- 06 May, 2011 20 commits
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Paul E. McKenney authored
Verify that rcu_head structures are aligned to a four-byte boundary. This check is enabled by CONFIG_DEBUG_OBJECTS_RCU_HEAD. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Mathieu Desnoyers authored
The prohibition of DEBUG_OBJECTS_RCU_HEAD from !PREEMPT was due to the fixup actions. So just produce a warning from !PREEMPT. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
Increment a per-CPU counter on each pass through rcu_cpu_kthread()'s service loop, and add it to the rcudata trace output. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
This commit adds the age in jiffies of the current grace period along with the duration in jiffies of the longest grace period since boot to the rcu/rcugp debugfs file. It also adds an additional "O" state to kthread tracing to differentiate between the kthread waiting due to having nothing to do on the one hand and waiting due to being on the wrong CPU on the other hand. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Paul E. McKenney authored
The rcu_initiate_boost_trace() function mis-attributed refusals to initiate RCU priority boosting that were in fact due to its not yet being time to boost. This patch fixes the faulty comparison. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Paul E. McKenney authored
This commit documents the new debugfs rcu/rcutorture and rcu/rcuboost trace files. The description has been updated as suggested by Josh Triplett. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Paul E. McKenney authored
It is not possible to accurately correlate rcutorture output with that of debugfs. This patch therefore adds a debugfs file that prints out the rcutorture version number, permitting easy correlation. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
Add tracing to help debugging situations when RCU's kthreads are not running but are supposed to be. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
This commit adds an indication of the state of the callback queue using a string of four characters following the "ql=" integer queue length. The first character is "N" if there are callbacks that have been queued that are not yet ready to be handled by the next grace period, or "." otherwise. The second character is "R" if there are callbacks queued that are ready to be handled by the next grace period, or "." otherwise. The third character is "W" if there are callbacks waiting for the current grace period, or "." otherwise. Finally, the fourth character is "D" if there are callbacks that have been handled by a prior grace period and are waiting to be invoked, or ".". Note that callbacks that are in the process of being invoked are not shown. These callbacks would have been removed from the rcu_data structure's list by rcu_do_batch() prior to being executed. (These callbacks are also not reflected in the "ql=" total, FWIW.) Also, document the new callback-queue trace information. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
The trace.txt file had obsolete output for the debugfs rcu/rcudata file, so update it. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
Includes total number of tasks boosted, number boosted on behalf of each of normal and expedited grace periods, and statistics on attempts to initiate boosting that failed for various reasons. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
The n_rcu_torture_boost_allocerror and n_rcu_torture_boost_afferror statistics are not actually incremented anymore, so eliminate them. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
The scheduler does not appear to take kindly to having multiple real-time threads bound to a CPU that is going offline. So this commit is a temporary hack-around to avoid that happening. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Paul E. McKenney authored
If you are doing CPU hotplug operations, it is best not to have CPU-bound realtime tasks running CPU-bound on the outgoing CPU. So this commit makes per-CPU kthreads run at non-realtime priority during that time. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
The scheduler has had some heartburn in the past when too many real-time kthreads were affinitied to the outgoing CPU. So, this commit lightens the load by forcing the per-rcu_node and the boost kthreads off of the outgoing CPU. Note that RCU's per-CPU kthread remains on the outgoing CPU until the bitter end, as it must in order to preserve correctness. Also avoid disabling hardirqs across calls to set_cpus_allowed_ptr(), given that this function can block. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Paul E. McKenney authored
Add priority boosting for TREE_PREEMPT_RCU, similar to that for TINY_PREEMPT_RCU. This is enabled by the default-off RCU_BOOST kernel parameter. The priority to which to boost preempted RCU readers is controlled by the RCU_BOOST_PRIO kernel parameter (defaulting to real-time priority 1) and the time to wait before boosting the readers who are blocking a given grace period is controlled by the RCU_BOOST_DELAY kernel parameter (defaulting to 500 milliseconds). Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
If RCU priority boosting is to be meaningful, callback invocation must be boosted in addition to preempted RCU readers. Otherwise, in presence of CPU real-time threads, the grace period ends, but the callbacks don't get invoked. If the callbacks don't get invoked, the associated memory doesn't get freed, so the system is still subject to OOM. But it is not reasonable to priority-boost RCU_SOFTIRQ, so this commit moves the callback invocations to a kthread, which can be boosted easily. Also add comments and properly synchronized all accesses to rcu_cpu_kthread_task, as suggested by Lai Jiangshan. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
Combine the current TREE_PREEMPT_RCU ->blocked_tasks[] lists in the rcu_node structure into a single ->blkd_tasks list with ->gp_tasks and ->exp_tasks tail pointers. This is in preparation for RCU priority boosting, which will add a third dimension to the combinatorial explosion in the ->blocked_tasks[] case, but simply a third pointer in the new ->blkd_tasks case. Also update documentation to reflect blocked_tasks[] merge Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
