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authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-03 08:08:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-03 08:08:17 -0700
commitdd5cdb48edfd34401799056a9acf61078d773f90 (patch)
tree8e251fb4a4c196540fe9b6a6d8b13275f93a057c /kernel/events
parent1e1a4e8f439113b7820bc7150569f685e1cc2b43 (diff)
parent62da98656b62a5ca57f22263705175af8ded5aa1 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller: "Another merge window, another set of networking changes. I've heard rumblings that the lightweight tunnels infrastructure has been voted networking change of the year. But what do I know? 1) Add conntrack support to openvswitch, from Joe Stringer. 2) Initial support for VRF (Virtual Routing and Forwarding), which allows the segmentation of routing paths without using multiple devices. There are some semantic kinks to work out still, but this is a reasonably strong foundation. From David Ahern. 3) Remove spinlock fro act_bpf fast path, from Alexei Starovoitov. 4) Ignore route nexthops with a link down state in ipv6, just like ipv4. From Andy Gospodarek. 5) Remove spinlock from fast path of act_gact and act_mirred, from Eric Dumazet. 6) Document the DSA layer, from Florian Fainelli. 7) Add netconsole support to bcmgenet, systemport, and DSA. Also from Florian Fainelli. 8) Add Mellanox Switch Driver and core infrastructure, from Jiri Pirko. 9) Add support for "light weight tunnels", which allow for encapsulation and decapsulation without bearing the overhead of a full blown netdevice. From Thomas Graf, Jiri Benc, and a cast of others. 10) Add Identifier Locator Addressing support for ipv6, from Tom Herbert. 11) Support fragmented SKBs in iwlwifi, from Johannes Berg. 12) Allow perf PMUs to be accessed from eBPF programs, from Kaixu Xia. 13) Add BQL support to 3c59x driver, from Loganaden Velvindron. 14) Stop using a zero TX queue length to mean that a device shouldn't have a qdisc attached, use an explicit flag instead. From Phil Sutter. 15) Use generic geneve netdevice infrastructure in openvswitch, from Pravin B Shelar. 16) Add infrastructure to avoid re-forwarding a packet in software that was already forwarded by a hardware switch. From Scott Feldman. 17) Allow AF_PACKET fanout function to be implemented in a bpf program, from Willem de Bruijn" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1458 commits) netfilter: nf_conntrack: make nf_ct_zone_dflt built-in netfilter: nf_dup{4, 6}: fix build error when nf_conntrack disabled net: fec: clear receive interrupts before processing a packet ipv6: fix exthdrs offload registration in out_rt path xen-netback: add support for multicast control bgmac: Update fixed_phy_register() sock, diag: fix panic in sock_diag_put_filterinfo flow_dissector: Use 'const' where possible. flow_dissector: Fix function argument ordering dependency ixgbe: Resolve "initialized field overwritten" warnings ixgbe: Remove bimodal SR-IOV disabling ixgbe: Add support for reporting 2.5G link speed ixgbe: fix bounds checking in ixgbe_setup_tc for 82598 ixgbe: support for ethtool set_rxfh ixgbe: Avoid needless PHY access on copper phys ixgbe: cleanup to use cached mask value ixgbe: Remove second instance of lan_id variable ixgbe: use kzalloc for allocating one thing flow: Move __get_hash_from_flowi{4,6} into flow_dissector.c ixgbe: Remove unused PCI bus types ...
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index ae16867670a9..e8183895691c 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3222,6 +3222,59 @@ static inline u64 perf_event_count(struct perf_event *event)
return __perf_event_count(event);
}
+/*
+ * NMI-safe method to read a local event, that is an event that
+ * is:
+ * - either for the current task, or for this CPU
+ * - does not have inherit set, for inherited task events
+ * will not be local and we cannot read them atomically
+ * - must not have a pmu::count method
+ */
+u64 perf_event_read_local(struct perf_event *event)
+{
+ unsigned long flags;
+ u64 val;
+
+ /*
+ * Disabling interrupts avoids all counter scheduling (context
+ * switches, timer based rotation and IPIs).
+ */
+ local_irq_save(flags);
+
+ /* If this is a per-task event, it must be for current */
+ WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) &&
+ event->hw.target != current);
+
+ /* If this is a per-CPU event, it must be for this CPU */
+ WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) &&
+ event->cpu != smp_processor_id());
+
+ /*
+ * It must not be an event with inherit set, we cannot read
+ * all child counters from atomic context.
+ */
+ WARN_ON_ONCE(event->attr.inherit);
+
+ /*
+ * It must not have a pmu::count method, those are not
+ * NMI safe.
+ */
+ WARN_ON_ONCE(event->pmu->count);
+
+ /*
+ * If the event is currently on this CPU, its either a per-task event,
+ * or local to this CPU. Furthermore it means its ACTIVE (otherwise
+ * oncpu == -1).
+ */
+ if (event->oncpu == smp_processor_id())
+ event->pmu->read(event);
+
+ val = local64_read(&event->count);
+ local_irq_restore(flags);
+
+ return val;
+}
+
static u64 perf_event_read(struct perf_event *event)
{
/*
@@ -8718,6 +8771,31 @@ void perf_event_delayed_put(struct task_struct *task)
WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
}
+struct perf_event *perf_event_get(unsigned int fd)
+{
+ int err;
+ struct fd f;
+ struct perf_event *event;
+
+ err = perf_fget_light(fd, &f);
+ if (err)
+ return ERR_PTR(err);
+
+ event = f.file->private_data;
+ atomic_long_inc(&event->refcount);
+ fdput(f);
+
+ return event;
+}
+
+const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
+{
+ if (!event)
+ return ERR_PTR(-EINVAL);
+
+ return &event->attr;
+}
+
/*
* inherit a event from parent task to child task:
*/