linux.git/net/core/sock.c, branch v4.3 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git net: core: drop null test before destroy functions 2015-09-15T23:49:43+00:00 Julia Lawall julia.lawall@lip6.fr 2015-09-13T12:15:18+00:00 adf78edac09f9640cd9676571586c4be46fb527c Remove unneeded NULL test. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x; @@ -if (x != NULL) { \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x); x = NULL; -} // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: David S. Miller <davem@davemloft.net> 
Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@ expression x; @@
-if (x != NULL) {
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
  x = NULL;
-}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
sock: fix kernel doc error 2015-08-28T00:12:41+00:00 Jean Sacren sakiwit@gmail.com 2015-08-28T00:05:49+00:00 69dba9bbc50609f19ee89d62d5199c81fcbc74b2 The symbol '__sk_reclaim' is not present in the current tree. Apparently '__sk_reclaim' was meant to be '__sk_mem_reclaim', so fix it with the right symbol name for the kernel doc. Signed-off-by: Jean Sacren <sakiwit@gmail.com> Cc: Hideo Aoki <haoki@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The symbol '__sk_reclaim' is not present in the current tree. Apparently
'__sk_reclaim' was meant to be '__sk_mem_reclaim', so fix it with the
right symbol name for the kernel doc.

Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Cc: Hideo Aoki <haoki@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket 2015-07-30T22:59:12+00:00 Sowmini Varadhan sowmini.varadhan@oracle.com 2015-07-30T13:50:36+00:00 8a68173691f036613e3d4e6bf8dc129d4a7bf383 The newsk returned by sk_clone_lock should hold a get_net() reference if, and only if, the parent is not a kernel socket (making this similar to sk_alloc()). E.g,. for the SYN_RECV path, tcp_v4_syn_recv_sock->..inet_csk_clone_lock sets up the syn_recv newsk from sk_clone_lock. When the parent (listen) socket is a kernel socket (defined in sk_alloc() as having sk_net_refcnt == 0), then the newsk should also have a 0 sk_net_refcnt and should not hold a get_net() reference. Fixes: 26abe14379f8 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.") Acked-by: Eric Dumazet <edumazet@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
The newsk returned by sk_clone_lock should hold a get_net()
reference if, and only if, the parent is not a kernel socket
(making this similar to sk_alloc()).

E.g,. for the SYN_RECV path, tcp_v4_syn_recv_sock->..inet_csk_clone_lock
sets up the syn_recv newsk from sk_clone_lock. When the parent (listen)
socket is a kernel socket (defined in sk_alloc() as having
sk_net_refcnt == 0), then the newsk should also have a 0 sk_net_refcnt
and should not hold a get_net() reference.

Fixes: 26abe14379f8 ("net: Modify sk_alloc to not reference count the
      netns of kernel sockets.")
Acked-by: Eric Dumazet <edumazet@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp: fix recv with flags MSG_WAITALL | MSG_PEEK 2015-07-27T08:06:53+00:00 Sabrina Dubroca sd@queasysnail.net 2015-07-24T16:19:25+00:00 dfbafc995304ebb9a9b03f65083e6e9cea143b20 Currently, tcp_recvmsg enters a busy loop in sk_wait_data if called with flags = MSG_WAITALL | MSG_PEEK. sk_wait_data waits for sk_receive_queue not empty, but in this case, the receive queue is not empty, but does not contain any skb that we can use. Add a "last skb seen on receive queue" argument to sk_wait_data, so that it sleeps until the receive queue has new skbs. Link: https://bugzilla.kernel.org/show_bug.cgi?id=99461 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=18493 Link: https://bugzilla.redhat.com/show_bug.cgi?id=1205258 Reported-by: Enrico Scholz <rh-bugzilla@ensc.de> Reported-by: Dan Searle <dan@censornet.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Currently, tcp_recvmsg enters a busy loop in sk_wait_data if called
with flags = MSG_WAITALL | MSG_PEEK.

sk_wait_data waits for sk_receive_queue not empty, but in this case,
the receive queue is not empty, but does not contain any skb that we
can use.

