ARRAY_SIZE(nf_conntrack_locks) is undefined if spinlock_t is an
empty structure. Replace it by CONNTRACK_LOCKS
Fixes: 93bb0ceb75 ("netfilter: conntrack: remove central spinlock nf_conntrack_lock")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexander Aring says:
====================
at86rf230: various fixes and devicetree support
this patch series fix some bugs with the at86rf231 chip and cleaup some code.
Also add devicetree support for the at86rf230 driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds devicetree support for the at86rf230 driver.
Possible gpios to configure are "reset-gpio" and "sleep-gpio".
Also add support to configure the "irq-type" for the irq polarity
register.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch make the reset pin optionally. Some devices like the atben
from qi-hardware don't have a reset pin externally. The usually way is
to turn power off/on for the atben device to initiate a device reset.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While checkpatch another patch I got a:
"WARNING: msleep < 20ms can sleep for up to 20ms"
The datasheet of at86rf231 and at86rf212 says a minimum delay for reset
pulse width and spi access latency after reset is 625 nanoseconds.
This patch removes the 1 milliseconds sleep and replace it with a 1
microseconds udelay which should be also okay for the reset pulse width.
To change the state from RESET -> TRX_OFF the at86rf230 device needs 120
microseconds, this is a worst case of all at86rf* chips.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no need to lock the clearing of IRQ_TRX_END in status.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fix a unexpected state change for the at86rf231 chip.
We can't change into STATE_FORCE_TX_ON while the chip is in one of
SLEEP, P_ON, RESET, TRX_OFF, and all *_NOCLK states.
In this case we are in the TRX_OFF state. See datasheet [1] page 71 for
more information.
Without this patch you will get the following message on a at86rf231 device:
[ 20.065218] unexpected state change: 8, asked for 4
[ 20.070527] ------------[ cut here ]------------
[ 20.075414] WARNING: CPU: 0 PID: 160 at net/mac802154/ieee802154_dev.c:43 mac802154_slave_open+0x70/0xb8()
[ 20.085594] Modules linked in: autofs4
[ 20.089667] CPU: 0 PID: 160 Comm: ifconfig Not tainted 3.14.0-20140108-1-00993-g905c192 #162
[ 20.098612] [<c00127b8>] (unwind_backtrace) from [<c0010b1c>] (show_stack+0x10/0x14)
[ 20.106819] [<c0010b1c>] (show_stack) from [<c0033838>] (warn_slowpath_common+0x60/0x80)
[ 20.115311] [<c0033838>] (warn_slowpath_common) from [<c00338e8>] (warn_slowpath_null+0x18/0x20)
[ 20.124590] [<c00338e8>] (warn_slowpath_null) from [<c057b7e8>] (mac802154_slave_open+0x70/0xb8)
[ 20.133880] [<c057b7e8>] (mac802154_slave_open) from [<c0488a58>] (__dev_open+0xa8/0x108)
[ 20.142553] [<c0488a58>] (__dev_open) from [<c0488cb0>] (__dev_change_flags+0x8c/0x148)
[ 20.151051] [<c0488cb0>] (__dev_change_flags) from [<c0488d84>] (dev_change_flags+0x18/0x48)
[ 20.159968] [<c0488d84>] (dev_change_flags) from [<c04e2e9c>] (devinet_ioctl+0x2b0/0x63c)
[ 20.168623] [<c04e2e9c>] (devinet_ioctl) from [<c04712e4>] (sock_ioctl+0x23c/0x29c)
[ 20.176727] [<c04712e4>] (sock_ioctl) from [<c00e3cb8>] (do_vfs_ioctl+0x4a8/0x578)
[ 20.184671] [<c00e3cb8>] (do_vfs_ioctl) from [<c00e3dd4>] (SyS_ioctl+0x4c/0x78)
[ 20.192402] [<c00e3dd4>] (SyS_ioctl) from [<c000da00>] (ret_fast_syscall+0x0/0x48)
[ 20.200392] ---[ end trace 9a34542f4ea08e47 ]---
This patch was tested on at86rf231 and at86rf212.
[1] http://www.atmel.com/images/doc8111.pdf
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sergei Shtylyov says:
====================
Beautify 'sh_eth' driver's messages
This patchset converts te driver to using netdev_*() and netif_*() to print out
its messages whenever possible.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that we call netdev_*() under netif_msg_*() checks, we can fold these into
netif_*() macro invocations.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert dev_*(&ndev->dev, ...) to netdev_*(ndev, ...) calls since they are a bit
shorter and at the same time give more information on a device.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert pr_*() to netdev_*() calls as the latter provide info on a device.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Exit the driver's probe() method when the register layout is unknown as the
driver would cause kernel oops in this case anyway.
