netdev - [net-next-2.6 PATCH 09/18] igb: cap interrupts at 20K per queue when in itr mode 3

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100217110317.17723.7586.stgit@localhost.localdomain>
Date:	Wed, 17 Feb 2010 03:03:19 -0800
From:	Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To:	davem@...emloft.net
Cc:	netdev@...r.kernel.org, gospo@...hat.com,
	Nicholas Nunley <nicholasx.d.nunley@...el.com>,
	Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next-2.6 PATCH 09/18] igb: cap interrupts at 20K per queue when
	in itr mode 3

From: Nick Nunley <nicholasx.d.nunley@...el.com>

In order to maintain similar performance between MSI-X and
legacy/MSI interrupts, this patch reduces the number of interrupts
when receiving small packets to 20K when in interrupt throttle
rate mode 3.

Signed-off-by: Nicholas Nunley <nicholasx.d.nunley@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---

 drivers/net/igb/igb_main.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index eb48e1a..4ccc7fc 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -3260,6 +3260,10 @@ static void igb_update_ring_itr(struct igb_q_vector *q_vector)
 	else
 		new_val = avg_wire_size / 2;
 
+	/* when in itr mode 3 do not exceed 20K ints/sec */
+	if (adapter->rx_itr_setting == 3 && new_val < 196)
+		new_val = 196;
+
 set_itr_val:
 	if (new_val != q_vector->itr_val) {
 		q_vector->itr_val = new_val;

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html