Add a "last skb seen on receive queue" argument to sk_wait_data, so
that it sleeps until the receive queue has new skbs.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=99461
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=18493
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1205258
Reported-by: Enrico Scholz <rh-bugzilla@ensc.de>
Reported-by: Dan Searle <dan@censornet.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sock_diag: don't broadcast kernel sockets 2015-06-30T17:00:26+00:00 Craig Gallek kraig@google.com 2015-06-30T16:49:32+00:00 b922622ec6efad1f28ad13053fd17e744614f77b Kernel sockets do not hold a reference for the network namespace to which they point. Socket destruction broadcasting relies on the network namespace and will cause the splat below when a kernel socket is destroyed. This fix simply ignores kernel sockets when they are destroyed. Reported as: general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU: 1 PID: 9130 Comm: kworker/1:1 Not tainted 4.1.0-gelk-debug+ #1 Workqueue: sock_diag_events sock_diag_broadcast_destroy_work Stack: ffff8800b9c586c0 ffff8800b9c586c0 ffff8800ac4692c0 ffff8800936d4a90 ffff8800352efd38 ffffffff8469a93e ffff8800352efd98 ffffffffc09b9b90 ffff8800352efd78 ffff8800ac4692c0 ffff8800b9c586c0 ffff8800831b6ab8 Call Trace: [<ffffffff8469a93e>] ? mutex_unlock+0xe/0x10 [<ffffffffc09b9b90>] ? inet_diag_handler_get_info+0x110/0x1fb [inet_diag] [<ffffffff845c868d>] netlink_broadcast+0x1d/0x20 [<ffffffff8469a93e>] ? mutex_unlock+0xe/0x10 [<ffffffff845b2bf5>] sock_diag_broadcast_destroy_work+0xd5/0x160 [<ffffffff8408ea97>] process_one_work+0x147/0x420 [<ffffffff8408f0f9>] worker_thread+0x69/0x470 [<ffffffff8409fda3>] ? preempt_count_sub+0xa3/0xf0 [<ffffffff8408f090>] ? rescuer_thread+0x320/0x320 [<ffffffff84093cd7>] kthread+0x107/0x120 [<ffffffff84093bd0>] ? kthread_create_on_node+0x1b0/0x1b0 [<ffffffff8469d31f>] ret_from_fork+0x3f/0x70 [<ffffffff84093bd0>] ? kthread_create_on_node+0x1b0/0x1b0 Tested: Using a debug kernel while 'ss -E' is running: ip netns add test-ns ip netns delete test-ns Fixes: eb4cb008529c sock_diag: define destruction multicast groups Fixes: 26abe14379f8 net: Modify sk_alloc to not reference count the netns of kernel sockets. Reported-by: Dave Jones <davej@codemonkey.org.uk> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Craig Gallek <kraig@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Kernel sockets do not hold a reference for the network namespace to
which they point.  Socket destruction broadcasting relies on the
network namespace and will cause the splat below when a kernel socket
is destroyed.

This fix simply ignores kernel sockets when they are destroyed.

Reported as:
general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
CPU: 1 PID: 9130 Comm: kworker/1:1 Not tainted 4.1.0-gelk-debug+ #1
Workqueue: sock_diag_events sock_diag_broadcast_destroy_work
Stack:
 ffff8800b9c586c0 ffff8800b9c586c0 ffff8800ac4692c0 ffff8800936d4a90
 ffff8800352efd38 ffffffff8469a93e ffff8800352efd98 ffffffffc09b9b90
 ffff8800352efd78 ffff8800ac4692c0 ffff8800b9c586c0 ffff8800831b6ab8
Call Trace:
 [<ffffffff8469a93e>] ? mutex_unlock+0xe/0x10
 [<ffffffffc09b9b90>] ? inet_diag_handler_get_info+0x110/0x1fb [inet_diag]
 [<ffffffff845c868d>] netlink_broadcast+0x1d/0x20
 [<ffffffff8469a93e>] ? mutex_unlock+0xe/0x10
 [<ffffffff845b2bf5>] sock_diag_broadcast_destroy_work+0xd5/0x160
 [<ffffffff8408ea97>] process_one_work+0x147/0x420
 [<ffffffff8408f0f9>] worker_thread+0x69/0x470
 [<ffffffff8409fda3>] ? preempt_count_sub+0xa3/0xf0
 [<ffffffff8408f090>] ? rescuer_thread+0x320/0x320
 [<ffffffff84093cd7>] kthread+0x107/0x120
 [<ffffffff84093bd0>] ? kthread_create_on_node+0x1b0/0x1b0
 [<ffffffff8469d31f>] ret_from_fork+0x3f/0x70
 [<ffffffff84093bd0>] ? kthread_create_on_node+0x1b0/0x1b0

Tested:
  Using a debug kernel while 'ss -E' is running:
  ip netns add test-ns
  ip netns delete test-ns

Fixes: eb4cb008529c sock_diag: define destruction multicast groups
Fixes: 26abe14379f8 net: Modify sk_alloc to not reference count the
  netns of kernel sockets.
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>

Signed-off-by: Craig Gallek <kraig@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Kill sock->sk_protinfo 2015-06-28T23:55:44+00:00 David Miller davem@davemloft.net 2015-06-25T13:19:15+00:00 1830fcea5bbed2719a9dc32aebe802f72ddf14ab No more users, so it can now be removed. Signed-off-by: David S. Miller <davem@davemloft.net> 
No more users, so it can now be removed.

Signed-off-by: David S. Miller <davem@davemloft.net>
sock_diag: define destruction multicast groups 2015-06-16T02:49:22+00:00 Craig Gallek kraig@google.com 2015-06-15T15:26:18+00:00 eb4cb008529ca08e0d8c0fa54e8f739520197a65 These groups will contain socket-destruction events for AF_INET/AF_INET6, IPPROTO_TCP/IPPROTO_UDP. Near the end of socket destruction, a check for listeners is performed. In the presence of a listener, rather than completely cleanup the socket, a unit of work will be added to a private work queue which will first broadcast information about the socket and then finish the cleanup operation. Signed-off-by: Craig Gallek <kraig@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
These groups will contain socket-destruction events for
AF_INET/AF_INET6, IPPROTO_TCP/IPPROTO_UDP.

Near the end of socket destruction, a check for listeners is
performed.  In the presence of a listener, rather than completely
cleanup the socket, a unit of work will be added to a private
work queue which will first broadcast information about the socket
and then finish the cleanup operation.

Signed-off-by: Craig Gallek <kraig@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-14T06:56:52+00:00 David S. Miller davem@davemloft.net 2015-06-14T06:56:52+00:00 25c43bf13b1657d9a2f6a2565e9159ce31517aa5 






net: don't wait for order-3 page allocation
2015-06-12T00:33:44+00:00

Shaohua Li
shli@fb.com

2015-06-11T23:50:48+00:00

fb05e7a89f500cfc06ae277bdc911b281928995d

We saw excessive direct memory compaction triggered by skb_page_frag_refill.
This causes performance issues and add latency. Commit 5640f7685831e0
introduces the order-3 allocation. According to the changelog, the order-3
allocation isn't a must-have but to improve performance. But direct memory
compaction has high overhead. The benefit of order-3 allocation can't
compensate the overhead of direct memory compaction.

This patch makes the order-3 page allocation atomic. If there is no memory
pressure and memory isn't fragmented, the alloction will still success, so we
don't sacrifice the order-3 benefit here. If the atomic allocation fails,
direct memory compaction will not be triggered, skb_page_frag_refill will
fallback to order-0 immediately, hence the direct memory compaction overhead is
avoided. In the allocation failure case, kswapd is waken up and doing
compaction, so chances are allocation could success next time.

alloc_skb_with_frags is the same.