While at it, move the corresponding error message printout and convert it from
pr_err() to dev_err().
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric W. Biederman says:
====================
netpoll: Cleanup received packet processing
This is the long-winded, careful, and polite version of removing the netpoll
receive packet processing.
First I untangle the code in small steps. Then I modify the code to not
force reception and dropping of packets when we are transmiting a packet
with netpoll. Finally I move all of the packet reception under
CONFIG_NETPOLL_TRAP and delete CONFIG_NETPOLL_TRAP.
If someone wants to do a stable backport of these patches, it would
require backporting the first 18 patches that handle the budget == 0 in
the networking drivers, and the first 6 of these patches.
If anyone wants to resurrect netpoll packet reception someday it should
just be a matter of reverting the last patch.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The netpoll packet receive code only becomes active if the netpoll
rx_skb_hook is implemented, and there is not a single implementation
of the netpoll rx_skb_hook in the kernel.
All of the out of tree implementations I have found all call
netpoll_poll which was removed from the kernel in 2011, so this
change should not add any additional breakage.
There are problems with the netpoll packet receive code. __netpoll_rx
does not call dev_kfree_skb_irq or dev_kfree_skb_any in hard irq
context. netpoll_neigh_reply leaks every skb it receives. Reception
of packets does not work successfully on stacked devices (aka bonding,
team, bridge, and vlans).
Given that the netpoll packet receive code is buggy, there are no
out of tree users that will be merged soon, and the code has
not been used for in tree for a decade let's just remove it.
Reverting this commit can server as a starting point for anyone
who wants to resurrect netpoll packet reception support.
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make rx_skb_hook, and rx in struct netpoll depend on
CONFIG_NETPOLL_TRAP Make rx_lock, rx_np, and neigh_tx in struct
netpoll_info depend on CONFIG_NETPOLL_TRAP
Make the functions netpoll_rx_on, netpoll_rx, and netpoll_receive_skb
no-ops when CONFIG_NETPOLL_TRAP is not set.
Only build netpoll_neigh_reply, checksum_udp service_neigh_queue,
pkt_is_ns, and __netpoll_rx when CONFIG_NETPOLL_TRAP is defined.
Add helper functions netpoll_trap_setup, netpoll_trap_setup_info,
netpoll_trap_cleanup, and netpoll_trap_cleanup_info that initialize
and cleanup the struct netpoll and struct netpoll_info receive
specific fields when CONFIG_NETPOLL_TRAP is enabled and do nothing
otherwise.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the bond slave device neigh_tx handling into service_neigh_queue.
In connection with neigh_tx processing remove unnecessary tests of
a NULL netpoll_info. As the netpoll_poll_dev has already used
and thus verified the existince of the netpoll_info.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that we no longer need to receive packets to safely drain the
network drivers receive queue move netpoll_trap and netpoll_set_trap
under CONFIG_NETPOLL_TRAP
Making netpoll_trap and netpoll_set_trap noop inline functions
when CONFIG_NETPOLL_TRAP is not set.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change the strategy of netpoll from dropping all packets received
during netpoll_poll_dev to calling napi poll with a budget of 0
(to avoid processing drivers rx queue), and to ignore packets received
with netif_rx (those will safely be placed on the backlog queue).
All of the netpoll supporting drivers have been reviewed to ensure
either thay use netif_rx or that a budget of 0 is supported by their
napi poll routine and that a budget of 0 will not process the drivers
rx queues.
Not dropping packets makes NETPOLL_RX_DROP unnecesary so it is removed.
npinfo->rx_flags is removed as rx_flags with just the NETPOLL_RX_ENABLED
flag becomes just a redundant mirror of list_empty(&npinfo->rx_np).
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper netpoll_rx_processing that reports when netpoll has
receive side processing to perform.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is already a warning for this case in the normal netpoll path,
but put a copy here in case how netpoll calls the poll functions
causes a differenet result.
netpoll will shortly call the napi poll routine with a budget 0 to
avoid any rx packets being processed. As nothing does that today
we may encounter drivers that have problems so a netpoll specific
warning seems desirable.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In poll_napi loop through all of the napi handlers even when the
budget falls to 0 to ensure that we process all of the tx_queues, and
so that we continue to call into drivers when our initial budget is 0.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This moves the control logic to the top level in netpoll_poll_dev
instead of having it dispersed throughout netpoll_poll_dev,
poll_napi and poll_one_napi.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Today netpoll depends on setting NETPOLL_RX_DROP before networking
drivers receive packets in interrupt context so that the packets can
be dropped. Move this setting into netpoll_poll_dev from
poll_one_napi so that if ndo_poll_controller happens to receive
packets we will drop the packets on the floor instead of letting the
packets bounce through the networking stack and potentially cause problems.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for net-next,
most relevantly they are:
* cleanup to remove double semicolon from stephen hemminger.
