@ t4_sge_extfree_refs(void) return (refs - rels); } +/* max 4096 */ +#define MAX_PACK_BOUNDARY 512 + static inline void setup_pad_and_pack_boundaries(struct adapter *sc) { @@ -635,7 +638,10 @@ setup_pad_and_pack_boundaries(struct adapter *sc) pack = fl_pack; if (fl_pack < 16 || fl_pack == 32 || fl_pack > 4096 || !powerof2(fl_pack)) { - pack = max(sc->params.pci.mps, CACHE_LINE_SIZE); + if (sc->params.pci.mps > MAX_PACK_BOUNDARY) + pack = MAX_PACK_BOUNDARY; + else + pack = max(sc->params.pci.mps, CACHE_LINE_SIZE); MPASS(powerof2(pack)); if (pack < 16) pack = 16;