DPDK patches and discussions
 help / color / mirror / Atom feed
From: Bruce Richardson <bruce.richardson@intel.com>
To: dev@dpdk.org
Subject: [dpdk-dev] [PATCH v2 3/5] testpmd: Change rxfreet default to 32
Date: Tue, 23 Sep 2014 12:08:15 +0100	[thread overview]
Message-ID: <1411470497-10209-4-git-send-email-bruce.richardson@intel.com> (raw)
In-Reply-To: <1411470497-10209-1-git-send-email-bruce.richardson@intel.com>

To improve performance by using bulk alloc or vectored RX routines, we
need to set rx free threshold (rxfreet) value to 32, so make this the
testpmd default.

Thirty-two is the minimum setting needed to enable either the
bulk alloc or vector RX routines inside the ixgbe driver, so it's
best made the default for that reason. Please see
"check_rx_burst_bulk_alloc_preconditions()" in ixgbe_rxtx.c, and
RX function assignment logic in "ixgbe_dev_rx_queue_setup()" in
the same file.

The difference in IO performance for testpmd when called without any
optional parameters, and using 10G NICs using the ixgbe driver, can be
significant - approx 25% or more.

Updates in V2:
* Updated commit message with additional details

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 app/test-pmd/testpmd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 9f6cdc4..f76406f 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -225,7 +225,9 @@ struct rte_eth_thresh tx_thresh = {
 /*
  * Configurable value of RX free threshold.
  */
-uint16_t rx_free_thresh = 0; /* Immediately free RX descriptors by default. */
+uint16_t rx_free_thresh = 32; /* Refill RX descriptors once every 32 packets,
+		This setting is needed for ixgbe to enable bulk alloc or vector
+		receive functionality. */
 
 /*
  * Configurable value of RX drop enable.
-- 
1.9.3

  parent reply	other threads:[~2014-09-23 11:02 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-17 10:01 [dpdk-dev] [PATCH 0/5] Mbuf Structure Rework, part 3 Bruce Richardson
2014-09-17 10:01 ` [dpdk-dev] [PATCH 1/5] mbuf: ensure next pointer is set to null on free Bruce Richardson
2014-09-17 10:01 ` [dpdk-dev] [PATCH 2/5] ixgbe: add prefetch to improve slow-path tx perf Bruce Richardson
2014-09-17 15:21   ` Neil Horman
2014-09-17 15:35     ` Richardson, Bruce
2014-09-17 17:59       ` Neil Horman
2014-09-18 13:36         ` Bruce Richardson
2014-09-18 15:29           ` Neil Horman
2014-09-18 15:42             ` Bruce Richardson
2014-09-18 17:56               ` Neil Horman
2014-09-17 10:01 ` [dpdk-dev] [PATCH 3/5] testpmd: Change rxfreet default to 32 Bruce Richardson
2014-09-17 15:29   ` Neil Horman
2014-09-18 15:53     ` Richardson, Bruce
2014-09-18 17:13       ` Thomas Monjalon
2014-09-18 18:08         ` Neil Horman
2014-09-19  9:18           ` Richardson, Bruce
2014-09-19 10:24             ` Neil Horman
2014-09-19 10:28               ` Richardson, Bruce
2014-09-19 15:18                 ` Neil Horman
2014-09-18 18:03       ` Neil Horman
2014-09-17 10:01 ` [dpdk-dev] [PATCH 4/5] mbuf: add userdata pointer field Bruce Richardson
2014-09-17 15:35   ` Neil Horman
2014-09-17 16:02     ` Richardson, Bruce
2014-09-17 18:29       ` Neil Horman
2014-09-17 10:01 ` [dpdk-dev] [PATCH 5/5] mbuf: Add in second vlan tag field to mbuf Bruce Richardson
2014-09-17 20:46   ` Stephen Hemminger
2014-09-23 11:08 ` [dpdk-dev] [PATCH v2 0/5] Mbuf Structure Rework, part 3 Bruce Richardson
2014-09-23 11:08   ` [dpdk-dev] [PATCH v2 1/5] mbuf: ensure next pointer is set to null on free Bruce Richardson
2014-09-23 11:08   ` [dpdk-dev] [PATCH v2 2/5] ixgbe: add prefetch to improve slow-path tx perf Bruce Richardson
2014-09-23 11:08   ` Bruce Richardson [this message]
2014-09-23 17:02     ` [dpdk-dev] [PATCH v2 3/5] testpmd: Change rxfreet default to 32 Neil Horman
2014-09-24  9:03       ` Richardson, Bruce
2014-09-24 10:05         ` Neil Horman
2014-11-07 12:30         ` Thomas Monjalon
2014-11-07 13:49           ` Bruce Richardson
2014-09-23 11:08   ` [dpdk-dev] [PATCH v2 4/5] mbuf: add userdata pointer field Bruce Richardson
2014-09-23 11:08   ` [dpdk-dev] [PATCH v2 5/5] mbuf: switch vlan_tci and reserved2 fields Bruce Richardson
2014-09-29 15:58   ` [dpdk-dev] [PATCH v2 0/5] Mbuf Structure Rework, part 3 De Lara Guarch, Pablo
2014-10-08 12:31     ` Thomas Monjalon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1411470497-10209-4-git-send-email-bruce.richardson@intel.com \
    --to=bruce.richardson@intel.com \
    --cc=dev@dpdk.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).