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2010-06-15netpoll: Fix RCU usageHerbert Xu
The use of RCU in netpoll is incorrect in a number of places: 1) The initial setting is lacking a write barrier. 2) The synchronize_rcu is in the wrong place. 3) Read barriers are missing. 4) Some places are even missing rcu_read_lock. 5) npinfo is zeroed after freeing. This patch fixes those issues. As most users are in BH context, this also converts the RCU usage to the BH variant. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-15Merge branch 'master' of /repos/git/net-next-2.6Patrick McHardy
Conflicts: include/net/netfilter/xt_rateest.h net/bridge/br_netfilter.c net/netfilter/nf_conntrack_core.c Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-15netfilter: xtables: idletimer target implementationLuciano Coelho
This patch implements an idletimer Xtables target that can be used to identify when interfaces have been idle for a certain period of time. Timers are identified by labels and are created when a rule is set with a new label. The rules also take a timeout value (in seconds) as an option. If more than one rule uses the same timer label, the timer will be restarted whenever any of the rules get a hit. One entry for each timer is created in sysfs. This attribute contains the timer remaining for the timer to expire. The attributes are located under the xt_idletimer class: /sys/class/xt_idletimer/timers/<label> When the timer expires, the target module sends a sysfs notification to the userspace, which can then decide what to do (eg. disconnect to save power). Cc: Timo Teras <timo.teras@iki.fi> Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-14ethtool: Revert incorrect indentation changesBen Hutchings
commit 97f8aefbbfb5aa5c9944e5fa8149f1fdaf71c7b6 "net: fix ethtool coding style errors and warnings" changed the indentation of several macro definitions in ethtool.h. These definitions line up in the diff where there is an extra character at the start of each line, but not in the resulting file. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-15agp: drop vmalloc flag.Dave Airlie
Since the code that was too ugly to live is upstream, we can use it now, instead of rolling our own. Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-06-14net: Make accesses to ->br_port safe for sparse RCUPaul E. McKenney
The new versions of the rcu_dereference() APIs requires that any pointers passed to one of these APIs be fully defined. The ->br_port field in struct net_device points to a struct net_bridge_port, which is an incomplete type. This commit therefore changes ->br_port to be a void*, and introduces a br_port() helper function to convert the type to struct net_bridge_port, and applies this new helper function where required. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: David Miller <davem@davemloft.net> Cc: Stephen Hemminger <shemminger@linux-foundation.org> Cc: Eric Dumazet <eric.dumazet@gmail.com>
2010-06-14vfs: add fs.h to define struct filePaul E. McKenney
The sparse RCU-pointer annotations require definition of the underlying type of any pointer passed to rcu_dereference() and friends. So fcheck_files() needs "struct file" to be defined, so include fs.h. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@ZenIV.linux.org.uk>
2010-06-14lockdep: Add an in_workqueue_context() lockdep-based test functionPaul E. McKenney
Some recent uses of RCU make use of workqueues. In these uses, execution within the context of a specific workqueue takes the place of the usual RCU read-side primitives such as rcu_read_lock(), and flushing of workqueues takes the place of the usual RCU grace-period primitives. Checking for correct use of rcu_dereference() in such cases requires a test of whether the code is executing in the context of a particular workqueue. This commit adds an in_workqueue_context() function that provides this test. This new function is only defined when lockdep is enabled, which allows it to be used as the second argument of rcu_dereference_check(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-06-14rcu: add __rcu API for later sparse checkingPaul E. McKenney
This commit defines an __rcu API, but provides only vacuous definitions for it. This breaks dependencies among most of the subsequent patches, allowing them to reach mainline asynchronously via whatever trees are appropriate. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Christopher Li <sparse@chrisli.org> Cc: Josh Triplett <josh@joshtriplett.org>
2010-06-14rcu: add an rcu_dereference_index_check()Paul E. McKenney
The sparse RCU-pointer checking relies on type magic that dereferences the pointer in question. This does not work if the pointer is in fact an array index. This commit therefore supplies a new RCU API that omits the sparse checking to continue to support rcu_dereference() on integers. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2010-06-14tree/tiny rcu: Add debug RCU head objectsMathieu Desnoyers
