Commit graph

27 commits

Author SHA1 Message Date
Eric Dumazet
ee8d153d46 net: annotate lockless accesses to sk->sk_napi_id
We already annotated most accesses to sk->sk_napi_id

We missed sk_mark_napi_id() and sk_mark_napi_id_once()
which might be called without socket lock held in UDP stack.

KCSAN reported :
BUG: KCSAN: data-race in udpv6_queue_rcv_one_skb / udpv6_queue_rcv_one_skb

write to 0xffff888121c6d108 of 4 bytes by interrupt on cpu 0:
 sk_mark_napi_id include/net/busy_poll.h:125 [inline]
 __udpv6_queue_rcv_skb net/ipv6/udp.c:571 [inline]
 udpv6_queue_rcv_one_skb+0x70c/0xb40 net/ipv6/udp.c:672
 udpv6_queue_rcv_skb+0xb5/0x400 net/ipv6/udp.c:689
 udp6_unicast_rcv_skb.isra.0+0xd7/0x180 net/ipv6/udp.c:832
 __udp6_lib_rcv+0x69c/0x1770 net/ipv6/udp.c:913
 udpv6_rcv+0x2b/0x40 net/ipv6/udp.c:1015
 ip6_protocol_deliver_rcu+0x22a/0xbe0 net/ipv6/ip6_input.c:409
 ip6_input_finish+0x30/0x50 net/ipv6/ip6_input.c:450
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip6_input+0x177/0x190 net/ipv6/ip6_input.c:459
 dst_input include/net/dst.h:442 [inline]
 ip6_rcv_finish+0x110/0x140 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ipv6_rcv+0x1a1/0x1b0 net/ipv6/ip6_input.c:284
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955
 napi_poll net/core/dev.c:6392 [inline]
 net_rx_action+0x3ae/0xa90 net/core/dev.c:6460

write to 0xffff888121c6d108 of 4 bytes by interrupt on cpu 1:
 sk_mark_napi_id include/net/busy_poll.h:125 [inline]
 __udpv6_queue_rcv_skb net/ipv6/udp.c:571 [inline]
 udpv6_queue_rcv_one_skb+0x70c/0xb40 net/ipv6/udp.c:672
 udpv6_queue_rcv_skb+0xb5/0x400 net/ipv6/udp.c:689
 udp6_unicast_rcv_skb.isra.0+0xd7/0x180 net/ipv6/udp.c:832
 __udp6_lib_rcv+0x69c/0x1770 net/ipv6/udp.c:913
 udpv6_rcv+0x2b/0x40 net/ipv6/udp.c:1015
 ip6_protocol_deliver_rcu+0x22a/0xbe0 net/ipv6/ip6_input.c:409
 ip6_input_finish+0x30/0x50 net/ipv6/ip6_input.c:450
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip6_input+0x177/0x190 net/ipv6/ip6_input.c:459
 dst_input include/net/dst.h:442 [inline]
 ip6_rcv_finish+0x110/0x140 net/ipv6/ip6_input.c:76
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ipv6_rcv+0x1a1/0x1b0 net/ipv6/ip6_input.c:284
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10890 Comm: syz-executor.0 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: e68b6e50fa ("udp: enable busy polling for all sockets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-30 17:34:35 -07:00
Thomas Gleixner
a61127c213 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 51 franklin st fifth floor boston ma 02110
  1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 111 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:06 +02:00
Christoph Hellwig
a331de3bf0 net: remove sock_poll_busy_flag
Fold it into the only caller to make the code simpler and easier to read.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-30 09:10:25 -07:00
Christoph Hellwig
f641f13b99 net: remove sock_poll_busy_loop
There is no point in hiding this logic in a helper.  Also remove the
useless events != 0 check and only busy loop once we know we actually
have a poll method.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-30 09:10:25 -07:00
Amritha Nambiar
c6345ce7d3 net: Record receive queue number for a connection
This patch adds a new field to sock_common 'skc_rx_queue_mapping'
which holds the receive queue number for the connection. The Rx queue
is marked in tcp_finish_connect() to allow a client app to do
SO_INCOMING_NAPI_ID after a connect() call to get the right queue
association for a socket. Rx queue is also marked in tcp_conn_request()
to allow syn-ack to go on the right tx-queue associated with
the queue on which syn is received.

Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-02 09:06:24 +09:00
Christoph Hellwig
3cafb37633 net: refactor socket_poll
Factor out two busy poll related helpers for late reuse, and remove
a command that isn't very helpful, especially with the __poll_t
annotations in place.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-26 09:16:44 +02:00
Daniel Borkmann
e4dde41273 net: fix compilation when busy poll is not enabled
MIN_NAPI_ID is used in various places outside of
CONFIG_NET_RX_BUSY_POLL wrapping, so when it's not set
we run into build errors such as:

  net/core/dev.c: In function 'dev_get_by_napi_id':
  net/core/dev.c:886:16: error: ‘MIN_NAPI_ID’ undeclared (first use in this function)
    if (napi_id < MIN_NAPI_ID)
                  ^~~~~~~~~~~

Thus, have MIN_NAPI_ID always defined to fix these errors.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-11 14:59:24 -07:00
Sridhar Samudrala
7db6b048da net: Commonize busy polling code to focus on napi_id instead of socket
Move the core functionality in sk_busy_loop() to napi_busy_loop() and
make it independent of sk.

This enables re-using this function in epoll busy loop implementation.

Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 20:49:31 -07:00
Alexander Duyck
37056719bb net: Track start of busy loop instead of when it should end
This patch flips the logic we were using to determine if the busy polling
has timed out.  The main motivation for this is that we will need to
support two different possible timeout values in the future and by
recording the start time rather than when we would want to end we can focus
on making the end_time specific to the task be it epoll or socket based
polling.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 20:49:31 -07:00
Alexander Duyck
2b5cd0dfa3 net: Change return type of sk_busy_loop from bool to void
checking the return value of sk_busy_loop. As there are only a few
consumers of that data, and the data being checked for can be replaced
with a check for !skb_queue_empty() we might as well just pull the code
out of sk_busy_loop and place it in the spots that actually need it.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 20:49:30 -07:00
Alexander Duyck
d2e64dbbe9 net: Only define skb_mark_napi_id in one spot instead of two
Instead of defining two versions of skb_mark_napi_id I think it is more
readable to just match the format of the sk_mark_napi_id functions and just
wrap the contents of the function instead of defining two versions of the
function.  This way we can save a few lines of code since we only need 2 of
the ifdef/endif but needed 5 for the extra function declaration.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 20:49:30 -07:00
Alexander Duyck
545cd5e5ec net: Busy polling should ignore sender CPUs
This patch is a cleanup/fix for NAPI IDs following the changes that made it
so that sender_cpu and napi_id were doing a better job of sharing the same
location in the sk_buff.

One issue I found is that we weren't validating the napi_id as being valid
before we started trying to setup the busy polling.  This change corrects
that by using the MIN_NAPI_ID value that is now used in both allocating the
NAPI IDs, as well as validating them.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 20:49:30 -07:00
Ingo Molnar
174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
Ingo Molnar
e601757102 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h>
We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.

Create a trivial placeholder <linux/sched/clock.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:27 +01:00
Eric Dumazet
37fabbf4d4 net: busy-poll: remove LL_FLUSH_FAILED and LL_FLUSH_BUSY
Commit 79e7fff47b ("net: remove support for per driver
ndo_busy_poll()") made them obsolete.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-13 22:23:39 -05:00
Eric Dumazet
e68b6e50fa udp: enable busy polling for all sockets
UDP busy polling is restricted to connected UDP sockets.

This is because sk_busy_loop() only takes care of one NAPI context.

There are cases where it could be extended.

1) Some hosts receive traffic on a single NIC, with one RX queue.

2) Some applications use SO_REUSEPORT and associated BPF filter
   to split the incoming traffic on one UDP socket per RX
queue/thread/cpu

3) Some UDP sockets are used to send/receive traffic for one flow, but
they do not bother with connect()

This patch records the napi_id of first received skb, giving more
reach to busy polling.

Tested:

lpaa23:~# echo 70 >/proc/sys/net/core/busy_read
lpaa24:~# echo 70 >/proc/sys/net/core/busy_read

lpaa23:~# for f in `seq 1 10`; do ./super_netperf 1 -H lpaa24 -t UDP_RR -l 5; done

Before patch :
   27867   28870   37324   41060   41215
   36764   36838   44455   41282   43843
After patch :
   73920   73213   70147   74845   71697
   68315   68028   75219   70082   73707

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18 10:44:31 -05:00
Eric Dumazet
21cb84c48c net: busy-poll: remove need_resched() from sk_can_busy_loop()
Now sk_busy_loop() can schedule by itself, we can remove
need_resched() check from sk_can_busy_loop()

Also add a const to its struct sock parameter.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Adam Belay <abelay@google.com>
Cc: Tariq Toukan <tariqt@mellanox.com>
Cc: Yuval Mintz <Yuval.Mintz@cavium.com>
Cc: Ariel Elior <ariel.elior@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-16 13:40:58 -05:00
Eric Dumazet
02d62e86fe net: un-inline sk_busy_loop()
There is really little gain from inlining this big function.
We'll soon make it even bigger in following patches.

