linux.git/net/core/flow.c, branch v4.11

Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-13T03:25:04+00:00

Pull smp hotplug updates from Thomas Gleixner:
 "This is the final round of converting the notifier mess to the state
  machine. The removal of the notifiers and the related infrastructure
  will happen around rc1, as there are conversions outstanding in other
  trees.

  The whole exercise removed about 2000 lines of code in total and in
  course of the conversion several dozen bugs got fixed. The new
  mechanism allows to test almost every hotplug step standalone, so
  usage sites can exercise all transitions extensively.

  There is more room for improvement, like integrating all the
  pointlessly different architecture mechanisms of synchronizing,
  setting cpus online etc into the core code"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  tracing/rb: Init the CPU mask on allocation
  soc/fsl/qbman: Convert to hotplug state machine
  soc/fsl/qbman: Convert to hotplug state machine
  zram: Convert to hotplug state machine
  KVM/PPC/Book3S HV: Convert to hotplug state machine
  arm64/cpuinfo: Convert to hotplug state machine
  arm64/cpuinfo: Make hotplug notifier symmetric
  mm/compaction: Convert to hotplug state machine
  iommu/vt-d: Convert to hotplug state machine
  mm/zswap: Convert pool to hotplug state machine
  mm/zswap: Convert dst-mem to hotplug state machine
  mm/zsmalloc: Convert to hotplug state machine
  mm/vmstat: Convert to hotplug state machine
  mm/vmstat: Avoid on each online CPU loops
  mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()
  tracing/rb: Convert to hotplug state machine
  oprofile/nmi timer: Convert to hotplug state machine
  net/iucv: Use explicit clean up labels in iucv_init()
  x86/pci/amd-bus: Convert to hotplug state machine
  x86/oprofile/nmi: Convert to hotplug state machine
  ...

flowcache: Increase threshold for refusing new allocations

2016-11-23T05:37:09+00:00

The threshold for OOM protection is too small for systems with large
number of CPUs. Applications report ENOBUFs on connect() every 10
minutes.

The problem is that the variable net->xfrm.flow_cache_gc_count is a
global counter while the variable fc->high_watermark is a per-CPU
constant. Take the number of CPUs into account as well.

Fixes: 6ad3122a08e3 ("flowcache: Avoid OOM condition under preasure")
Reported-by: Lukáš Koldrt 
Tested-by: Jan Hejl 
Signed-off-by: Miroslav Urbanek 
Signed-off-by: Steffen Klassert

net/flowcache: Convert to hotplug state machine

2016-11-09T22:45:28+00:00

Install the callbacks via the state machine. Use multi state support to avoid
custom list handling for the multiple instances.

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Thomas Gleixner 
Cc: Steffen Klassert 
Cc: Herbert Xu 
Cc: netdev@vger.kernel.org
Cc: rt@linutronix.de
Cc: "David S. Miller" 
Link: http://lkml.kernel.org/r/20161103145021.28528-10-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner

flowcache: Avoid OOM condition under preasure

2016-03-17T09:28:42+00:00

We can hit an OOM condition if we are under presure because
we can not free the entries in gc_list fast enough. So add
a counter for the not yet freed entries in the gc_list and
refuse new allocations if the value is too high.

Signed-off-by: Steffen Klassert

flowcache: Fix kernel panic in flow_cache_flush_task

2015-02-05T22:38:53+00:00

flow_cache_flush_task references a structure member flow_cache_gc_work
where it should reference flow_cache_flush_task instead.

Kernel panic occurs on kernels using IPsec during XFRM garbage
collection. The garbage collection interval can be shortened using the
following sysctl settings:

net.ipv4.xfrm4_gc_thresh=4
net.ipv6.xfrm6_gc_thresh=4

With the default settings, our productions servers crash approximately
once a week. With the settings above, they crash immediately.