Helps finding racy users of call_rcu(), which results in hangs because list entries are overwritten and/or skipped. Changelog since v4: - Bissectability is now OK - Now generate a WARN_ON_ONCE() for non-initialized rcu_head passed to call_rcu(). Statically initialized objects are detected with object_is_static(). - Rename rcu_head_init_on_stack to init_rcu_head_on_stack. - Remove init_rcu_head() completely. Changelog since v3: - Include comments from Lai Jiangshan This new patch version is based on the debugobjects with the newly introduced "active state" tracker. Non-initialized entries are all considered as "statically initialized". An activation fixup (triggered by call_rcu()) takes care of performing the debug object initialization without issuing any warning. Since we cannot increase the size of struct rcu_head, I don't see much room to put an identifier for statically initialized rcu_head structures. So for now, we have to live without "activation without explicit init" detection. But the main purpose of this debug option is to detect double-activations (double call_rcu() use of a rcu_head before the callback is executed), which is correctly addressed here. This also detects potential internal RCU callback corruption, which would cause the callbacks to be executed twice. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> CC: David S. Miller <davem@davemloft.net> CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> CC: akpm@linux-foundation.org CC: mingo@elte.hu CC: laijs@cn.fujitsu.com CC: dipankar@in.ibm.com CC: josh@joshtriplett.org CC: dvhltc@us.ibm.com CC: niv@us.ibm.com CC: tglx@linutronix.de CC: peterz@infradead.org CC: rostedt@goodmis.org CC: Valdis.Kletnieks@vt.edu CC: dhowells@redhat.com CC: eric.dumazet@gmail.com CC: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
2010-06-14netfilter: nfnetlink_log: RCU conversion, part 2Eric Dumazet
- must use atomic_inc_not_zero() in instance_lookup_get() - must use hlist_add_head_rcu() instead of hlist_add_head() - must use hlist_del_rcu() instead of hlist_del() - Introduce NFULNL_COPY_DISABLED to stop lockless reader from using an instance, before we do final instance_put() on it. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-06-14Merge branch 'for-jens' of git://git.drbd.org/linux-2.6-drbd into for-linusJens Axboe
2010-06-14drbd: Fixed a race between disk-attach and unexpected state changesPhilipp Reisner
This was a very hard to trigger race condition. If we got a state packet from the peer, after drbd_nl_disk() has already changed the disk state to D_NEGOTIATING but after_state_ch() was not yet run by the worker, then receive_state() might called drbd_sync_handshake(), which in turn crashed when accessing p_uuid. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2010-06-13Merge branch 'sched-wq' of ../wq into cmwq-baseTejun Heo
2010-06-12net: Enable 64-bit net device statistics on 32-bit architecturesBen Hutchings
Use struct rtnl_link_stats64 as the statistics structure. On 32-bit architectures, insert 32 bits of padding after/before each field of struct net_device_stats to make its layout compatible with struct rtnl_link_stats64. Add an anonymous union in net_device; move stats into the union and add struct rtnl_link_stats64 stats64. Add net_device_ops::ndo_get_stats64, implementations of which will return a pointer to struct rtnl_link_stats64. Drivers that implement this operation must not update the structure asynchronously. Change dev_get_stats() to call ndo_get_stats64 if available, and to return a pointer to struct rtnl_link_stats64. Change callers of dev_get_stats() accordingly. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-12Merge branch 'bugzilla-13931-sleep-nvs' into releaseLen Brown
Conflicts: drivers/acpi/sleep.c Signed-off-by: Len Brown <len.brown@intel.com>
2010-06-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: wimax/i2400m: fix missing endian correction read in fw loader net8139: fix a race at the end of NAPI pktgen: Fix accuracy of inter-packet delay. pkt_sched: gen_estimator: add a new lock net: deliver skbs on inactive slaves to exact matches ipv6: fix ICMP6_MIB_OUTERRORS r8169: fix mdio_read and update mdio_write according to hw specs gianfar: Revive the driver for eTSEC devices (disable timestamping) caif: fix a couple range checks phylib: Add support for the LXT973 phy. net: Print num_rx_queues imbalance warning only when there are allocated queues
2010-06-11Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
2010-06-11Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 Conflicts: drivers/net/wireless/wl12xx/wl1271.h drivers/net/wireless/wl12xx/wl1271_cmd.h
2010-06-11writeback: simplify and split bdi_start_writebackChristoph Hellwig
bdi_start_writeback now never gets a superblock passed, so we can just remove that case. And to further untangle the code and flatten the call stack split it into two trivial helpers for it's two callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-06-10net: deliver skbs on inactive slaves to exact matchesJohn Fastabend