Commit d09b62df fixed grace-period synchronization, but left some smp_mb() invocations in rcu_process_callbacks() that are no longer needed, but sheer paranoia prevented them from being removed. This commit removes them and provides a proof of correctness in their absence. It also adds a memory barrier to rcu_report_qs_rsp() immediately before the update to rsp->completed in order to handle the theoretical possibility that the compiler or CPU might move massive quantities of code into a lock-based critical section. This also proves that the sheer paranoia was not entirely unjustified, at least from a theoretical point of view. In addition, the old dyntick-idle synchronization depended on the fact that grace periods were many milliseconds in duration, so that it could be assumed that no dyntick-idle CPU could reorder a memory reference across an entire grace period. Unfortunately for this design, the addition of expedited grace periods breaks this assumption, which has the unfortunate side-effect of requiring atomic operations in the functions that track dyntick-idle state for RCU. (There is some hope that the algorithms used in user-level RCU might be applied here, but some work is required to handle the NMIs that user-space applications can happily ignore. For the short term, better safe than sorry.) This proof assumes that neither compiler nor CPU will allow a lock acquisition and release to be reordered, as doing so can result in deadlock. The proof is as follows: 1. A given CPU declares a quiescent state under the protection of its leaf rcu_node's lock. 2. If there is more than one level of rcu_node hierarchy, the last CPU to declare a quiescent state will also acquire the ->lock of the next rcu_node up in the hierarchy, but only after releasing the lower level's lock. The acquisition of this lock clearly cannot occur prior to the acquisition of the leaf node's lock. 3. Step 2 repeats until we reach the root rcu_node structure. Please note again that only one lock is held at a time through this process. The acquisition of the root rcu_node's ->lock must occur after the release of that of the leaf rcu_node. 4. At this point, we set the ->completed field in the rcu_state structure in rcu_report_qs_rsp(). However, if the rcu_node hierarchy contains only one rcu_node, then in theory the code preceding the quiescent state could leak into the critical section. We therefore precede the update of ->completed with a memory barrier. All CPUs will therefore agree that any updates preceding any report of a quiescent state will have happened before the update of ->completed. 5. Regardless of whether a new grace period is needed, rcu_start_gp() will propagate the new value of ->completed to all of the leaf rcu_node structures, under the protection of each rcu_node's ->lock. If a new grace period is needed immediately, this propagation will occur in the same critical section that ->completed was set in, but courtesy of the memory barrier in #4 above, is still seen to follow any pre-quiescent-state activity. 6. When a given CPU invokes __rcu_process_gp_end(), it becomes aware of the end of the old grace period and therefore makes any RCU callbacks that were waiting on that grace period eligible for invocation. If this CPU is the same one that detected the end of the grace period, and if there is but a single rcu_node in the hierarchy, we will still be in the single critical section. In this case, the memory barrier in step #4 guarantees that all callbacks will be seen to execute after each CPU's quiescent state. On the other hand, if this is a different CPU, it will acquire the leaf rcu_node's ->lock, and will again be serialized after each CPU's quiescent state for the old grace period. On the strength of this proof, this commit therefore removes the memory barriers from rcu_process_callbacks() and adds one to rcu_report_qs_rsp(). The effect is to reduce the number of memory barriers by one and to reduce the frequency of execution from about once per scheduling tick per CPU to once per grace period. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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Paul E. McKenney authored
The RCU CPU stall warnings can now be controlled using the rcu_cpu_stall_suppress boot-time parameter or via the same parameter from sysfs. There is therefore no longer any reason to have kernel config parameters for this feature. This commit therefore removes the RCU_CPU_STALL_DETECTOR and RCU_CPU_STALL_DETECTOR_RUNNABLE kernel config parameters. The RCU_CPU_STALL_TIMEOUT parameter remains to allow the timeout to be tuned and the RCU_CPU_STALL_VERBOSE parameter remains to allow task-stall information to be suppressed if desired. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
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- 04 May, 2011 4 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6Linus Torvalds authored
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: drm/radeon/kms: fix gart setup on fusion parts (v2) drm: Send pending vblank events before disabling vblank. drm/radeon: fix regression on atom cards with hardcoded EDID record. drm/radeon/kms: add some new pci ids
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Alex Deucher authored
Out of the entire GART/VM subsystem, the hw designers changed the location of 3 regs. v2: airlied: add parameter for userspace to work from. Signed-off-by: Alex Deucher <alexdeucher@gmail.com> Signed-off-by: Jerome Glisse <jglisse@redhat.com> Cc: stable@kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
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Christopher James Halse Rogers authored
This is the least-bad behaviour. It means that we signal the vblank event before it actually happens, but since we're disabling vblanks there's no guarantee that it will *ever* happen otherwise. This prevents GL applications which use WaitMSC from hanging indefinitely. Signed-off-by: Christopher James Halse Rogers <christopher.halse.rogers@canonical.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
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- 03 May, 2011 8 commits
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Dave Airlie authored
Since fafcf94e introduced an edid size, it seems to have broken this path. This manifest as oops on T500 Lenovo laptops with dual graphics primarily. Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33812 cc: stable@kernel.org Reviewed-by: Alex Deucher <alexdeucher@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
