linux_dsm_epyc7002/include
Kirill Tkhai f0b07bb151 net: Introduce net_rwsem to protect net_namespace_list
rtnl_lock() is used everywhere, and contention is very high.
When someone wants to iterate over alive net namespaces,
he/she has no a possibility to do that without exclusive lock.
But the exclusive rtnl_lock() in such places is overkill,
and it just increases the contention. Yes, there is already
for_each_net_rcu() in kernel, but it requires rcu_read_lock(),
and this can't be sleepable. Also, sometimes it may be need
really prevent net_namespace_list growth, so for_each_net_rcu()
is not fit there.

This patch introduces new rw_semaphore, which will be used
instead of rtnl_mutex to protect net_namespace_list. It is
sleepable and allows not-exclusive iterations over net
namespaces list. It allows to stop using rtnl_lock()
in several places (what is made in next patches) and makes
less the time, we keep rtnl_mutex. Here we just add new lock,
while the explanation of we can remove rtnl_lock() there are
in next patches.

Fine grained locks generally are better, then one big lock,
so let's do that with net_namespace_list, while the situation
allows that.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-29 13:47:53 -04:00
..
acpi ACPICA: Update version to 20180105 2018-02-06 10:32:13 +01:00
asm-generic mm/vmalloc: add interfaces to free unmapped page table 2018-03-22 17:07:01 -07:00
clocksource
crypto
drm drm/nouveau: prefer XBGR2101010 for addfb ioctl 2018-02-23 13:51:42 +01:00
dt-bindings net: phy: dp83867: Add binding for the CLK_OUT pin muxing option 2018-02-14 15:33:43 -05:00
keys
kvm KVM: arm/arm64: Reset mapped IRQs on VM reset 2018-03-14 18:29:14 +00:00
linux net: Introduce net_rwsem to protect net_namespace_list 2018-03-29 13:47:53 -04:00
math-emu
media media: dvb: update buffer mmaped flags and frame counter 2018-02-23 11:44:08 -05:00
memory
misc powerpc updates for 4.16 2018-02-02 10:01:04 -08:00
net net: Introduce net_rwsem to protect net_namespace_list 2018-03-29 13:47:53 -04:00
pcmcia
ras
rdma net: Drop NETDEV_UNREGISTER_FINAL 2018-03-26 11:34:00 -04:00
scsi SCSI fixes on 20180306 2018-03-07 10:50:15 -08:00
soc ARC fixes for 4.16-rc4 2018-03-01 14:32:23 -08:00
sound Merge branch 'topic/fixes' into for-linus 2018-02-12 09:36:26 +01:00
target
trace rxrpc: Trace call completion 2018-03-27 23:08:20 +01:00
uapi ethtool: Add support for configuring PFC stall prevention in ethtool 2018-03-26 13:46:46 -07:00
video fbdev changes for v4.16: 2018-02-07 13:10:43 -08:00
xen