Currently, the accelerated receive path for VLAN's will drop packets if the real device is an inactive slave and is not one of the special pkts tested for in skb_bond_should_drop(). This behavior is different then the non-accelerated path and for pkts over a bonded vlan. For example, vlanx -> bond0 -> ethx will be dropped in the vlan path and not delivered to any packet handlers at all. However, bond0 -> vlanx -> ethx and bond0 -> ethx will be delivered to handlers that match the exact dev, because the VLAN path checks the real_dev which is not a slave and netif_recv_skb() doesn't drop frames but only delivers them to exact matches. This patch adds a sk_buff flag which is used for tagging skbs that would previously been dropped and allows the skb to continue to skb_netif_recv(). Here we add logic to check for the deliver_no_wcard flag and if it is set only deliver to handlers that match exactly. This makes both paths above consistent and gives pkt handlers a way to identify skbs that come from inactive slaves. Without this patch in some configurations skbs will be delivered to handlers with exact matches and in others be dropped out right in the vlan path. I have tested the following 4 configurations in failover modes and load balancing modes. # bond0 -> ethx # vlanx -> bond0 -> ethx # bond0 -> vlanx -> ethx # bond0 -> ethx | vlanx -> -- Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-10x86, mce: Add HW_ERR printk prefix for hardware error loggingHuang Ying
This makes hardware error related log in printk log more explicit. So that the users can report it to hardware vendor instead of LKML or software vendor. Signed-off-by: Huang Ying <ying.huang@intel.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> LKML-Reference: <1275295689.3444.462.camel@yhuang-dev.sh.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-06-10Input: matrix_keypad - add support for clustered irqLuotao Fu
This one adds support of a combined irq source for the whole matrix keypad. This can be useful if all rows and columns of the keypad are e.g. connected to a GPIO expander, which only has one interrupt line for all events on every single GPIO. Signed-off-by: Luotao Fu <l.fu@pengutronix.de> Acked-by: Eric Miao <eric.y.miao@gmail.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-06-10suspend: Move NVS save/restore code to generic suspend functionalityMatthew Garrett
Saving platform non-volatile state may be required for suspend to RAM as well as hibernation. Move it to more generic code. Signed-off-by: Matthew Garrett <mjg@redhat.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-by: Maxim Levitsky <maximlevitsky@gmail.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-06-10firewire: core: add CSR abdicate supportClemens Ladisch
Implement the abdicate bit, which is required for bus manager capable nodes and tested by the Base 1394 Test Suite. Finally, something to do at a command reset! :-) Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10firewire: core: add CSR MAINT_UTILITY supportClemens Ladisch
Implement the MAIN_UTILITY register, which is utterly optional but useful as a safe target for diagnostic read/write/broadcast transactions. Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10firewire: add CSR PRIORITY_BUDGET supportClemens Ladisch
If supported by the OHCI controller, implement the PRIORITY_BUDGET register, which is required for nodes that can use asynchronous priority arbitration. To allow the core to determine what features the lowlevel device supports, add a new card driver callback. Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-10firewire: core: add CSR SPLIT_TIMEOUT supportClemens Ladisch
Implement the SPLIT_TIMEOUT registers. Besides being required by the spec, this is desirable for some IIDC devices and necessary for many audio devices to be able to increase the timeout from userspace. Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
2010-06-09Merge branch 'perf/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core
2010-06-09misc: Fix allocation 'borrowed' by vhost_netAlan Cox
10, 233 is allocated officially to /dev/kmview which is shipping in Ubuntu and Debian distributions. vhost_net seem to have borrowed it without making a proper request and this causes regressions in the other distributions. vhost_net can use a dynamic minor so use that instead. Also update the file with a comment to try and avoid future misunderstandings. cc: stable@kernel.org Signed-off-by: Alan Cox <device@lanana.org> [ We should have caught this before 2.6.34 got released. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-09tracing: Remove kmemtrace ftrace pluginLi Zefan
We have been resisting new ftrace plugins and removing existing ones, and kmemtrace has been superseded by kmem trace events and perf-kmem, so we remove it. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> [ remove kmemtrace from the makefile, handle slob too ] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-06-09perf: Fix build breakage for architecutes without atomic64_tPeter Zijlstra
The local64.h include dependency was not dependent on PERF_EVENT=y, which meant that arch's without atomic64_t support ended up including it and failed to build. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission>
2010-06-09perf: Convert perf_event to local_tPeter Zijlstra
Since now all modification to event->count (and ->prev_count and ->period_left) are local to a cpu, change then to local64_t so we avoid the LOCK'ed ops. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09perf: Add perf_event::child_countPeter Zijlstra
