aboutsummaryrefslogtreecommitdiff
path: root/include
AgeCommit message (Collapse)Author
2011-09-28rcu: Simplify unboosting checksPaul E. McKenney
Commit 7765be (Fix RCU_BOOST race handling current->rcu_read_unlock_special) introduced a new ->rcu_boosted field in the task structure. This is redundant because the existing ->rcu_boost_mutex will be non-NULL at any time that ->rcu_boosted is nonzero. Therefore, this commit removes ->rcu_boosted and tests ->rcu_boost_mutex instead. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Move __rcu_read_unlock()'s barrier() within if-statementPaul E. McKenney
We only need to constrain the compiler if we are actually exiting the top-level RCU read-side critical section. This commit therefore moves the first barrier() cal in __rcu_read_unlock() to inside the "if" statement, thus avoiding needless register flushes for inner rcu_read_unlock() calls. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Improve rcu_assign_pointer() and RCU_INIT_POINTER() documentationPaul E. McKenney
The differences between rcu_assign_pointer() and RCU_INIT_POINTER() are subtle, and it is easy to use the the cheaper RCU_INIT_POINTER() when the more-expensive rcu_assign_pointer() should have been used instead. The consequences of this mistake are quite severe. This commit therefore carefully lays out the situations in which it it permissible to use RCU_INIT_POINTER(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Make rcu_assign_pointer() unconditionally insert a memory barrierEric Dumazet
Recent changes to gcc give warning messages on rcu_assign_pointers()'s checks that allow it to determine when it is OK to omit the memory barrier. Stephen Hemminger tried a number of gcc tricks to silence this warning, but #pragmas and CPP macros do not work together in the way that would be required to make this work. However, we now have RCU_INIT_POINTER(), which already omits this memory barrier, and which therefore may be used when assigning NULL to an RCU-protected pointer that is accessible to readers. This commit therefore makes rcu_assign_pointer() unconditionally emit the memory barrier. Reported-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28nohz: Remove nohz_cpu_maskShi, Alex
RCU no longer uses this global variable, nor does anyone else. This commit therefore removes this variable. This reduces memory footprint and also removes some atomic instructions and memory barriers from the dyntick-idle path. Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Remove unused and redundant interfacesPaul E. McKenney
The rcu_dereference_bh_protected() and rcu_dereference_sched_protected() macros are synonyms for rcu_dereference_protected() and are not used anywhere in mainline. This commit therefore removes them. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Add grace-period, quiescent-state, and call_rcu trace eventsPaul E. McKenney
Add trace events to record grace-period start and end, quiescent states, CPUs noticing grace-period start and end, grace-period initialization, call_rcu() invocation, tasks blocking in RCU read-side critical sections, tasks exiting those same critical sections, force_quiescent_state() detection of dyntick-idle and offline CPUs, CPUs entering and leaving dyntick-idle mode (except from NMIs), CPUs coming online and going offline, and CPUs being kicked for staying in dyntick-idle mode for too long (as in many weeks, even on 32-bit systems). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> rcu: Add the rcu flavor to callback trace events The earlier trace events for registering RCU callbacks and for invoking them did not include the RCU flavor (rcu_bh, rcu_preempt, or rcu_sched). This commit adds the RCU flavor to those trace events. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Make TINY_RCU also use softirq for RCU_BOOST=nPaul E. McKenney
This patch #ifdefs TINY_RCU kthreads out of the kernel unless RCU_BOOST=y, thus eliminating context-switch overhead if RCU priority boosting has not been configured. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Add event-trace markers to TREE_RCU kthreadsPaul E. McKenney
Add event-trace markers to TREE_RCU kthreads to allow including these kthread's CPU time in the utilization calculations. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Add RCU type to callback-invocation tracingPaul E. McKenney
Add a string to the rcu_batch_start() and rcu_batch_end() trace messages that indicates the RCU type ("rcu_sched", "rcu_bh", or "rcu_preempt"). The trace messages for the actual invocations themselves are not marked, as it should be clear from the rcu_batch_start() and rcu_batch_end() events before and after. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Event-trace markers for computing RCU CPU utilizationPaul E. McKenney
This commit adds the trace_rcu_utilization() marker that is to be used to allow postprocessing scripts compute RCU's CPU utilization, give or take event-trace overhead. Note that we do not include RCU's dyntick-idle interface because event tracing requires RCU protection, which is not available in dyntick-idle mode. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Add event-tracing for RCU callback invocationPaul E. McKenney
There was recently some controversy about the overhead of invoking RCU callbacks. Add TRACE_EVENT()s to obtain fine-grained timings for the start and stop of a batch of callbacks and also for each callback invoked. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Abstract common code for RCU grace-period-wait primitivesPaul E. McKenney