* calm down sparse warning in xt_ipcomp, from Fan Du.
* nf_ct_labels support for nf_tables, from Florian Westphal.
* new macros to simplify rcu dereferences in the scope of nfnetlink
and nf_tables, from Patrick McHardy.
* Accept queue and drop (including reason for drop) to verdict
parsing in nf_tables, also from Patrick.
* Remove unused random seed initialization in nfnetlink_log, from
Florian Westphal.
* Allow to attach user-specific information to nf_tables rules, useful
to attach user comments to rule, from me.
* Return errors in ipset according to the manpage documentation, from
Jozsef Kadlecsik.
* Fix coccinelle warnings related to incorrect bool type usage for ipset,
from Fengguang Wu.
* Add hash:ip,mark set type to ipset, from Vytas Dauksa.
* Fix message for each spotted by ipset for each netns that is created,
from Ilia Mirkin.
* Add forceadd option to ipset, which evicts a random entry from the set
if it becomes full, from Josh Hunt.
* Minor IPVS cleanups and fixes from Andi Kleen and Tingwei Liu.
* Improve conntrack scalability by removing a central spinlock, original
work from Eric Dumazet. Jesper Dangaard Brouer took them over to address
remaining issues. Several patches to prepare this change come in first
place.
* Rework nft_hash to resolve bugs (leaking chain, missing rcu synchronization
on element removal, etc. from Patrick McHardy.
* Restore context in the rule deletion path, as we now release rule objects
synchronously, from Patrick McHardy. This gets back event notification for
anonymous sets.
* Fix NAT family validation in nft_nat, also from Patrick.
* Improve scalability of xt_connlimit by using an array of spinlocks and
by introducing a rb-tree of hashtables for faster lookup of accounted
objects per network. This patch was preceded by several patches and
refactorizations to accomodate this change including the use of kmem_cache,
from Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
With current match design every invocation of the connlimit_match
function means we have to perform (number_of_conntracks % 256) lookups
in the conntrack table [ to perform GC/delete stale entries ].
This is also the reason why ____nf_conntrack_find() in perf top has
> 20% cpu time per core.
This patch changes the storage to rbtree which cuts down the number of
ct objects that need testing.
When looking up a new tuple, we only test the connections of the host
objects we visit while searching for the wanted host/network (or
the leaf we need to insert at).
The slot count is reduced to 32. Increasing slot count doesn't
speed up things much because of rbtree nature.
before patch (50kpps rx, 10kpps tx):
+ 20.95% ksoftirqd/0 [nf_conntrack] [k] ____nf_conntrack_find
+ 20.50% ksoftirqd/1 [nf_conntrack] [k] ____nf_conntrack_find
+ 20.27% ksoftirqd/2 [nf_conntrack] [k] ____nf_conntrack_find
+ 5.76% ksoftirqd/1 [nf_conntrack] [k] hash_conntrack_raw
+ 5.39% ksoftirqd/2 [nf_conntrack] [k] hash_conntrack_raw
+ 5.35% ksoftirqd/0 [nf_conntrack] [k] hash_conntrack_raw
after (90kpps, 51kpps tx):
+ 17.24% swapper [nf_conntrack] [k] ____nf_conntrack_find
+ 6.60% ksoftirqd/2 [nf_conntrack] [k] ____nf_conntrack_find
+ 2.73% swapper [nf_conntrack] [k] hash_conntrack_raw
+ 2.36% swapper [xt_connlimit] [k] count_tree
Obvious disadvantages to previous version are the increase in code
complexity and the increased memory cost.
Partially based on Eric Dumazets fq scheduler.
Reviewed-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
currently returns 1 if they're the same. Make it work like mem/strcmp
so it can be used as rbtree search function.
Reviewed-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If CONFIG_REGULATOR is not set, devm_regulator_get() returns NULL,
so use IS_ERR_OR_NULL() macro for checks.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
My objective is to be able to totally discriminate CAN ports on multi-port
cards via udev so as to rename them to semantically interesting/unique names
for my system (e.g., "ecuCAN" and "auxCAN" instead of "can0" and "can1").
The following patch assigns the dev_id field to match the channel number on all
multi-channel devices. I can only test my two-port Peak PCI card, but it works
as expected: ATTRS{dev_id} now expresses the port number and my udev rules now
unambiguously pick out and rename my individual CAN ports.