Only child counters adding back their values into the parent counter are responsible for cross-cpu updates to event->count. So if we pull that out into a new child_count variable, we get an event->count that is only modified locally. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09perf: Simplify the ring-buffer logic: make perf_buffer_alloc() do everything ↵Peter Zijlstra
needed Currently there are perf_buffer_alloc() + perf_buffer_init() + some separate bits, fold it all into a single perf_buffer_alloc() and only leave the attachment to the event separate. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09perf: Rename perf_mmap_data to perf_bufferPeter Zijlstra
Rename to clarify code. s/perf_mmap_data/perf_buffer/g and selective s/data/buffer/g Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09perf: Cleanup {start,commit,cancel}_txn detailsPeter Zijlstra
Clarify some of the transactional group scheduling API details and change it so that a successfull ->commit_txn also closes the transaction. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1274803086.5882.1752.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09perf: Add non-exec mmap() trackingEric B Munson
Add the capacility to track data mmap()s. This can be used together with PERF_SAMPLE_ADDR for data profiling. Signed-off-by: Anton Blanchard <anton@samba.org> [Updated code for stable perf ABI] Signed-off-by: Eric B Munson <ebmunson@us.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1274193049-25997-1-git-send-email-ebmunson@us.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09perf, trace: Inline perf_swevent_put_recursion_context()Peter Zijlstra
Inline perf_swevent_put_recursion_context into perf_tp_event(), this shrinks the per trace template code footprint and saves a function call. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09sched: Add asymmetric group packing option for sibling domainMichael Neuling
Check to see if the group is packed in a sched doman. This is primarily intended to used at the sibling level. Some cores like POWER7 prefer to use lower numbered SMT threads. In the case of POWER7, it can move to lower SMT modes only when higher threads are idle. When in lower SMT modes, the threads will perform better since they share less core resources. Hence when we have idle threads, we want them to be the higher ones. This adds a hook into f_b_g() called check_asym_packing() to check the packing. This packing function is run on idle threads. It checks to see if the busiest CPU in this domain (core in the P7 case) has a higher CPU number than what where the packing function is being run on. If it is, calculate the imbalance and return the higher busier thread as the busiest group to f_b_g(). Here we are assuming a lower CPU number will be equivalent to a lower SMT thread number. It also creates a new SD_ASYM_PACKING flag to enable this feature at any scheduler domain level. It also creates an arch hook to enable this feature at the sibling level. The default function doesn't enable this feature. Based heavily on patch from Peter Zijlstra. Fixes from Srivatsa Vaddagiri. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20100608045702.2936CCC897@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09sched: Fix capacity calculations for SMT4Srivatsa Vaddagiri
Handle cpu capacity being reported as 0 on cores with more number of hardware threads. For example on a Power7 core with 4 hardware threads, core power is 1177 and thus power of each hardware thread is 1177/4 = 294. This low power can lead to capacity for each hardware thread being calculated as 0, which leads to tasks bouncing within the core madly! Fix this by reporting capacity for hardware threads as 1, provided their power is not scaled down significantly because of frequency scaling or real-time tasks usage of cpu. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arjan van de Ven <arjan@linux.intel.com> LKML-Reference: <20100608045702.21D03CC895@localhost.localdomain> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09sched: Change nohz idle load balancing logic to push modelVenkatesh Pallipadi
In the new push model, all idle CPUs indeed go into nohz mode. There is still the concept of idle load balancer (performing the load balancing on behalf of all the idle cpu's in the system). Busy CPU kicks the nohz balancer when any of the nohz CPUs need idle load balancing. The kickee CPU does the idle load balancing on behalf of all idle CPUs instead of the normal idle balance. This addresses the below two problems with the current nohz ilb logic: * the idle load balancer continued to have periodic ticks during idle and wokeup frequently, even though it did not have any rebalancing to do on behalf of any of the idle CPUs. * On x86 and CPUs that have APIC timer stoppage on idle CPUs, this periodic wakeup can result in a periodic additional interrupt on a CPU doing the timer broadcast. Also currently we are migrating the unpinned timers from an idle to the cpu doing idle load balancing (when all the cpus in the system are idle, there is no idle load balancing cpu and timers get added to the same idle cpu where the request was made. So the existing optimization works only on semi idle system). And In semi idle system, we no longer have periodic ticks on the idle load balancer CPU. Using that cpu will add more delays to the timers than intended (as that cpu's timer base may not be uptodate wrt jiffies etc). This was causing mysterious slowdowns during boot etc. For now, in the semi idle case, use the nearest busy cpu for migrating timers from an idle cpu. This is good for power-savings anyway. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1274486981.2840.46.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-09sched_clock: Add local_clock() API and improve documentationPeter Zijlstra
For people who otherwise get to write: cpu_clock(smp_processor_id()), there is now: local_clock(). Also, as per suggestion from Andrew, provide some documentation on the various clock interfaces, and minimize the unsigned long long vs u64 mess. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jens Axboe <jaxboe@fusionio.com> LKML-Reference: <1275052414.1645.52.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-08writeback: pay attention to wbc->nr_to_write in write_cache_pagesDave Chinner
If a filesystem writes more than one page in ->writepage, write_cache_pages fails to notice this and continues to attempt writeback when wbc->nr_to_write has gone negative - this trace was captured from XFS: wbc_writeback_start: towrt=1024 wbc_writepage: towrt=1024 wbc_writepage: towrt=0 wbc_writepage: towrt=-1 wbc_writepage: towrt=-5 wbc_writepage: towrt=-21 wbc_writepage: towrt=-85 This has adverse effects on filesystem writeback behaviour. write_cache_pages() needs to terminate after a certain number of pages are written, not after a certain number of calls to ->writepage are made. This is a regression introduced by 17bc6c30cf6bfffd816bdc53682dd46fc34a2cf4 ("vfs: Add no_nrwrite_index_update writeback control flag"), but cannot be reverted directly due to subsequent bug fixes that have gone in on top of it. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-08perf: Drop the skip argument from perf_arch_fetch_regs_callerFrederic Weisbecker
Drop this argument now that we always want to rewind only to the state of the first caller. It means frame pointers are not necessary anymore to reliably get the source of an event. But this also means we need this helper to be a macro now, as an inline function is not an option since we need to know when to provide a default implentation. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-06-08Merge branch 'sched-wq' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq into sched/core
2010-06-08sched: add hooks for workqueueTejun Heo
Concurrency managed workqueue needs to know when workers are going to sleep and waking up. Using these two hooks, cmwq keeps track of the current concurrency level and throttles execution of new works if it's too high and wakes up another worker from the sleep hook if it becomes too low. This patch introduces PF_WQ_WORKER to identify workqueue workers and adds the following two hooks. * wq_worker_waking_up(): called when a worker is woken up. * wq_worker_sleeping(): called when a worker is going to sleep and may return a pointer to a local task which should be woken up. The returned task is woken up using try_to_wake_up_local() which is simplified ttwu which is called under rq lock and can only wake up local tasks. Both hooks are currently defined as noop in kernel/workqueue_sched.h. Later cmwq implementation will replace them with proper implementation. These hooks are hard coded as they'll always be enabled. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Ingo Molnar <mingo@elte.hu>
2010-06-08sched: adjust when cpu_active and cpuset configurations are updated during ↵Tejun Heo
cpu on/offlining Currently, when a cpu goes down, cpu_active is cleared before CPU_DOWN_PREPARE starts and cpuset configuration is updated from a default priority cpu notifier. When a cpu is coming up, it's set before CPU_ONLINE but cpuset configuration again is updated from the same cpu notifier. For cpu notifiers, this presents an inconsistent state. Threads which a CPU_DOWN_PREPARE notifier expects to be bound to the CPU can be migrated to other cpus because the cpu is no more inactive. Fix it by updating cpu_active in the highest priority cpu notifier and cpuset configuration in the second highest when a cpu is coming up. Down path is updated similarly. This guarantees that all other cpu notifiers see consistent cpu_active and cpuset configuration. cpuset_track_online_cpus() notifier is converted to cpuset_update_active_cpus() which just updates the configuration and now called from cpuset_cpu_[in]active() notifiers registered from sched_init_smp(). If cpuset is disabled, cpuset_update_active_cpus() degenerates into partition_sched_domains() making separate notifier for !CONFIG_CPUSETS unnecessary. This problem is triggered by cmwq. During CPU_DOWN_PREPARE, hotplug callback creates a kthread and kthread_bind()s it to the target cpu, and the thread is expected to run on that cpu. * Ingo's test discovered __cpuinit/exit markups were incorrect. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Menage <menage@google.com>
2010-06-08sched: define and use CPU_PRI_* enums for cpu notifier prioritiesTejun Heo
Instead of hardcoding priority 10 and 20 in sched and perf, collect them into CPU_PRI_* enums. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>