The mellanox driver does similar thing, if this is accepted, we must fix
the driver too.

V3: fix the same issue in alloc_skb_with_frags as pointed out by Eric
V2: make the changelog clearer

Cc: Eric Dumazet <edumazet@google.com>
Cc: Chris Mason <clm@fb.com>
Cc: Debabrata Banerjee <dbavatar@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>





We saw excessive direct memory compaction triggered by skb_page_frag_refill.
This causes performance issues and add latency. Commit 5640f7685831e0
introduces the order-3 allocation. According to the changelog, the order-3
allocation isn't a must-have but to improve performance. But direct memory
compaction has high overhead. The benefit of order-3 allocation can't
compensate the overhead of direct memory compaction.

This patch makes the order-3 page allocation atomic. If there is no memory
pressure and memory isn't fragmented, the alloction will still success, so we
don't sacrifice the order-3 benefit here. If the atomic allocation fails,
direct memory compaction will not be triggered, skb_page_frag_refill will
fallback to order-0 immediately, hence the direct memory compaction overhead is
avoided. In the allocation failure case, kswapd is waken up and doing
compaction, so chances are allocation could success next time.

alloc_skb_with_frags is the same.

The mellanox driver does similar thing, if this is accepted, we must fix
the driver too.

V3: fix the same issue in alloc_skb_with_frags as pointed out by Eric
V2: make the changelog clearer

Cc: Eric Dumazet <edumazet@google.com>
Cc: Chris Mason <clm@fb.com>
Cc: Debabrata Banerjee <dbavatar@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>







net, swap: Remove a warning and clarify why sk_mem_reclaim is required when deactivating swap
2015-06-11T06:02:31+00:00

Mel Gorman
mgorman@suse.de

2015-06-11T01:02:04+00:00

5d753610277862fd8050901f38b6571b9500cdb6

Jeff Layton reported the following;

 [   74.232485] ------------[ cut here ]------------
 [   74.233354] WARNING: CPU: 2 PID: 754 at net/core/sock.c:364 sk_clear_memalloc+0x51/0x80()
 [   74.234790] Modules linked in: cts rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache xfs libcrc32c snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device nfsd snd_pcm snd_timer snd e1000 ppdev parport_pc joydev parport pvpanic soundcore floppy serio_raw i2c_piix4 pcspkr nfs_acl lockd virtio_balloon acpi_cpufreq auth_rpcgss grace sunrpc qxl drm_kms_helper ttm drm virtio_console virtio_blk virtio_pci ata_generic virtio_ring pata_acpi virtio
 [   74.243599] CPU: 2 PID: 754 Comm: swapoff Not tainted 4.1.0-rc6+ #5
 [   74.244635] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
 [   74.245546]  0000000000000000 0000000079e69e31 ffff8800d066bde8 ffffffff8179263d
 [   74.246786]  0000000000000000 0000000000000000 ffff8800d066be28 ffffffff8109e6fa
 [   74.248175]  0000000000000000 ffff880118d48000 ffff8800d58f5c08 ffff880036e380a8
 [   74.249483] Call Trace:
 [   74.249872]  [<ffffffff8179263d>] dump_stack+0x45/0x57
 [   74.250703]  [<ffffffff8109e6fa>] warn_slowpath_common+0x8a/0xc0
 [   74.251655]  [<ffffffff8109e82a>] warn_slowpath_null+0x1a/0x20
 [   74.252585]  [<ffffffff81661241>] sk_clear_memalloc+0x51/0x80
 [   74.253519]  [<ffffffffa0116c72>] xs_disable_swap+0x42/0x80 [sunrpc]
 [   74.254537]  [<ffffffffa01109de>] rpc_clnt_swap_deactivate+0x7e/0xc0 [sunrpc]
 [   74.255610]  [<ffffffffa03e4fd7>] nfs_swap_deactivate+0x27/0x30 [nfs]
 [   74.256582]  [<ffffffff811e99d4>] destroy_swap_extents+0x74/0x80
 [   74.257496]  [<ffffffff811ecb52>] SyS_swapoff+0x222/0x5c0
 [   74.258318]  [<ffffffff81023f27>] ? syscall_trace_leave+0xc7/0x140
 [   74.259253]  [<ffffffff81798dae>] system_call_fastpath+0x12/0x71
 [   74.260158] ---[ end trace 2530722966429f10 ]---