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Alex Deucher authored
Signed-off-by: Alex Deucher <alexdeucher@gmail.com> Cc: stable@kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
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Linus Torvalds authored
In particular, s_freeing_list needs to be initialized early, since it is used on some of the error paths when mounts fail. The mapping inode, for example, would be initialized and then free'd on an error path before s_freeing_list was initialized, but the inode drop operation needs the s_freeing_list to be set up. Normally you'd never see this, because not only is logfs fairly rare, but a successful mount will never have any issues. Reported-by: werner <w.landgraf@ru.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xenLinus Torvalds authored
* 'stable/bug-fixes-for-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: mask_rw_pte mark RO all pagetable pages up to pgt_buf_top xen/mmu: Add workaround "x86-64, mm: Put early page table high"
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git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmcLinus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc: mmc: sdhci: Check mrq != NULL in sdhci_tasklet_finish mmc: sdhci: Check mrq->cmd in sdhci_tasklet_finish mmc: tmio: fix .set_ios(MMC_POWER_UP) handling mmc: fix a race between card-detect rescan and clock-gate work instances mmc: omap: Fix possible NULL pointer deref mmc: core: mmc_add_card(): fix missing break in switch statement mmc: sdhci-pci: Fix error case in sdhci_pci_probe_slot()
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Linus Torvalds authored
Merge branches 'x86-fixes-for-linus' and 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, reboot: Fix relocations in reboot_32.S x86, NUMA: Fix empty memblk detection in numa_cleanup_meminfo() x86, AMD: Fix APIC timer erratum 400 affecting K8 Rev.A-E processors * 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Fix typo CONFIG_GENIRC_IRQ_SHOW_LEVEL
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git://git.kernel.org/pub/scm/linux/kernel/git/dtor/inputLinus Torvalds authored
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: wm831x-ts - move BTN_TOUCH reporting to data transfer Input: wm831x-ts - allow IRQ flags to be specified Input: wm831x-ts - fix races with IRQ management
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds authored
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (47 commits) sysctl: net: call unregister_net_sysctl_table where needed Revert: veth: remove unneeded ifname code from veth_newlink() smsc95xx: fix reset check tg3: Fix failure to enable WoL by default when possible networking: inappropriate ioctl operation should return ENOTTY amd8111e: trivial typo spelling: Negotitate -> Negotiate ipv4: don't spam dmesg with "Using LC-trie" messages af_unix: Only allow recv on connected seqpacket sockets. mii: add support of pause frames in mii_get_an net: ftmac100: fix scheduling while atomic during PHY link status change usbnet: Transfer of maintainership usbnet: add support for some Huawei modems with cdc-ether ports bnx2: cancel timer on device removal iwl4965: fix "Received BA when not expected" iwlagn: fix "Received BA when not expected" dsa/mv88e6131: fix unknown multicast/broadcast forwarding on mv88e6085 usbnet: Resubmit interrupt URB if device is open iwl4965: fix "TX Power requested while scanning" iwlegacy: led stay solid on when no traffic b43: trivial: update module info about ucode16_mimo firmware ...
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- 02 May, 2011 8 commits
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Lucian Adrian Grijincu authored
ctl_table_headers registered with register_net_sysctl_table should have been unregistered with the equivalent unregister_net_sysctl_table Signed-off-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Jiri Pirko authored
84c49d8c ("veth: remove unneeded ifname code from veth_newlink()") caused regression on veth creation. This patch reverts the original one. Reported-by: Michał Mirosław <mirqus@gmail.com> Signed-off-by: Jiri Pirko <jpirko@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Rabin Vincent authored
The reset loop check should check the MII_BMCR register value for BMCR_RESET rather than for MII_BMCR (the register address, which also happens to be zero). Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: David S. Miller <davem@davemloft.net>
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Rafael J. Wysocki authored
tg3 is supposed to enable WoL by default on adapters which support that, but it fails to do so unless the adapter's /sys/devices/.../power/wakeup file contains 'enabled' during the initialization of the adapter. Fix that by making tg3 use device_set_wakeup_enable() to enable wakeup automatically whenever WoL should be enabled by default. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
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Lifeng Sun authored
ioctl() calls against a socket with an inappropriate ioctl operation are incorrectly returning EINVAL rather than ENOTTY: [ENOTTY] Inappropriate I/O control operation. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=33992Signed-off-by: Lifeng Sun <lifongsun@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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H. Peter Anvin authored
The use of base for %ebx in this file is arbitrary, *except* that we also use it to compute the real-mode segment. Therefore, make it so that r_base really is the true address to which %ebx points. This resolves kernel bugzilla 33302. Reported-and-tested-by: Alexey Zaytsev <alexey.zaytsev@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/n/tip-08os5wi3yq1no0y4i5m4z7he@git.kernel.org
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Joe Perches authored
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Stefano Stabellini authored
mask_rw_pte is currently checking if a pfn is a pagetable page if it falls in the range pgt_buf_start - pgt_buf_end but that is incorrect because pgt_buf_end is a moving target: pgt_buf_top is the real boundary. Acked-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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