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2011-05-05rcu: Update RCU's trace.txt documentation for new formatPaul E. McKenney
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>
2011-05-05rcu: Add boosting to TREE_PREEMPT_RCU tracingPaul E. McKenney
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>
2011-05-05rcu: eliminate unused boosting statisticsPaul E. McKenney
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>
2011-05-05rcu: avoid hammering sched with yet another bound RT kthreadPaul E. McKenney
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>
2011-05-05rcu: put per-CPU kthread at non-RT priority during CPU hotplug operationsPaul E. McKenney
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>
2011-05-05rcu: Force per-rcu_node kthreads off of the outgoing CPUPaul E. McKenney
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>
2011-05-05rcu: priority boosting for TREE_PREEMPT_RCUPaul E. McKenney
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>
2011-05-05rcu: move TREE_RCU from softirq to kthreadPaul E. McKenney
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>
2011-05-05rcu: merge TREE_PREEPT_RCU blocked_tasks[] listsPaul E. McKenney
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>
2011-05-05rcu: Decrease memory-barrier usage based on semi-formal proofPaul E. McKenney
Commit d09b62d 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>
2011-05-05rcu: Remove conditional compilation for RCU CPU stall warningsPaul E. McKenney
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>
2011-05-06Merge branch 'master' of ↵Ingo Molnar
ssh://master.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into perf/urgent
2011-05-05Merge branch 'for-linus' of git://github.com/at91linux/linux-2.6-at91Linus Torvalds
* 'for-linus' of git://github.com/at91linux/linux-2.6-at91: at91: Add ARCH_ID and basic cpu macros definition for 5series chips family. arm: at91: fix compiler warning for eb01 board build arm: at91: minimal defconfig for at91x40 SoC ARM: at91: AT91CAP9 has a macb device
2011-05-05can: fix SJA1000 dlc for RTR packetsKurt Van Dijck
RTR frames do have a valid data length code on CAN. The driver for SJA1000 did not handle that situation properly. Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-05usbnet: runtime pm: fix out of memoryMing Lei
This patch makes use of the EVENT_DEV_OPEN flag introduced recently to fix one out of memory issue, which can be reproduced on omap3/4 based pandaboard/beagle XM easily with steps below: - enable runtime pm echo auto > /sys/devices/platform/usbhs-omap.0/ehci-omap.0/usb1/1-1/1-1.1/power/control - ifconfig eth0 up - then out of memroy happened, see [1] for kernel message. Follows my analysis: - 'ifconfig eth0 up' brings eth0 out of suspend, and usbnet_resume is called to schedule dev->bh, then rx urbs are submited to prepare for recieving data; - some usbnet devices will produce garbage rx packets flood if info->reset is not called in usbnet_open. - so there is no enough chances for usbnet_bh to handle and release recieved skb buffers since many rx interrupts consumes cpu, so out of memory for atomic allocation in rx_submit happened. This patch fixes the issue by simply not allowing schedule of usbnet_bh until device is opened. [1], dmesg [ 234.712005] smsc95xx 1-1.1:1.0: rpm_resume flags 0x4 [ 234.712066] usb 1-1.1: rpm_resume flags 0x0 [ 234.712066] usb 1-1: rpm_resume flags 0x0 [ 234.712097] usb usb1: rpm_resume flags 0x0 [ 234.712127] usb usb1: usb auto-resume [ 234.712158] ehci-omap ehci-omap.0: resume root hub [ 234.754028] hub 1-0:1.0: hub_resume [ 234.754821] hub 1-0:1.0: port 1: status 0507 change 0000 [ 234.756011] hub 1-0:1.0: state 7 ports 3 chg 0000 evt 0000 [ 234.756042] hub 1-0:1.0: rpm_resume flags 0x4 [ 234.756072] usb usb1: rpm_resume flags 0x0 [ 234.756164] usb usb1: rpm_resume returns 1 [ 234.756195] hub 1-0:1.0: rpm_resume returns 0 [ 234.756195] hub 1-0:1.0: rpm_suspend flags 0x4 [ 234.756225] hub 1-0:1.0: rpm_suspend returns 0 [ 234.756256] usb usb1: rpm_resume returns 0 [ 234.757141] usb 1-1: usb auto-resume [ 234.793151] ehci-omap ehci-omap.0: GetStatus port:1 status 001005 0 ACK POWER sig=se0 PE CONNECT [ 234.816558] usb 1-1: finish resume [ 234.817871] hub 1-1:1.0: hub_resume [ 234.818420] hub 1-1:1.0: port 1: status 0507 change 0000 [ 234.820495] ehci-omap ehci-omap.0: reused qh eec50220 schedule [ 234.820495] usb 1-1: link qh256-0001/eec50220 start 1 [1/0 us] [ 234.820587] usb 1-1: rpm_resume returns 0 [ 234.820800] hub 1-1:1.0: state 7 ports 5 chg 0000 evt 0000 [ 234.820800] hub 1-1:1.0: rpm_resume flags 0x4 [ 234.820831] hub 1-1:1.0: rpm_resume returns 0 [ 234.820861] hub 1-1:1.0: rpm_suspend flags 0x4 [ 234.820861] hub 1-1:1.0: rpm_suspend returns 0 [ 234.821777] usb 1-1.1: usb auto-resume [ 234.868591] hub 1-1:1.0: state 7 ports 5 chg 0000 evt 0002 [ 234.868591] hub 1-1:1.0: rpm_resume flags 0x4 [ 234.868621] hub 1-1:1.0: rpm_resume returns 0 [ 234.868652] hub 1-1:1.0: rpm_suspend flags 0x4 [ 234.868652] hub 1-1:1.0: rpm_suspend returns 0 [ 234.879486] usb 1-1.1: finish resume [ 234.880279] usb 1-1.1: rpm_resume returns 0 [ 234.880310] smsc95xx 1-1.1:1.0: rpm_resume returns 0 [ 238.880187] ksoftirqd/0: page allocation failure. order:0, mode:0x20 [ 238.880218] Backtrace: [ 238.880249] [<c01b9800>] (dump_backtrace+0x0/0xf8) from [<c065e1dc>] (dump_stack+0x18/0x1c) [ 238.880249] r6:00000000 r5:00000000 r4:00000020 r3:00000002 [ 238.880310] [<c065e1c4>] (dump_stack+0x0/0x1c) from [<c026ece4>] (__alloc_pages_nodemask+0x620/0x724) [ 238.880340] [<c026e6c4>] (__alloc_pages_nodemask+0x0/0x724) from [<c02986d4>] (kmem_getpages.clone.34+0x34/0xc8) [ 238.880371] [<c02986a0>] (kmem_getpages.clone.34+0x0/0xc8) from [<c02988f8>] (cache_grow.clone.42+0x84/0x154) [ 238.880371] r6:ef871aa4 r5:ef871a80 r4:ef81fd40 r3:00000020 [ 238.880401] [<c0298874>] (cache_grow.clone.42+0x0/0x154) from [<c0298b64>] (cache_alloc_refill+0x19c/0x1f0) [ 238.880432] [<c02989c8>] (cache_alloc_refill+0x0/0x1f0) from [<c0299804>] (kmem_cache_alloc+0x90/0x190) [ 238.880462] [<c0299774>] (kmem_cache_alloc+0x0/0x190) from [<c052e260>] (__alloc_skb+0x34/0xe8) [ 238.880493] [<c052e22c>] (__alloc_skb+0x0/0xe8) from [<bf0509f4>] (rx_submit+0x2c/0x1d4 [usbnet]) [ 238.880523] [<bf0509c8>] (rx_submit+0x0/0x1d4 [usbnet]) from [<bf050d38>] (rx_complete+0x19c/0x1b0 [usbnet]) [ 238.880737] [<bf050b9c>] (rx_complete+0x0/0x1b0 [usbnet]) from [<bf006fd0>] (usb_hcd_giveback_urb+0xa8/0xf4 [usbcore]) [ 238.880737] r8:eeeced34 r7:eeecec00 r6:eeecec00 r5:00000000 r4:eec2dd20 [ 238.880767] r3:bf050b9c [ 238.880859] [<bf006f28>] (usb_hcd_giveback_urb+0x0/0xf4 [usbcore]) from [<bf03c8f8>] (ehci_urb_done+0xb0/0xbc [ehci_hcd]) [ 238.880859] r6:00000000 r5:eec2dd20 r4:eeeced44 r3:eec2dd34 [ 238.880920] [<bf03c848>] (ehci_urb_done+0x0/0xbc [ehci_hcd]) from [<bf040204>] (qh_completions+0x308/0x3bc [ehci_hcd]) [ 238.880920] r7:00000000 r6:eeda21a0 r5:ffdfe3c0 r4:eeda21ac [ 238.880981] [<bf03fefc>] (qh_completions+0x0/0x3bc [ehci_hcd]) from [<bf040ef8>] (scan_async+0xb0/0x16c [ehci_hcd]) [ 238.881011] [<bf040e48>] (scan_async+0x0/0x16c [ehci_hcd]) from [<bf040fec>] (ehci_work+0x38/0x90 [ehci_hcd]) [ 238.881042] [<bf040fb4>] (ehci_work+0x0/0x90 [ehci_hcd]) from [<bf042940>] (ehci_irq+0x300/0x34c [ehci_hcd]) [ 238.881072] r4:eeeced34 r3:00000001 [ 238.881134] [<bf042640>] (ehci_irq+0x0/0x34c [ehci_hcd]) from [<bf006828>] (usb_hcd_irq+0x40/0xac [usbcore]) [ 238.881195] [<bf0067e8>] (usb_hcd_irq+0x0/0xac [usbcore]) from [<c0239764>] (handle_irq_event_percpu+0xb8/0x240) [ 238.881225] r6:eec504e0 r5:0000006d r4:eec504e0 r3:bf0067e8 [ 238.881256] [<c02396ac>] (handle_irq_event_percpu+0x0/0x240) from [<c0239930>] (handle_irq_event+0x44/0x64) [ 238.881256] [<c02398ec>] (handle_irq_event+0x0/0x64) from [<c023bbd0>] (handle_level_irq+0xe0/0x114) [ 