Fixes: ca925cf1534e ("flowcache: Make flow cache name space aware")
Reported-by: Tomáš Charvát 
Tested-by: Jan Hejl 
Signed-off-by: Miroslav Urbanek 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2014-04-07T21:55:46+00:00

Pull CPU hotplug notifiers registration fixes from Rafael Wysocki:
 "The purpose of this single series of commits from Srivatsa S Bhat
  (with a small piece from Gautham R Shenoy) touching multiple
  subsystems that use CPU hotplug notifiers is to provide a way to
  register them that will not lead to deadlocks with CPU online/offline
  operations as described in the changelog of commit 93ae4f978ca7f ("CPU
  hotplug: Provide lockless versions of callback registration
  functions").

  The first three commits in the series introduce the API and document
  it and the rest simply goes through the users of CPU hotplug notifiers
  and converts them to using the new method"

* tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits)
  net/iucv/iucv.c: Fix CPU hotplug callback registration
  net/core/flow.c: Fix CPU hotplug callback registration
  mm, zswap: Fix CPU hotplug callback registration
  mm, vmstat: Fix CPU hotplug callback registration
  profile: Fix CPU hotplug callback registration
  trace, ring-buffer: Fix CPU hotplug callback registration
  xen, balloon: Fix CPU hotplug callback registration
  hwmon, via-cputemp: Fix CPU hotplug callback registration
  hwmon, coretemp: Fix CPU hotplug callback registration
  thermal, x86-pkg-temp: Fix CPU hotplug callback registration
  octeon, watchdog: Fix CPU hotplug callback registration
  oprofile, nmi-timer: Fix CPU hotplug callback registration
  intel-idle: Fix CPU hotplug callback registration
  clocksource, dummy-timer: Fix CPU hotplug callback registration
  drivers/base/topology.c: Fix CPU hotplug callback registration
  acpi-cpufreq: Fix CPU hotplug callback registration
  zsmalloc: Fix CPU hotplug callback registration
  scsi, fcoe: Fix CPU hotplug callback registration
  scsi, bnx2fc: Fix CPU hotplug callback registration
  scsi, bnx2i: Fix CPU hotplug callback registration
  ...

net/core/flow.c: Fix CPU hotplug callback registration

2014-03-20T12:43:48+00:00

Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	/* Note the use of the double underscored version of the API */
	__register_cpu_notifier(&foobar_cpu_notifier);

	cpu_notifier_register_done();

Fix the code in net/core/flow.c by using this latter form of callback
registration.

Cc: Li RongQing 
Cc: Sasha Levin 
Cc: Andrew Morton 
Cc: Chris Metcalf 
Cc: Ingo Molnar 
Acked-by: David S. Miller 
Signed-off-by: Srivatsa S. Bhat 
Signed-off-by: Rafael J. Wysocki

flowcache: Fix resource leaks on namespace exit.

2014-03-12T19:31:18+00:00

We leak an active timer, the hotcpu notifier and all allocated
resources when we exit a namespace. Fix this by introducing a
flow_cache_fini() function where we release the resources before
we exit.

Fixes: ca925cf1534e ("flowcache: Make flow cache name space aware")
Reported-by: Jakub Kicinski 
Tested-by: Jakub Kicinski 
Cc: Eric Dumazet 
Cc: Fan Du 
Signed-off-by: Steffen Klassert 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

flowcache: restore a single flow_cache kmem_cache

2014-03-11T01:45:11+00:00

It is not legal to create multiple kmem_cache having the same name.

flowcache can use a single kmem_cache, no need for a per netns
one.

Fixes: ca925cf1534e ("flowcache: Make flow cache name space aware")
Reported-by: Jakub Kicinski 
Tested-by: Jakub Kicinski 
Tested-by: Fan Du 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

flowcache: Make flow cache name space aware

2014-02-12T06:02:11+00:00

Inserting a entry into flowcache, or flushing flowcache should be based
on per net scope. The reason to do so is flushing operation from fat
netns crammed with flow entries will also making the slim netns with only
a few flow cache entries go away in original implementation.

Since flowcache is tightly coupled with IPsec, so it would be easier to
put flow cache global parameters into xfrm namespace part. And one last
thing needs to do is bumping flow cache genid, and flush flow cache should
also be made in per net style.

Signed-off-by: Fan Du 
Signed-off-by: Steffen Klassert