diff mbox series

[4.9,25/80] tcp: cache line align MAX_TCP_HEADER

Message ID	20200501131522.465024046@linuxfoundation.org
State	Superseded
Headers	show Return-Path: <SRS0=1/SS=6P=vger.kernel.org=stable-owner@kernel.org> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org, Eric Dumazet <edumazet@google.com>, Soheil Hassas Yeganeh <soheil@google.com>, "David S. Miller" <davem@davemloft.net> Subject: [PATCH 4.9 25/80] tcp: cache line align MAX_TCP_HEADER Date: Fri, 1 May 2020 15:21:19 +0200 Message-Id: <20200501131522.465024046@linuxfoundation.org> In-Reply-To: <20200501131513.810761598@linuxfoundation.org> References: <20200501131513.810761598@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk
Series	None \| expand [4.9,02/80] net: ipv4: emulate READ_ONCE() on ->hdrincl bit-field in raw_sendmsg() [4.9,05/80] crypto: mxs-dcp - make symbols sha1_null_hash and sha256_null_hash static [4.9,06/80] vti4: removed duplicate log message. [4.9,10/80] ceph: dont skip updating wanted caps when cap is stale [4.9,11/80] pwm: rcar: Fix late Runtime PM enablement [4.9,13/80] ASoC: Intel: atom: Take the drv->lock mutex before calling sst_send_slot_map() [4.9,14/80] kernel/gcov/fs.c: gcov_seq_next() should increase position index [4.9,19/80] PCI/ASPM: Allow re-enabling Clock PM [4.9,20/80] ipv6: fix restrict IPV6_ADDRFORM operation [4.9,21/80] macsec: avoid to set wrong mtu [4.9,22/80] macvlan: fix null dereference in macvlan_device_event() [4.9,23/80] net: netrom: Fix potential nr_neigh refcnt leak in nr_add_node [4.9,25/80] tcp: cache line align MAX_TCP_HEADER [4.9,27/80] net: dsa: b53: Fix ARL register definitions [4.9,28/80] xfrm: Always set XFRM_TRANSFORMED in xfrm{4,6}_output_finish [4.9,31/80] iio: xilinx-xadc: Fix clearing interrupt when enabling trigger [4.9,32/80] iio: xilinx-xadc: Fix sequencer configuration for aux channels in simultaneous mode [4.9,38/80] overflow.h: Add arithmetic shift helper [4.9,41/80] ALSA: usb-audio: Fix usb audio refcnt leak when getting spdif [4.9,43/80] tpm/tpm_tis: Free IRQ if probing fails [4.9,44/80] KVM: Check validity of resolved slot when searching memslots [4.9,45/80] KVM: VMX: Enable machine check support for 32bit targets [4.9,46/80] tty: hvc: fix buffer overflow during hvc_alloc(). [4.9,48/80] usb-storage: Add unusual_devs entry for JMicron JMS566 [4.9,54/80] staging: vt6656: Fix drivers TBTT timing counter. [4.9,55/80] staging: vt6656: Power save stop wake_up_count wrap around. [4.9,57/80] UAS: fix deadlock in error handling and PM flushing work [4.9,59/80] remoteproc: Fix wrong rvring index computation [4.9,60/80] fuse: fix possibly missed wake-up after abort [4.9,63/80] nfsd: memory corruption in nfsd4_lock() [4.9,64/80] net/cxgb4: Check the return from t4_query_params properly [4.9,65/80] perf/core: fix parent pid/tid in task exit events [4.9,66/80] bpf, x86: Fix encoding for lower 8-bit registers in BPF_STX BPF_B [4.9,68/80] scsi: target: fix PR IN / READ FULL STATUS for FC [4.9,69/80] objtool: Fix CONFIG_UBSAN_TRAP unreachable warnings [4.9,71/80] xen/xenbus: ensure xenbus_map_ring_valloc() returns proper grant status [4.9,74/80] hwmon: (jc42) Fix name to have no illegal characters [4.9,77/80] ext4: dont perform block validity checks on the journal inode [4.9,79/80] ext4: unsigned int compared against zero

Commit Message

Greg KH May 1, 2020, 1:21 p.m. UTC

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 9bacd256f1354883d3c1402655153367982bba49 ]

TCP stack is dumb in how it cooks its output packets.

Depending on MAX_HEADER value, we might chose a bad ending point
for the headers.

If we align the end of TCP headers to cache line boundary, we
make sure to always use the smallest number of cache lines,
which always help.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/net/tcp.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff mbox series

Patch

--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -51,7 +51,7 @@  extern struct inet_hashinfo tcp_hashinfo
 extern struct percpu_counter tcp_orphan_count;
 void tcp_time_wait(struct sock *sk, int state, int timeo);
 
-#define MAX_TCP_HEADER	(128 + MAX_HEADER)
+#define MAX_TCP_HEADER	L1_CACHE_ALIGN(128 + MAX_HEADER)
 #define MAX_TCP_OPTION_SPACE 40
 #define TCP_MIN_SND_MSS		48
 #define TCP_MIN_GSO_SIZE	(TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE)