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linux/include
Eric Dumazet 6a321cb370 net: netif_tx_queue_stopped too expensive
netif_tx_queue_stopped(txq) is most of the time false.

Yet its cost is very expensive on SMP.

static inline int netif_tx_queue_stopped(const struct netdev_queue *dev_queue)
{
	return test_bit(__QUEUE_STATE_XOFF, &dev_queue->state);
}

I saw this on oprofile hunting and bnx2 driver bnx2_tx_int().

We probably should split "struct netdev_queue" in two parts, one
being read mostly.

__netif_tx_lock() touches _xmit_lock & xmit_lock_owner, these
deserve a separate cache line.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-28 04:43:42 -07:00
..
acpi Merge branches 'release', 'APERF', 'ARAT', 'misc', 'kelvin', 'device-lock' and 'bjorn.notify' into release 2009-04-07 18:18:42 -04:00
asm-arm
asm-generic percpu: unbreak alpha percpu 2009-04-10 21:36:18 +02:00
asm-h8300
asm-m32r Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
crypto
drm
keys
linux net: netif_tx_queue_stopped too expensive 2009-04-28 04:43:42 -07:00
math-emu
media V4L/DVB (11381): ivtv/cx18: remove VIDIOC_INT_S_AUDIO_ROUTING debug support. 2009-04-06 21:44:28 -03:00
mtd
net snmp: add missing counters for RFC 4293 2009-04-27 02:45:02 -07:00
pcmcia
rdma
rxrpc
scsi PM/Hibernate: Wait for SCSI devices scan to complete during resume 2009-04-13 11:37:07 -07:00
sound
trace tracing/syscalls: use a dedicated file header 2009-04-09 05:43:32 +02:00
video tdfxfb: move I2C functionality into the tdfxfb 2009-04-07 08:31:08 -07:00
xen
Kbuild