238.881286] r6:0000006d r5:c080c14c r4:c080c100 r3:00020000 [ 238.881317] [<c023baf0>] (handle_level_irq+0x0/0x114) from [<c01ab090>] (asm_do_IRQ+0x90/0xd0) [ 238.881317] r5:00000000 r4:0000006d [ 238.881347] [<c01ab000>] (asm_do_IRQ+0x0/0xd0) from [<c06624d0>] (__irq_svc+0x50/0x134) [ 238.881378] Exception stack(0xef837e20 to 0xef837e68) [ 238.881378] 7e20: 00000001 00185610 016cc000 c00490c0 eb380000 ef800540 00000020 00004ae0 [ 238.881408] 7e40: 00000020 bf0509f4 60000013 ef837e9c ef837e40 ef837e68 c0226f0c c0298ca0 [ 238.881408] 7e60: 20000013 ffffffff [ 238.881408] r5:fa240100 r4:ffffffff [ 238.881439] [<c0298bb8>] (__kmalloc_track_caller+0x0/0x1d0) from [<c052e284>] (__alloc_skb+0x58/0xe8) [ 238.881469] [<c052e22c>] (__alloc_skb+0x0/0xe8) from [<bf0509f4>] (rx_submit+0x2c/0x1d4 [usbnet]) [ 238.881500] [<bf0509c8>] (rx_submit+0x0/0x1d4 [usbnet]) from [<bf0513d8>] (usbnet_bh+0x1b4/0x250 [usbnet]) [ 238.881530] [<bf051224>] (usbnet_bh+0x0/0x250 [usbnet]) from [<c01f912c>] (tasklet_action+0xb0/0x1f8) [ 238.881530] r6:00000000 r5:ef9757f0 r4:ef9757ec r3:bf051224 [ 238.881561] [<c01f907c>] (tasklet_action+0x0/0x1f8) from [<c01f97ac>] (__do_softirq+0x140/0x290) [ 238.881561] r8:00000006 r7:00000101 r6:00000000 r5:c0806098 r4:00000001 [ 238.881591] r3:c01f907c [ 238.881622] [<c01f966c>] (__do_softirq+0x0/0x290) from [<c01f99cc>] (run_ksoftirqd+0xd0/0x1f4) [ 238.881622] [<c01f98fc>] (run_ksoftirqd+0x0/0x1f4) from [<c02113b0>] (kthread+0x90/0x98) [ 238.881652] r7:00000013 r6:c01f98fc r5:00000000 r4:ef831efc [ 238.881683] [<c0211320>] (kthread+0x0/0x98) from [<c01f62f4>] (do_exit+0x0/0x374) [ 238.881713] r6:c01f62f4 r5:c0211320 r4:ef831efc [ 238.881713] Mem-info: [ 238.881744] Normal per-cpu: [ 238.881744] CPU 0: hi: 186, btch: 31 usd: 38 [ 238.881744] CPU 1: hi: 186, btch: 31 usd: 169 [ 238.881774] HighMem per-cpu: [ 238.881774] CPU 0: hi: 90, btch: 15 usd: 66 [ 238.881774] CPU 1: hi: 90, btch: 15 usd: 86 [ 238.881805] active_anon:544 inactive_anon:71 isolated_anon:0 [ 238.881805] active_file:926 inactive_file:2538 isolated_file:0 [ 238.881805] unevictable:0 dirty:10 writeback:0 unstable:0 [ 238.881805] free:57782 slab_reclaimable:864 slab_unreclaimable:186898 [ 238.881805] mapped:632 shmem:144 pagetables:50 bounce:0 [ 238.881835] Normal free:1328kB min:3532kB low:4412kB high:5296kB active_anon:0kB inactive_anon:0kB active_file:880kB inactive_file:848kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:780288kB mlocked:0kB dirty:36kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:3456kB slab_unreclaimable:747592kB kernel_stack:392kB pagetables:200kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no [ 238.881866] lowmem_reserve[]: 0 1904 1904 [ 238.881896] HighMem free:229800kB min:236kB low:508kB high:784kB active_anon:2176kB inactive_anon:284kB active_file:2824kB inactive_file:9304kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:243712kB mlocked:0kB dirty:4kB writeback:0kB mapped:2528kB shmem:576kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no [ 238.881927] lowmem_reserve[]: 0 0 0 [ 238.881958] Normal: 0*4kB 4*8kB 6*16kB 0*32kB 1*64kB 1*128kB 0*256kB 2*512kB 0*1024kB 0*2048kB 0*4096kB = 1344kB [ 238.882019] HighMem: 6*4kB 2*8kB 4*16kB 4*32kB 1*64kB 1*128kB 0*256kB 2*512kB 3*1024kB 0*2048kB 55*4096kB = 229800kB [ 238.882080] 3610 total pagecache pages [ 238.882080] 0 pages in swap cache [ 238.882080] Swap cache stats: add 0, delete 0, find 0/0 [ 238.882110] Free swap = 0kB [ 238.882110] Total swap = 0kB [ 238.933776] 262144 pages of RAM [ 238.933776] 58240 free pages [ 238.933776] 10503 reserved pages [ 238.933776] 187773 slab pages [ 238.933807] 2475 pages shared [ 238.933807] 0 pages swap cached Signed-off-by: Ming Lei <tom.leiming@gmail.com> Acked-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-05Input: ads7846 - remove unused variable from struct ads7845_ser_reqAlexander Stein