Pull the code that waits for an RCU grace period into a single function, which is then called by synchronize_rcu() and friends in the case of TREE_RCU and TREE_PREEMPT_RCU, and from rcu_barrier() and friends in the case of TINY_RCU and TINY_PREEMPT_RCU. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-28rcu: Move rcu_head definition to types.hPaul E. McKenney
Take a first step towards untangling Linux kernel header files by placing the struct rcu_head definition into include/linux/types.h and including include/linux/types.h in include/linux/rcupdate.h where struct rcu_head used to be defined. The actual inclusion point for include/linux/types.h is with the rest of the #include directives rather than at the point where struct rcu_head used to be defined, as suggested by Mathieu Desnoyers. Once this is in place, then header files that need only rcu_head can include types.h rather than rcupdate.h. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2011-09-28rcu: Restore checks for blocking in RCU read-side critical sectionsPaul E. McKenney
Long ago, using TREE_RCU with PREEMPT would result in "scheduling while atomic" diagnostics if you blocked in an RCU read-side critical section. However, PREEMPT now implies TREE_PREEMPT_RCU, which defeats this diagnostic. This commit therefore adds a replacement diagnostic based on PROVE_RCU. Because rcu_lockdep_assert() and lockdep_rcu_dereference() are now being used for things that have nothing to do with rcu_dereference(), rename lockdep_rcu_dereference() to lockdep_rcu_suspicious() and add a third argument that is a string indicating what is suspicious. This third argument is passed in from a new third argument to rcu_lockdep_assert(). Update all calls to rcu_lockdep_assert() to add an informative third argument. Also, add a pair of rcu_lockdep_assert() calls from within rcu_note_context_switch(), one complaining if a context switch occurs in an RCU-bh read-side critical section and another complaining if a context switch occurs in an RCU-sched read-side critical section. These are present only if the PROVE_RCU kernel parameter is enabled. Finally, fix some checkpatch whitespace complaints in lockdep.c. Again, you must enable PROVE_RCU to see these new diagnostics. But you are enabling PROVE_RCU to check out new RCU uses in any case, aren't you? Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-09-27vfs: remove LOOKUP_NO_AUTOMOUNT flagLinus Torvalds
That flag no longer makes sense, since we don't look up automount points as eagerly any more. Additionally, it turns out that the NO_AUTOMOUNT handling was buggy to begin with: it would avoid automounting even for cases where we really *needed* to do the automount handling, and could return ENOENT for autofs entries that hadn't been instantiated yet. With our new non-eager automount semantics, one discussion has been about adding a AT_AUTOMOUNT flag to vfs_fstatat (and thus the newfstatat() and fstatat64() system calls), but it's probably not worth it: you can always force at least directory automounting by simply adding the final '/' to the filename, which works for *all* of the stat family system calls, old and new. So AT_NO_AUTOMOUNT (and thus LOOKUP_NO_AUTOMOUNT) really were just a result of our bad default behavior. Acked-by: Ian Kent <raven@themaw.net> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-26vfs pathname lookup: Add LOOKUP_AUTOMOUNT flagLinus Torvalds
Since we've now turned around and made LOOKUP_FOLLOW *not* force an automount, we want to add the ability to force an automount event on lookup even if we don't happen to have one of the other flags that force it implicitly (LOOKUP_OPEN, LOOKUP_DIRECTORY, LOOKUP_PARENT..) Most cases will never want to use this, since you'd normally want to delay automounting as long as possible, which usually implies LOOKUP_OPEN (when we open a file or directory, we really cannot avoid the automount any more). But Trond argued sufficiently forcefully that at a minimum bind mounting a file and quotactl will want to force the automount lookup. Some other cases (like nfs_follow_remote_path()) could use it too, although LOOKUP_DIRECTORY would work there as well. This commit just adds the flag and logic, no users yet, though. It also doesn't actually touch the LOOKUP_NO_AUTOMOUNT flag that is related, and was made irrelevant by the same change that made us not follow on LOOKUP_FOLLOW. Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Ian Kent <raven@themaw.net> Cc: Jeff Layton <jlayton@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-22Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6Linus Torvalds
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: [S390] kvm: extension capability for new address space layout [S390] kvm: fix address mode switching
2011-09-21Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
* 'for-linus' of git://git.kernel.dk/linux-block: floppy: use del_timer_sync() in init cleanup blk-cgroup: be able to remove the record of unplugged device block: Don't check QUEUE_FLAG_SAME_COMP in __blk_complete_request mm: Add comment explaining task state setting in bdi_forker_thread() mm: Cleanup clearing of BDI_pending bit in bdi_forker_thread() block: simplify force plug flush code a little bit block: change force plug flush call order block: Fix queue_flag update when rq_affinity goes from 2 to 1 block: separate priority boosting from REQ_META block: remove READ_META and WRITE_META xen-blkback: fixed indentation and comments xen-blkback: Don't disconnect backend until state switched to XenbusStateClosed.
2011-09-20[S390] kvm: extension capability for new address space layoutChristian Borntraeger
598841ca9919d008b520114d8a4378c4ce4e40a1 ([S390] use gmap address spaces for kvm guest images) changed kvm on s390 to use a separate address space for kvm guests. We can now put KVM guests anywhere in the user address mode with a size up to 8PB - as long as the memory is 1MB-aligned. This change was done without KVM extension capability bit. The change was added after 3.0, but we still have a chance to add a feature bit before 3.1 (keeping the releases in a sane state). We use number 71 to avoid collisions with other pending kvm patches as requested by Alexander Graf. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Avi Kivity <avi@redhat.com> Cc: Alexander Graf <agraf@suse.de> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2011-09-19Merge git://github.com/davem330/netLinus Torvalds
* git://github.com/davem330/net: tcp: fix validation of D-SACK tcp: fix build error if !CONFIG_SYN_COOKIES
2011-09-18tcp: fix build error if !CONFIG_SYN_COOKIESEric Dumazet
commit 946cedccbd7387 (tcp: Change possible SYN flooding messages) added a build error if CONFIG_SYN_COOKIES=n Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-18Merge branch 'for-linus' of git://git.infradead.org/users/sameo/mfd-2.6Linus Torvalds
* 'for-linus' of git://git.infradead.org/users/sameo/mfd-2.6: mfd: Fix omap-usb-host build failure mfd: Make omap-usb-host TLL mode work again mfd: Set MAX8997 irq pointer mfd: Fix initialisation of tps65910 interrupts mfd: Check for twl4030-madc NULL pointer mfd: Copy the device pointer to the twl4030-madc structure mfd: Rename wm8350 static gpio_set_debounce() mfd: Fix value of WM8994_CONFIGURE_GPIO
2011-09-18Merge git://github.com/davem330/netLinus Torvalds
* git://github.com/davem330/net: (62 commits) ipv6: don't use inetpeer to store metrics for routes. can: ti_hecc: include linux/io.h IRDA: Fix global type conflicts in net/irda/irsysctl.c v2 net: Handle different key sizes between address families in flow cache net: Align AF-specific flowi structs to long ipv4: Fix fib_info->fib_metrics leak caif: fix a potential NULL dereference sctp: deal with multiple COOKIE_ECHO chunks ibmveth: Fix checksum offload failure handling ibmveth: Checksum offload is always disabled ibmveth: Fix issue with DMA mapping failure ibmveth: Fix DMA unmap error pch_gbe: support ML7831 IOH pch_gbe: added the process of FIFO over run error pch_gbe: fixed the issue which receives an unnecessary packet. sfc: Use 64-bit writes for TX push where possible Revert "sfc: Use write-combining to reduce TX latency" and follow-ups bnx2x: Fix ethtool advertisement bnx2x: Fix 578xx link LED bnx2x: Fix XMAC loopback test ...
