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2011-05-17Merge branch 'gart/rename' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into core/iommu
2011-05-17scsi: remove performance regression due to async queue runJens Axboe
Commit c21e6beb removed our queue request_fn re-enter protection, and defaulted to always running the queues from kblockd to be safe. This was a known potential slow down, but should be safe. Unfortunately this is causing big performance regressions for some, so we need to improve this logic. Looking into the details of the re-enter, the real issue is on requeue of requests. Requeue of requests upon seeing a BUSY condition from the device ends up re-running the queue, causing traces like this: scsi_request_fn() scsi_dispatch_cmd() scsi_queue_insert() __scsi_queue_insert() scsi_run_queue() scsi_request_fn() ... potentially causing the issue we want to avoid. So special case the requeue re-run of the queue, but improve it to offload the entire run of local queue and starved queue from a single workqueue callback. This is a lot better than potentially kicking off a workqueue run for each device seen. This also fixes the issue of the local device going into recursion, since the above mentioned commit never moved that queue run out of line. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-05-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: net: Change netdev_fix_features messages loglevel vmxnet3: Fix inconsistent LRO state after initialization sfc: Fix oops in register dump after mapping change IPVS: fix netns if reading ip_vs_* procfs entries bridge: fix forwarding of IPv6
2011-05-16Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc: Revert "mmc: fix a race between card-detect rescan and clock-gate work instances"
2011-05-16mm: fix kernel-doc warning in page_alloc.cRandy Dunlap
Fix new kernel-doc warning in mm/page_alloc.c: Warning(mm/page_alloc.c:2370): No description found for parameter 'nid' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-16PCI: Clear bridge resource flags if requested size is 0Yinghai Lu
During pci remove/rescan testing found: pci 0000:c0:03.0: PCI bridge to [bus c4-c9] pci 0000:c0:03.0: bridge window [io 0x1000-0x0fff] pci 0000:c0:03.0: bridge window [mem 0xf0000000-0xf00fffff] pci 0000:c0:03.0: bridge window [mem 0xfc180000000-0xfc197ffffff 64bit pref] pci 0000:c0:03.0: device not available (can't reserve [io 0x1000-0x0fff]) pci 0000:c0:03.0: Error enabling bridge (-22), continuing pci 0000:c0:03.0: enabling bus mastering pci 0000:c0:03.0: setting latency timer to 64 pcieport 0000:c0:03.0: device not available (can't reserve [io 0x1000-0x0fff]) pcieport: probe of 0000:c0:03.0 failed with error -22 This bug was caused by commit c8adf9a3e873 ("PCI: pre-allocate additional resources to devices only after successful allocation of essential resources.") After that commit, pci_hotplug_io_size is changed to additional_io_size from minium size. So it will not go through resource_size(res) != 0 path, and will not be reset. The root cause is: pci_bridge_check_ranges will set RESOURCE_IO flag for pci bridge, and later if children do not need IO resource. those bridge resources will not need to be allocated. but flags is still there. that will confuse the the pci_enable_bridges later. related code: static void assign_requested_resources_sorted(struct resource_list *head, struct resource_list_x *fail_head) { struct resource *res; struct resource_list *list; int idx; for (list = head->next; list; list = list->next) { res = list->res; idx = res - &list->dev->resource[0]; if (resource_size(res) && pci_assign_resource(list->dev, idx)) { ... reset_resource(res); } } } At last, We have to clear the flags in pbus_size_mem/io when requested size == 0 and !add_head. becasue this case it will not go through adjust_resources_sorted(). Just make size1 = size0 when !add_head. it will make flags get cleared. At the same time when requested size == 0, add_size != 0, will still have in head and add_list. because we do not clear the flags for it. After this, we will get right result: pci 0000:c0:03.0: PCI bridge to [bus c4-c9] pci 0000:c0:03.0: bridge window [io disabled] pci 0000:c0:03.0: bridge window [mem 0xf0000000-0xf00fffff] pci 0000:c0:03.0: bridge window [mem 0xfc180000000-0xfc197ffffff 64bit pref] pci 0000:c0:03.0: enabling bus mastering pci 0000:c0:03.0: setting latency timer to 64 pcieport 0000:c0:03.0: setting latency timer to 64 pcieport 0000:c0:03.0: irq 160 for MSI/MSI-X pcieport 0000:c0:03.0: Signaling PME through PCIe PME interrupt pci 0000:c4:00.0: Signaling PME through PCIe PME interrupt pcie_pme 0000:c0:03.0:pcie01: service driver pcie_pme loaded aer 0000:c0:03.0:pcie02: service driver aer loaded pciehp 0000:c0:03.0:pcie04: Hotplug Controller: v3: more simple fix. also fix one typo in pbus_size_mem Signed-off-by: Yinghai Lu <yinghai@kernel.org> Reviewed-by: Ram Pai <linuxram@us.ibm.