The warning in question was unnecessary but with Jeff's series the rules
are also clearer.  This patch removes the warning and updates the comment
to explain why sk_mem_reclaim() may still be called.

[jlayton: remove if (sk->sk_forward_alloc) conditional. As Leon
          points out that it's not needed.]

Cc: Leon Romanovsky <leon@leon.nu>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: David S. Miller <davem@davemloft.net>





Jeff Layton reported the following;

 [   74.232485] ------------[ cut here ]------------
 [   74.233354] WARNING: CPU: 2 PID: 754 at net/core/sock.c:364 sk_clear_memalloc+0x51/0x80()
 [   74.234790] Modules linked in: cts rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache xfs libcrc32c snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device nfsd snd_pcm snd_timer snd e1000 ppdev parport_pc joydev parport pvpanic soundcore floppy serio_raw i2c_piix4 pcspkr nfs_acl lockd virtio_balloon acpi_cpufreq auth_rpcgss grace sunrpc qxl drm_kms_helper ttm drm virtio_console virtio_blk virtio_pci ata_generic virtio_ring pata_acpi virtio
 [   74.243599] CPU: 2 PID: 754 Comm: swapoff Not tainted 4.1.0-rc6+ #5
 [   74.244635] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
 [   74.245546]  0000000000000000 0000000079e69e31 ffff8800d066bde8 ffffffff8179263d
 [   74.246786]  0000000000000000 0000000000000000 ffff8800d066be28 ffffffff8109e6fa
 [   74.248175]  0000000000000000 ffff880118d48000 ffff8800d58f5c08 ffff880036e380a8
 [   74.249483] Call Trace:
 [   74.249872]  [<ffffffff8179263d>] dump_stack+0x45/0x57
 [   74.250703]  [<ffffffff8109e6fa>] warn_slowpath_common+0x8a/0xc0
 [   74.251655]  [<ffffffff8109e82a>] warn_slowpath_null+0x1a/0x20
 [   74.252585]  [<ffffffff81661241>] sk_clear_memalloc+0x51/0x80
 [   74.253519]  [<ffffffffa0116c72>] xs_disable_swap+0x42/0x80 [sunrpc]
 [   74.254537]  [<ffffffffa01109de>] rpc_clnt_swap_deactivate+0x7e/0xc0 [sunrpc]
 [   74.255610]  [<ffffffffa03e4fd7>] nfs_swap_deactivate+0x27/0x30 [nfs]
 [   74.256582]  [<ffffffff811e99d4>] destroy_swap_extents+0x74/0x80
 [   74.257496]  [<ffffffff811ecb52>] SyS_swapoff+0x222/0x5c0
 [   74.258318]  [<ffffffff81023f27>] ? syscall_trace_leave+0xc7/0x140
 [   74.259253]  [<ffffffff81798dae>] system_call_fastpath+0x12/0x71
 [   74.260158] ---[ end trace 2530722966429f10 ]---

The warning in question was unnecessary but with Jeff's series the rules
are also clearer.  This patch removes the warning and updates the comment
to explain why sk_mem_reclaim() may still be called.

[jlayton: remove if (sk->sk_forward_alloc) conditional. As Leon
          points out that it's not needed.]

Cc: Leon Romanovsky <leon@leon.nu>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: David S. Miller <davem@davemloft.net>