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2011-05-05Input: ads7846 - make transfer buffers DMA safeAlexander Stein
req.sample needs its own cacheline otherwise accessing req.msg fetches it in again. Note: This effect doesn't occur if the underlying SPI driver doesn't use DMA at all. Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2011-05-05clocksource: Install completely before selectingjohn stultz
Christian Hoffmann reported that the command line clocksource override with acpi_pm timer fails: Kernel command line: <SNIP> clocksource=acpi_pm hpet clockevent registered Switching to clocksource hpet Override clocksource acpi_pm is not HRT compatible. Cannot switch while in HRT/NOHZ mode. The watchdog code is what enables CLOCK_SOURCE_VALID_FOR_HRES, but we actually end up selecting the clocksource before we enqueue it into the watchdog list, so that's why we see the warning and fail to switch to acpi_pm timer as requested. That's particularly bad when we want to debug timekeeping related problems in early boot. Put the selection call last. Reported-by: Christian Hoffmann <email@christianhoffmann.info> Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: stable@kernel.org # 32... Link: http://lkml.kernel.org/r/%3C1304558210.2943.24.camel%40work-vm%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-05-04VM: skip the stack guard page lookup in get_user_pages only for mlockLinus Torvalds
The logic in __get_user_pages() used to skip the stack guard page lookup whenever the caller wasn't interested in seeing what the actual page was. But Michel Lespinasse points out that there are cases where we don't care about the physical page itself (so 'pages' may be NULL), but do want to make sure a page is mapped into the virtual address space. So using the existence of the "pages" array as an indication of whether to look up the guard page or not isn't actually so great, and we really should just use the FOLL_MLOCK bit. But because that bit was only set for the VM_LOCKED case (and not all vma's necessarily have it, even for mlock()), we couldn't do that originally. Fix that by moving the VM_LOCKED check deeper into the call-chain, which actually simplifies many things. Now mlock() gets simpler, and we can also check for FOLL_MLOCK in __get_user_pages() and the code ends up much more straightforward. Reported-and-reviewed-by: Michel Lespinasse <walken@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-04Merge branch 'staging-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6 * 'staging-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: staging: Remove a warning for drivers/staging/wlan-ng/cfg80211.c staging: intel_sst: intelmid needs delay.h staging: solo6x10: add select SND_PCM to fix build error staging: usbip: vhci: fix oops on subsequent attach staging: ft1000: Remove unnecessary EXPORT_SYMBOLs staging: rts_pstor: use #ifdef instead of #if staging: rts_pstor: Add <linux/vmalloc.h> staging: gma500: Depend on X86 staging: olpc: Add <linux/delay.h>
2011-05-04Merge branch 'usb-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 * 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: xHCI: Clear PLC in xhci_bus_resume() USB: fix regression in usbip by setting has_tt flag usb/isp1760: Report correct urb status after unlink omap:usb: add regulator support for EHCI mfd: Fix usbhs_enable error handling usb: musb: gadget: Fix out-of-sync runtime pm calls usb: musb: omap2430: Fix retention idle on musb peripheral only boards
2011-05-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: ceph: do not call __mark_dirty_inode under i_lock libceph: fix ceph_osdc_alloc_request error checks ceph: handle ceph_osdc_new_request failure in ceph_writepages_start libceph: fix ceph_msg_new error path ceph: use ihold() when i_lock is held
2011-05-04Merge branch 'v4l_for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: [media] ngene: Fix CI data transfer regression Fix CI data transfer regression introduced by previous cleanup. [media] v4l: make sure drivers supply a zeroed struct v4l2_subdev [media] Missing frontend config for LME DM04/QQBOX [media] rc_core: avoid kernel oops when rmmod saa7134 [media] imon: add conditional locking in change_protocol [media] rc: show RC_TYPE_OTHER in sysfs [media] ite-cir: modular build on ppc requires delay.h include [media] mceusb: add Dell transceiver ID
2011-05-04Merge branch 'fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: firewire: Fix for broken configrom updates in quick succession
2011-05-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: flex_arrays: allow zero length flex arrays flex_array: flex_array_prealloc takes a number of elements, not an end SELinux: pass last path component in may_create
2011-05-04slub: Fix the lockless code on 32-bit platforms with no 64-bit cmpxchgThomas Gleixner
The SLUB allocator use of the cmpxchg_double logic was wrong: it actually needs the irq-safe one. That happens automatically when we use the native unlocked 'cmpxchg8b' instruction, but when compiling the kernel for older x86 CPUs that do not support that instruction, we fall back to the generic emulation code. And if you don't specify that you want the irq-safe version, the generic code ends up just open-coding the cmpxchg8b equivalent without any protection against interrupts or preemption. Which definitely doesn't work for SLUB. This was reported by Werner Landgraf <w.landgraf@ru.ru>, who saw instability with his distro-kernel that was compiled to support pretty much everything under the sun. Most big Linux distributions tend to compile for PPro and later, and would never have noticed this problem. This also fixes the prototypes for the irqsafe cmpxchg_double functions to use 'bool' like they should. [ Btw, that whole "generic code defaults to no protection" design just sounds stupid - if the code needs no protection, there is no reason to use "cmpxchg_double" to begin with. So we should probably just remove the unprotected version entirely as pointless. - Linus ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reported-and-tested-by: werner <w.landgraf@ru.ru> Acked-and-tested-by: Ingo Molnar <mingo@elte.hu> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1105041539050.3005@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-04net: ip_expire() must revalidate routeEric Dumazet
Commit 4a94445c9a5c (net: Use ip_route_input_noref() in input path) added a bug in IP defragmentation handling, in case timeout is fired. When a frame is defragmented, we use last skb dst field when building final skb. Its dst is valid, since we are in rcu read section. But if a timeout occurs, we take first queued fragment to build one ICMP TIME EXCEEDED message. Problem is all queued skb have weak dst pointers, since we escaped RCU critical section after their queueing. icmp_send() might dereference a now freed (and possibly reused) part of memory. Calling skb_dst_drop() and ip_route_input_noref() to revalidate route is the only possible choice. Reported-by: Denys Fedoryshchenko <denys@visp.net.lb> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-04ceph: do not call __mark_dirty_inode under i_lockSage Weil
The __mark_dirty_inode helper now takes i_lock as of 250df6ed. Fix the one ceph callers that held i_lock (__ceph_mark_dirty_caps) to return the flags value so that the callers can do it outside of i_lock. Signed-off-by: Sage Weil <sage@newdream.net>
2011-05-04[media] V4L: soc-camera: regression fix: calculate .sizeimage in soc_camera.cSergio Aguirre
A recent patch has given individual soc-camera host drivers a possibility to calculate .sizeimage and .bytesperline pixel format fields internally, however, some drivers relied on the core calculating these values for them, following a default algorithm. This patch restores the default calculation for such drivers. Based on initial patch by Guennadi Liakhovetski, found here: http://www.spinics.net/lists/linux-media/msg31282.html Except that this covers try_fmt aswell. Signed-off-by: Sergio Aguirre <saaguirre@ti.com> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-05-04[media] v4l2-subdev: fix broken subdev control enumerationHans Verkuil
The v4l2_subdev_* functions are meant for older V4L2 drivers that do not use the control framework yet. These functions should not be used by subdev_do_ioctl. Most of those backwards compatibility functions are just stubs, but commit 87a0c94ce616b231f3c0bd09d7dbd39d43b0557a actually changed the behavior of v4l2_subdev_queryctrl, so calling that one from subdev_do_ioctl broke the control enumeration in subdev nodes. The fix is simply not to use those compatibility functions in v4l2-subdev.c. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-05-04drm/i915/dp: Be paranoid in case we disable a DP before it is attachedChris Wilson
Given that the hardware may be left in a random condition by the BIOS, it is conceivable that we then attempt to clear the DP_PIPEB_SELECT bit without us ever enabling/attaching the DP encoder to a pipe. Thus causing a NULL deference when we attempt to wait for a vblank on that crtc. Reported-and-tested-by: Bryan Christ <bryan.christ@gmail.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=36314 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=36456 Reported-and-tested-by: Bo Wang <bo.b.wang@intel.com> Cc: stable@kernel.org Signed-off-by: Keith Packard <keithp@keithp.com>
2011-05-04drm/i915: Release object along create user fb error pathChris Wilson
Reported-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: stable@kernel.org Signed-off-by: Keith Packard <keithp@keithp.com>
2011-05-04[media] Fix cx88 remote control inputLawrence Rust
In the IR interrupt handler of cx88-input.c there's a 32-bit multiply overflow which causes IR pulse durations to be incorrectly calculated. This is a regression caused by commit 2997137be8eba. Cc: stable@kernel.org Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-05-04[media] v4l: Release module if subdev registration failsLaurent Pinchart
If v4l2_device_register_subdev() fails, the reference to the subdev module taken by the function isn't released. Fix this. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: stable@kernel.org Acked-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-05-04Merge branch 'perf/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/urgent
2011-05-04[CPUFREQ] remove redundant sprintf from request_module call.Kees Cook
Since format string handling is part of request_module, there is no need to construct the module name. As such, drop the redundant sprintf and heap usage. Signed-off-by: Kees Cook <kees.cook@canonical.com> Signed-off-by: Dave Jones <davej@redhat.com>
2011-05-04[CPUFREQ] cpufreq_stats.c: Fixed brace coding style issueKarthigan Srinivasan
Fixed brace coding style issue. Signed-off-by: Karthigan Srinivasan <karthigan.srinivasan@hp.com> Signed-off-by: Dave Jones <davej@redhat.com>
2011-05-04[CPUFREQ] Fix memory leak in cpufreq_statsteven finney
When a CPU is taken offline in an SMP system, cpufreq_remove_dev() nulls out the per-cpu policy before cpufreq_stats_free_table() can make use of it. cpufreq_stats_free_table() then skips the call to sysfs_remove_group(), leaving about 100 bytes of sysfs-related memory unclaimed each time a CPU-removal occurs. Break up cpu_stats_free_table into sysfs and table portions, and call the sysfs portion early. Signed-off-by: Steven Finney <steven.finney@palm.com> Signed-off-by: Dave Jones <davej@redhat.com> Cc: stable@kernel.org
2011-05-04[CPUFREQ] cpufreq.h: Fix some checkpatch.pl coding style issues.Thiago Farina