Signed-off-by: Christopher R. Baker <cbaker@rec.ri.cmu.edu>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> [PEAK PCAN-USB pro and EMS PCMCIA]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
CAN interfaces only support MTU values of 16 (CAN 2.0) and 72 (CAN FD).
Setting the MTU to other values is pointless but it does not really hurt.
With the introduction of the CAN FD support in drivers/net/can a new
function to switch the MTU for CAN FD has been introduced.
This patch makes use of this can_change_mtu() function to check for correct
MTU settings also in legacy CAN (2.0) devices.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Eric W. Biederman says:
====================
Don't receive packets when the napi budget == 0
After reading through all 120 drivers supporting netpoll I have found 16
more that process at least received packet when the napi budget == 0.
Processing more packets than your budget has always been a bug but
we haven't cared before so it looks like these drivers slipped through,
and need fixes.
As netpoll will shortly be using a budget of 0 to get the tx queue
processing with the rx queue processing we now care.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Processing any incoming packets with a with a napi budget of 0
is incorrect driver behavior.
This matters as netpoll will shortly call drivers with a budget of 0
to avoid receive packet processing happening in hard irq context.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hariprasad Shenai says:
====================
Doorbell drop Avoidance Bug fix for iw_cxgb4
This patch series provides fixes for Chelsio T4/T5 adapters
related to DB Drop avoidance and other small fix related to keepalive on
iw-cxgb4.
The patches series is created against David Miller's 'net-next' tree.
And includes patches on cxgb4 and iw_cxgb4 driver.
We would like to request this patch series to get merged via David Miller's
'net-next' tree.
We have included all the maintainers of respective drivers. Kindly review the
change and let us know in case of any review comments.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The current logic suffers from a slow response time to disable user DB
usage, and also fails to avoid DB FIFO drops under heavy load. This commit
fixes these deficiencies and makes the avoidance logic more optimal.
This is done by more efficiently notifying the ULDs of potential DB
problems, and implements a smoother flow control algorithm in iw_cxgb4,
which is the ULD that puts the most load on the DB fifo.
Design:
cxgb4:
Direct ULD callback from the DB FULL/DROP interrupt handler. This allows
the ULD to stop doing user DB writes as quickly as possible.
While user DB usage is disabled, the LLD will accumulate DB write events
for its queues. Then once DB usage is reenabled, a single DB write is
done for each queue with its accumulated write count. This reduces the
load put on the DB fifo when reenabling.
iw_cxgb4:
Instead of marking each qp to indicate DB writes are disabled, we create
a device-global status page that each user process maps. This allows
iw_cxgb4 to only set this single bit to disable all DB writes for all
user QPs vs traversing the idr of all the active QPs. If the libcxgb4
doesn't support this, then we fall back to the old approach of marking
each QP. Thus we allow the new driver to work with an older libcxgb4.
When the LLD upcalls iw_cxgb4 indicating DB FULL, we disable all DB writes
via the status page and transition the DB state to STOPPED. As user
processes see that DB writes are disabled, they call into iw_cxgb4
to submit their DB write events. Since the DB state is in STOPPED,
the QP trying to write gets enqueued on a new DB "flow control" list.
As subsequent DB writes are submitted for this flow controlled QP, the
amount of writes are accumulated for each QP on the flow control list.
So all the user QPs that are actively ringing the DB get put on this
list and the number of writes they request are accumulated.
When the LLD upcalls iw_cxgb4 indicating DB EMPTY, which is in a workq
context, we change the DB state to FLOW_CONTROL, and begin resuming all
the QPs that are on the flow control list. This logic runs on until
the flow control list is empty or we exit FLOW_CONTROL mode (due to
a DB DROP upcall, for example). QPs are removed from this list, and
their accumulated DB write counts written to the DB FIFO. Sets of QPs,
called chunks in the code, are removed at one time. The chunk size is 64.
So 64 QPs are resumed at a time, and before the next chunk is resumed, the
logic waits (blocks) for the DB FIFO to drain. This prevents resuming to
quickly and overflowing the FIFO. Once the flow control list is empty,
the db state transitions back to NORMAL and user QPs are again allowed
to write directly to the user DB register.
The algorithm is designed such that if the DB write load is high enough,
then all the DB writes get submitted by the kernel using this flow
controlled approach to avoid DB drops. As the load lightens though, we
resume to normal DB writes directly by user applications.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on original work by Anand Priyadarshee <anandp@chelsio.com>.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet
David S. Miller
Alexander Aring
Sergei Shtylyov
Eric W. Biederman
Florian Westphal
Alexander Shiyan
Christopher R. Baker
Oliver Hartkopp
Steve Wise