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-16tick: Clear broadcast active bit when switching to oneshotThomas Gleixner
The first cpu which switches from periodic to oneshot mode switches also the broadcast device into oneshot mode. The broadcast device serves as a backup for per cpu timers which stop in deeper C-states. To avoid starvation of the cpus which might be in idle and depend on broadcast mode it marks the other cpus as broadcast active and sets the brodcast expiry value of those cpus to the next tick. The oneshot mode broadcast bit for the other cpus is sticky and gets only cleared when those cpus exit idle. If a cpu was not idle while the bit got set in consequence the bit prevents that the broadcast device is armed on behalf of that cpu when it enters idle for the first time after it switched to oneshot mode. In most cases that goes unnoticed as one of the other cpus has usually a timer pending which keeps the broadcast device armed with a short timeout. Now if the only cpu which has a short timer active has the bit set then the broadcast device will not be armed on behalf of that cpu and will fire way after the expected timer expiry. In the case of Christians bug report it took ~145 seconds which is about half of the wrap around time of HPET (the limit for that device) due to the fact that all other cpus had no timers armed which expired before the 145 seconds timeframe. The solution is simply to clear the broadcast active bit unconditionally when a cpu switches to oneshot mode after the first cpu switched the broadcast device over. It's not idle at that point otherwise it would not be executing that code. [ I fundamentally hate that broadcast crap. Why the heck thought some folks that when going into deep idle it's a brilliant concept to switch off the last device which brings the cpu back from that state? ] Thanks to Christian for providing all the valuable debug information! Reported-and-tested-by: Christian Hoffmann <email@christianhoffmann.info> Cc: John Stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/%3Calpine.LFD.2.02.1105161105170.3078%40ionos%3E Cc: stable@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-05-16x86, mm: Allow ZONE_DMA to be configurableDavid Rientjes
ZONE_DMA is unnecessary for a large number of machines that do not require less than 32-bit DMA addressing, e.g. ISA legacy DMA or PCI cards with a restricted DMA address mask. This patch allows users to disable ZONE_DMA for x86 if they know they will not be using such devices with their kernel. This prevents the VM from unnecessarily reserving a ratio of memory (defaulting to 1/256th of system capacity) with lowmem_reserve_ratio for such allocations when it will never be used. Signed-off-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1105161353560.4353@chino.kir.corp.google.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-16x86, cpu: Fix detection of Celeron Covington stepping A1 and B0Ondrej Zary
Steppings A1 and B0 of Celeron Covington are currently misdetected as Pentium II (Dixon). Fix it by removing the stepping check. [ hpa: this fixes this specific bug... the CPUID documentation specifies that the L2 cache size can disambiguate additional CPUs; this patch does not fix that. ] Signed-off-by: Ondrej Zary <linux@rainbow-software.org> Link: http://lkml.kernel.org/r/201105162138.15416.linux@rainbow-software.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-16net: Change netdev_fix_features messages loglevelMichał Mirosław
Those reduced to DEBUG can possibly be triggered by unprivileged processes and are nothing exceptional. Illegal checksum combinations can only be caused by driver bug, so promote those messages to WARN. Since GSO without SG will now only cause DEBUG message from netdev_fix_features(), remove the workaround from register_netdevice(). Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-16vmxnet3: Fix inconsistent LRO state after initializationThomas Jarosch