Before: $ scripts/checkpatch.pl --file --terse include/linux/cpufreq.h total: 14 errors, 11 warnings, 419 lines checked After: $ scripts/checkpatch.pl --file --terse include/linux/cpufreq.h total: 2 errors, 4 warnings, 422 lines checked Signed-off-by: Thiago Farina <tfransosi@gmail.com> Signed-off-by: Dave Jones <davej@redhat.com>
2011-05-04[CPUFREQ] use dynamic debug instead of custom infrastructureDominik Brodowski
With dynamic debug having gained the capability to report debug messages also during the boot process, it offers a far superior interface for debug messages than the custom cpufreq infrastructure. As a first step, remove the old cpufreq_debug_printk() function and replace it with a call to the generic pr_debug() function. How can dynamic debug be used on cpufreq? You need a kernel which has CONFIG_DYNAMIC_DEBUG enabled. To enabled debugging during runtime, mount debugfs and $ echo -n 'module cpufreq +p' > /sys/kernel/debug/dynamic_debug/control for debugging the complete "cpufreq" module. To achieve the same goal during boot, append ddebug_query="module cpufreq +p" as a boot parameter to the kernel of your choice. For more detailled instructions, please see Documentation/dynamic-debug-howto.txt Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Dave Jones <davej@redhat.com>
2011-05-04[CPUFREQ] CPU hotplug, re-create sysfs directory and symlinksJacob Shin
When we discover CPUs that are affected by each other's frequency/voltage transitions, the first CPU gets a sysfs directory created, and rest of the siblings get symlinks. Currently, when we hotplug off only the first CPU, all of the symlinks and the sysfs directory gets removed. Even though rest of the siblings are still online and functional, they are orphaned, and no longer governed by cpufreq. This patch, given the above scenario, creates a sysfs directory for the first sibling and symlinks for the rest of the siblings. Please note the recursive call, it was rather too ugly to roll it out. And the removal of redundant NULL setting (it is already taken care of near the top of the function). Signed-off-by: Jacob Shin <jacob.shin@amd.com> Acked-by: Mark Langsdorf <mark.langsdorf@amd.com> Reviewed-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com> Cc: stable@kernel.org
2011-05-04[CPUFREQ] Fix _OSC UUID in pcc-cpufreqNaga Chumbalkar
UUID needs to be written out the way it is described in Sec 18.5.124 of ACPI 4.0a Specification. Platform firmware's use of this UUID/_OSC is optional, which is why we didn't notice this bug earlier. Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com> Signed-off-by: Dave Jones <davej@redhat.com> Cc: stable@kernel.org
2011-05-04sched: Remove unused 'this_best_prio arg' from balance_tasks()Vladimir Davydov
It's passed across multiple functions but is never really used, so remove it. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1304447467-29200-1-git-send-email-vdavydov@parallels.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-04perf events: Clean up definitions and initializers, update copyrightsIngo Molnar
Fix a few inconsistent style bits that were added over the past few months. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-yv4hwf9yhnzoada8pcpb3a97@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-03Linux 2.6.39-rc6v2.6.39-rc6Linus Torvalds
2011-05-04Merge branch 'for-linus' of git://git.infradead.org/users/eparis/selinux ↵James Morris
into for-linus
2011-05-03Merge branch 'drm-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 * '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
2011-05-04drm/radeon/kms: fix gart setup on fusion parts (v2)Alex Deucher
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>
2011-05-04drm: Send pending vblank events before disabling vblank.Christopher James Halse Rogers
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>
2011-05-04drm/radeon: fix regression on atom cards with hardcoded EDID record.Dave Airlie
Since fafcf94e2b5732d1e13b440291c53115d2b172e9 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>