This means we no longer need to export napi_by_id()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-18 16:17:38 -05:00
Peter Zijlstra
3708983452 sched, net: Fixup busy_loop_us_clock()
The only valid use of preempt_enable_no_resched() is if the very next
line is schedule() or if we know preemption cannot actually be enabled
by that statement due to known more preempt_count 'refs'.

This busy_poll stuff looks to be completely and utterly broken,
sched_clock() can return utter garbage with interrupts enabled (rare
but still) and it can drift unbounded between CPUs.

This means that if you get preempted/migrated and your new CPU is
years behind on the previous CPU we get to busy spin for a _very_ long
time.

There is a _REASON_ sched_clock() warns about preemptability -
papering over it with a preempt_disable()/preempt_enable_no_resched()
is just terminal brain damage on so many levels.

Replace sched_clock() usage with local_clock() which has a bounded
drift between CPUs (<2 jiffies).

There is a further problem with the entire busy wait poll thing in
that the spin time is additive to the syscall timeout, not inclusive.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: rui.zhang@intel.com
Cc: jacob.jun.pan@linux.intel.com
Cc: Mike Galbraith <bitbucket@online.de>
Cc: hpa@zytor.com
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: lenb@kernel.org
Cc: rjw@rjwysocki.net
Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131119151338.GF3694@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13 17:39:11 +01:00
Eliezer Tamir
3046e2f5b7 net: add cpu_relax to busy poll loop
Add a cpu_relaxt to sk_busy_loop.

Julie Cummings reported performance issues when hyperthreading is on.
Arjan van de Ven observed that we should have a cpu_relax() in the
busy poll loop.

Reported-by: Julie Cummings <julie.a.cummings@intel.com>
Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-28 17:45:48 -04:00
Eliezer Tamir
288a937637 net: rename busy poll MIB counter
Rename mib counter from "low latency" to "busy poll"

v1 also moved the counter to the ip MIB (suggested by Shawn Bohrer)
Eric Dumazet suggested that the current location is better.

So v2 just renames the counter to fit the new naming convention.

Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-09 11:39:08 -07:00
Eliezer Tamir
bf37d2b3fd busy_poll: cleanup do-nothing placeholders
When renaming ll_poll to busy poll, I introduced a typo
in the name of the do-nothing placeholder for sk_busy_loop
and called it sk_busy_poll.
This broke compile when busy poll was not configured.
Cong Wang submitted a patch to fixed that.
This patch removes the now redundant, misspelled placeholder.

Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-04 19:41:27 -07:00
Cong Wang
e0d1095ae3 net: rename CONFIG_NET_LL_RX_POLL to CONFIG_NET_RX_BUSY_POLL
Eliezer renames several *ll_poll to *busy_poll, but forgets
CONFIG_NET_LL_RX_POLL, so in case of confusion, rename it too.

Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-01 15:11:17 -07:00
Cong Wang
dfcefb0be1 net: fix a compile error when CONFIG_NET_LL_RX_POLL is not set
When CONFIG_NET_LL_RX_POLL is not set, I got:

net/socket.c: In function ‘sock_poll’:
net/socket.c:1165:4: error: implicit declaration of function ‘sk_busy_loop’ [-Werror=implicit-function-declaration]

Fix this by adding a nop when !CONFIG_NET_LL_RX_POLL.

Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-01 15:10:58 -07:00
Eliezer Tamir
64b0dc517e net: rename busy poll socket op and globals
Rename LL_SO to BUSY_POLL_SO
Rename sysctl_net_ll_{read,poll} to sysctl_busy_{read,poll}
Fix up users of these variables.
Fix documentation for sysctl.

a patch for the socket.7  man page will follow separately,
because of limitations of my mail setup.

Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-10 17:08:27 -07:00
Eliezer Tamir
8b80cda536 net: rename ll methods to busy-poll
Rename ndo_ll_poll to ndo_busy_poll.
Rename sk_mark_ll to sk_mark_napi_id.
Rename skb_mark_ll to skb_mark_napi_id.
Correct all useres of these functions.
Update comments and defines  in include/net/busy_poll.h

Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-10 17:08:27 -07:00
Eliezer Tamir
076bb0c82a net: rename include/net/ll_poll.h to include/net/busy_poll.h
Rename the file and correct all the places where it is included.

Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-10 17:08:27 -07:00
Renamed from include/net/ll_poll.h (Browse further)