2011-09-16net: Handle different key sizes between address families in flow cachedpward
With the conversion of struct flowi to a union of AF-specific structs, some operations on the flow cache need to account for the exact size of the key. Signed-off-by: David Ward <david.ward@ll.mit.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-16net: Align AF-specific flowi structs to longDavid Ward
AF-specific flowi structs are now passed to flow_key_compare, which must also be aligned to a long. Signed-off-by: David Ward <david.ward@ll.mit.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-16sctp: deal with multiple COOKIE_ECHO chunksMax Matveev
Attempt to reduce the number of IP packets emitted in response to single SCTP packet (2e3216cd) introduced a complication - if a packet contains two COOKIE_ECHO chunks and nothing else then SCTP state machine corks the socket while processing first COOKIE_ECHO and then loses the association and forgets to uncork the socket. To deal with the issue add new SCTP command which can be used to set association explictly. Use this new command when processing second COOKIE_ECHO chunk to restore the context for SCTP state machine. Signed-off-by: Max Matveev <makc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-16Merge branch 'master' of ../netdev/David S. Miller
2011-09-15net: copy userspace buffers on device forwardingMichael S. Tsirkin
dev_forward_skb loops an skb back into host networking stack which might hang on the memory indefinitely. In particular, this can happen in macvtap in bridged mode. Copy the userspace fragments to avoid blocking the sender in that case. As this patch makes skb_copy_ubufs extern now, I also added some documentation and made it clear the SKBTX_DEV_ZEROCOPY flag automatically instead of doing it in all callers. This can be made into a separate patch if people feel it's worth it. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-15tcp: Change possible SYN flooding messagesEric Dumazet
"Possible SYN flooding on port xxxx " messages can fill logs on servers. Change logic to log the message only once per listener, and add two new SNMP counters to track : TCPReqQFullDoCookies : number of times a SYNCOOKIE was replied to client TCPReqQFullDrop : number of times a SYN request was dropped because syncookies were not enabled. Based on a prior patch from Tom Herbert, and suggestions from David. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-14drivers/gpio/gpio-generic.c: fix build errorsRussell King
Building a kernel with hotplug disabled results in a link failure: `bgpio_remove' referenced in section `___ksymtab_gpl+bgpio_remove' of drivers/built-in.o: defined in discarded section `.devexit.text' of drivers/built-in.o This is because of bgpio_remove() is exported. It is illegal to export symbols which are discarded either at link time or as part of an init/exit section. Fix this by dropping the __devexit attributation from bgpio_remove(). Also drop the __devinit attributation from bgpio_init(). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-14memcg: Revert "memcg: add memory.vmscan_stat"Johannes Weiner
Revert the post-3.0 commit 82f9d486e59f5 ("memcg: add memory.vmscan_stat"). The implementation of per-memcg reclaim statistics violates how memcg hierarchies usually behave: hierarchically. The reclaim statistics are accounted to child memcgs and the parent hitting the limit, but not to hierarchy levels in between. Usually, hierarchical statistics are perfectly recursive, with each level representing the sum of itself and all its children. Since this exports statistics to userspace, this may lead to confusion and problems with changing things after the release, so revert it now, we can try again later. Signed-off-by: Johannes Weiner <jweiner@redhat.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ying Han <yinghan@google.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-08regulator: fix kernel-doc warning in consumer.hRandy Dunlap
Fix kernel-doc warning about internal/private data by marking it as "private:" so that kernel-doc will ignore it. Warning(include/linux/regulator/consumer.h:128): No description found for parameter 'ret' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-08wireless: fix kernel-doc warning in net/cfg80211.hRandy Dunlap
Fix kernel-doc warning in net/cfg80211.h: Warning(include/net/cfg80211.h:1884): No description found for parameter 'registered' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-07Merge branch 'perf-fixes-for-linus' of git://tesla.tglx.de/git/linux-2.6-tipLinus Torvalds
* 'perf-fixes-for-linus' of git://tesla.tglx.de/git/linux-2.6-tip: x86, perf: Check that current->mm is alive before getting user callchain perf_event: Fix broken calc_timer_values() perf events: Fix slow and broken cgroup context switch code
2011-09-06mfd: Fix value of WM8994_CONFIGURE_GPIOMark Brown
This needs to be an out of band value for the register and on this device registers are 16 bit so we must shift left one to the 17th bit. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: stable@kernel.org Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2011-09-06fs/9p: Use protocol-defined value for lock/getlock 'type' field.Jim Garlick
Signed-off-by: Jim Garlick <garlick@llnl.gov> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-09-06fs/9p: Add OS dependent open flags in 9p protocolAneesh Kumar K.V
Some of the flags are OS/arch dependent we add a 9p protocol value which maps to asm-generic/fcntl.h values in Linux Based on the original patch from Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-08-30net: relax PKTINFO non local ipv6 udp xmit checkMaciej Żenczykowski
Allow transparent sockets to be less restrictive about the source ip of ipv6 udp packets being sent. Google-Bug-Id: 5018138 Signed-off-by: Maciej Żenczykowski <maze@google.com> CC: "Erik Kline" <ek@google.com> CC: "Lorenzo Colitti" <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (42 commits) netpoll: fix incorrect access to skb data in __netpoll_rx cassini: init before use in cas_interruptN. can: ti_hecc: Fix uninitialized spinlock in probe can: ti_hecc: Fix unintialized variable net: sh_eth: fix the compile error net/phy: fix DP83865 phy interrupt handler sendmmsg/sendmsg: fix unsafe user pointer access ibmveth: Fix leak when recycling skb and hypervisor returns error arp: fix rcu lockdep splat in arp_process() bridge: fix a possible use after free bridge: Pseudo-header required for the checksum of ICMPv6 mcast: Fix source address selection for multicast listener report MAINTAINERS: Update GIT trees for network development ath9k: Fix PS wrappers in ath9k_set_coverage_class carl9170: Fix mismatch in carl9170_op_set_key mutex lock-unlock wl12xx: add max_sched_scan_ssids value to the hw description wl12xx: Fix validation of pm_runtime_get_sync return value wl12xx: Remove obsolete testmode NVS push command bcma: add uevent to the bus, to autoload drivers ath9k_hw: Fix STA (AR9485) bringup issue due to incorrect MAC address ...
