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Raghu Vatsavayi ccdd0b4c35 liquidio: prevent rx queues from getting stalled
This commit has fix for RX traffic issues when we stress test the driver
with continuous ifconfig up/down under very high traffic conditions.

Reason for the issue is that, in existing liquidio_stop function NAPI is
disabled even before actual FW/HW interface is brought down via
send_rx_ctrl_cmd(lio, 0). Between time frame of NAPI disable and actual
interface down in firmware, firmware continuously enqueues rx traffic to
host. When interrupt happens for new packets, host irq handler fails in
scheduling NAPI as the NAPI is already disabled.

After "ifconfig <iface> up", Host re-enables NAPI but cannot schedule it
until it receives another Rx interrupt. Host never receives Rx interrupt as
it never cleared the Rx interrupt it received during interface down
operation. NIC Rx interrupt gets cleared only when Host processes queue and
clears the queue counts. Above anomaly leads to other issues like packet
overflow in FW/HW queues, backpressure.

Fix:
This commit fixes this issue by disabling NAPI only after informing
firmware to stop queueing packets to host via send_rx_ctrl_cmd(lio, 0).
send_rx_ctrl_cmd is not visible in the patch as it is already there in the
code. The DOWN command also waits for any pending packets to be processed
by NAPI so that the deadlock will not occur.

Signed-off-by: Raghu Vatsavayi <raghu.vatsavayi@cavium.com>
Acked-by: Derek Chickles <derek.chickles@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-30 14:16:19 -04:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-23 11:31:58 -04:00
block for-linus-20180302 2018-03-02 09:35:36 -08:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto X.509: fix NULL dereference when restricting key with unsupported_sig 2018-02-22 14:38:34 +00:00
Documentation dt-bindings: net: renesas-ravb: Add support for r8a77470 SoC 2018-03-30 12:32:48 -04:00
drivers liquidio: prevent rx queues from getting stalled 2018-03-30 14:16:19 -04:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs rxrpc, afs: Use debug_ids rather than pointers in traces 2018-03-27 23:03:00 +01:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2018-03-30 11:41:18 -04:00
init jump_label: Explicitly disable jump labels in __init code 2018-02-21 16:54:05 +01:00
ipc vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
kernel net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
lib test_bpf: Fix NULL vs IS_ERR() check in test_skb_segment() 2018-03-29 14:33:29 -04:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
mm mm, thp: do not cause memcg oom for thp 2018-03-22 17:07:02 -07:00
net ipv6: do not set routes if disable_ipv6 has been enabled 2018-03-30 12:20:52 -04:00
samples bpf: sockmap test script 2018-03-19 21:14:41 +01:00
scripts kbuild: Handle builtin dtb file names containing hyphens 2018-03-09 01:14:38 +09:00
security security: Remove rtnl_lock() in selinux_xfrm_notify_policyload() 2018-03-29 13:47:53 -04:00
sound ASoC: Fixes for v4.16 2018-03-12 17:30:38 +01:00
tools tc-testing: add connmark action tests 2018-03-30 12:58:23 -04:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt kvm/arm fixes for 4.16, take 2 2018-03-15 21:45:37 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore .gitignore: ignore ASN.1 auto generated files 2018-02-14 21:05:38 +01:00
.mailmap mailmap: update Mark Yao's email address 2018-01-04 16:45:09 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS MAINTAINERS: Update my email address from freescale to nxp 2018-03-30 12:57:13 -04:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-03-22 14:10:29 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.