2011-08-29perf events: Fix slow and broken cgroup context switch codeStephane Eranian
The current cgroup context switch code was incorrect leading to bogus counts. Furthermore, as soon as there was an active cgroup event on a CPU, the context switch cost on that CPU would increase by a significant amount as demonstrated by a simple ping/pong example: $ ./pong Both processes pinned to CPU1, running for 10s 10684.51 ctxsw/s Now start a cgroup perf stat: $ perf stat -e cycles,cycles -A -a -G test -C 1 -- sleep 100 $ ./pong Both processes pinned to CPU1, running for 10s 6674.61 ctxsw/s That's a 37% penalty. Note that pong is not even in the monitored cgroup. The results shown by perf stat are bogus: $ perf stat -e cycles,cycles -A -a -G test -C 1 -- sleep 100 Performance counter stats for 'sleep 100': CPU1 <not counted> cycles test CPU1 16,984,189,138 cycles # 0.000 GHz The second 'cycles' event should report a count @ CPU clock (here 2.4GHz) as it is counting across all cgroups. The patch below fixes the bogus accounting and bypasses any cgroup switches in case the outgoing and incoming tasks are in the same cgroup. With this patch the same test now yields: $ ./pong Both processes pinned to CPU1, running for 10s 10775.30 ctxsw/s Start perf stat with cgroup: $ perf stat -e cycles,cycles -A -a -G test -C 1 -- sleep 10 Run pong outside the cgroup: $ /pong Both processes pinned to CPU1, running for 10s 10687.80 ctxsw/s The penalty is now less than 2%. And the results for perf stat are correct: $ perf stat -e cycles,cycles -A -a -G test -C 1 -- sleep 10 Performance counter stats for 'sleep 10': CPU1 <not counted> cycles test # 0.000 GHz CPU1 23,933,981,448 cycles # 0.000 GHz Now perf stat reports the correct counts for for the non cgroup event. If we run pong inside the cgroup, then we also get the correct counts: $ perf stat -e cycles,cycles -A -a -G test -C 1 -- sleep 10 Performance counter stats for 'sleep 10': CPU1 22,297,726,205 cycles test # 0.000 GHz CPU1 23,933,981,448 cycles # 0.000 GHz 10.001457237 seconds time elapsed Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110825135803.GA4697@quad Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-08-26All Arch: remove linkage for sys_nfsservctl system callNeilBrown
The nfsservctl system call is now gone, so we should remove all linkage for it. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-26Merge branch 'tty-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 * 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: omap-serial: Allow IXON and IXOFF to be disabled. TTY: serial, document ignoring of uart->ops->startup error TTY: pty, fix pty counting 8250: Fix race condition in serial8250_backup_timeout(). serial/8250_pci: delete duplicate data definition 8250_pci: add support for Rosewill RC-305 4x serial port card tty: Add "spi:" prefix for spi modalias atmel_serial: fix atmel_default_console_device serial: 8250_pnp: add Intermec CV60 touchscreen device drivers/serial/ucc_uart.c: Fix compiler warning pch_uart: Set PCIe bus number using probe parameter serial: samsung: Fix build error
2011-08-26Merge branch 'driver-core-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6 * 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: drivers:misc: ti-st: fix unexpected UART close drivers:misc: ti-st: free skb on firmware download drivers:misc: ti-st: wait for completion at fail drivers:misc: ti-st: reinit completion before send drivers:misc: ti-st: fail-safe on wrong pkt type drivers:misc: ti-st: reinit completion on ver read drivers:misc:ti-st: platform hooks for chip states drivers:misc: ti-st: avoid a misleading dbg msg base/devres.c: quiet sparse noise about context imbalance pti: add missing CONFIG_PCI dependency drivers/base/devtmpfs.c: correct annotation of `setup_done' driver core: fix kernel-doc warning in platform.c firmware: fix google/gsmi.c build warning
2011-08-26Merge branch 'master' of ↵John W. Linville
git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless into for-davem
2011-08-25backlight: add a callback 'notify_after' for backlight controlDilan Lee
We need a callback to do some things after pwm_enable, pwm_disable and pwm_config. Signed-off-by: Dilan Lee <dilee@nvidia.com> Reviewed-by: Robert Morell <rmorell@nvidia.com> Reviewed-by: Arun Murthy <arun.murthy@stericsson.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-25rapidio: fix use of non-compatible registersAlexandre Bounine
Replace/remove use of RIO v.1.2 registers/bits that are not forward-compatible with newer versions of RapidIO specification. RapidIO specification v.1.3 removed Write Port CSR, Doorbell CSR, Mailbox CSR and Mailbox and Doorbell bits of the PEF CAR. Use of removed (since RIO v.1.3) register bits affects users of currently available 1.3 and 2.x compliant devices who may use not so recent kernel versions. Removing checks for unsupported bits makes corresponding routines compatible with all versions of RapidIO specification. Therefore, backporting makes stable kernel versions compliant with RIO v.1.3 and later as well. Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Li Yang <leoli@freescale.com> Cc: Thomas Moll <thomas.moll@sysgo.com> Cc: Chul Kim <chul.kim@idt.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-25MAINTAINERS: Evgeniy has movedEvgeniy Polyakov
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-25lockdep: Add helper function for dir vs file i_mutex annotationJosh Boyer
Purely in-memory filesystems do not use the inode hash as the dcache tells us if an entry already exists. As a result, they do not call unlock_new_inode, and thus directory inodes do not get put into a different lockdep class for i_sem. We need the different lockdep classes, because the locking order for i_mutex is different for directory inodes and regular inodes. Directory inodes can do "readdir()", which takes i_mutex *before* possibly taking mm->mmap_sem (due to a page fault while copying the directory entry to user space). In contrast, regular inodes can be mmap'ed, which takes mm->mmap_sem before accessing i_mutex. The two cases can never happen for the same inode, so no real deadlock can occur, but without the different lockdep classes, lockdep cannot understand that. As a result, if CONFIG_DEBUG_LOCK_ALLOC is set, this can lead to false positives from lockdep like below: find/645 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [<ffffffff81109514>] might_fault+0x5c/0xac but task is already holding lock: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffff81149f34>] vfs_readdir+0x5b/0xb4 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#15){+.+.+.}: [<ffffffff8108ac26>] lock_acquire+0xbf/0x103 [<ffffffff814db822>] __mutex_lock_common+0x4c/0x361 [<ffffffff814dbc46>] mutex_lock_nested+0x40/0x45 [<ffffffff811daa87>] hugetlbfs_file_mmap+0x82/0x110 [<ffffffff81111557>] mmap_region+0x258/0x432 [<ffffffff811119dd>] do_mmap_pgoff+0x2ac/0x306 [<ffffffff81111b4f>] sys_mmap_pgoff+0x118/0x16a [<ffffffff8100c858>] sys_mmap+0x22/0x24 [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b -> #0 (&mm->mmap_sem){++++++}: [<ffffffff8108a4bc>] __lock_acquire+0xa1a/0xcf7 [<ffffffff8108ac26>] lock_acquire+0xbf/0x103 [<ffffffff81109541>] might_fault+0x89/0xac [<ffffffff81149cff>] filldir+0x6f/0xc7 [<ffffffff811586ea>] dcache_readdir+0x67/0x205 [<ffffffff81149f54>] vfs_readdir+0x7b/0xb4 [<ffffffff8114a073>] sys_getdents+0x7e/0xd1 [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b This patch moves the directory vs file lockdep annotation into a helper function that can be called by in-memory filesystems and has hugetlbfs call it. Signed-off-by: Josh Boyer <jwboyer@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-25Merge branch 'urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback * 'urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback: squeeze max-pause area and drop pass-good area