During initialization of vmxnet3, the state of LRO gets out of sync with netdev->features. This leads to very poor TCP performance in a IP forwarding setup and is hitting many VMware users. Simplified call sequence: 1. vmxnet3_declare_features() initializes "adapter->lro" to true. 2. The kernel automatically disables LRO if IP forwarding is enabled, so vmxnet3_set_flags() gets called. This also updates netdev->features. 3. Now vmxnet3_setup_driver_shared() is called. "adapter->lro" is still set to true and LRO gets enabled again, even though netdev->features shows it's disabled. Fix it by updating "adapter->lro", too. The private vmxnet3 adapter flags are scheduled for removal in net-next, see commit a0d2730c9571aeba793cb5d3009094ee1d8fda35 "net: vmxnet3: convert to hw_features". Patch applies to 2.6.37 / 2.6.38 and 2.6.39-rc6. Please CC: comments. Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-16sfc: Fix oops in register dump after mapping changeBen Hutchings
Commit 747df2258b1b9a2e25929ef496262c339c380009 ('sfc: Always map MCDI shared memory as uncacheable') introduced a separate mapping for the MCDI shared memory (MC_TREG_SMEM). This means we can no longer easily include it in the register dump. Since it is not particularly useful in debugging, substitute a recognisable dummy value. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-16ftrace/s390: mcount offset calculationMartin Schwidefsky
Do the mcount offset adjustment in the recordmcount.pl/recordmcount.[ch] at compile time and not in ftrace_call_adjust at run time. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/x86: mcount offset calculationMartin Schwidefsky
Do the mcount offset adjustment in the recordmcount.pl/recordmcount.[ch] at compile time and not in ftrace_call_adjust at run time. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/recordmcount: mcount address adjustmentMartin Schwidefsky
Introduce mcount_adjust{,_32,_64} to the C implementation of recordmcount analog to $mcount_adjust in the perl script. The adjustment is added to the address of the relocations against the mcount symbol. If this adjustment is done by recordmcount at compile time the ftrace_call_adjust function can be turned into a nop. Cc: John Reiser <jreiser@bitwagon.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/recordmcount: Add helper function get_sym_str_and_relp()Steven Rostedt
The code to get the symbol, string, and relp pointers in the two functions sift_rel_mcount() and nop_mcount() are identical and also non-trivial. Moving this duplicate code into a single helper function makes the code easier to read and more maintainable. Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023739.723658553@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/recordmcount: Remove duplicate code to find mcount symbolSteven Rostedt
The code in sift_rel_mcount() and nop_mcount() to get the mcount symbol number is identical. Replace the two locations with a call to a function that does the work. Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023739.488093407@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/x86: Do not trace .discard.text sectionSteven Rostedt
The section called .discard.text has tracing attached to it and is currently ignored by ftrace. But it does include a call to the mcount stub. Adding a notrace to the code keeps gcc from adding the useless mcount caller to it. Link: http://lkml.kernel.org/r/20110421023739.243651696@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace: Avoid recording mcount on .init sections directlySteven Rostedt
The init and exit sections should not be traced and adding a call to mcount to them is a waste of text and instruction cache. Have the macro section attributes include notrace to ignore these functions for tracing from the build. Link: http://lkml.kernel.org/r/20110421023738.953028219@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16kbuild/recordmcount: Add RECORDMCOUNT_WARN to warn about mcount callersSteven Rostedt
When mcount is called in a section that ftrace will not modify it into a nop, we want to warn about this. But not warn about this always. Now if the user builds the kernel with the option RECORDMCOUNT_WARN=1 then the build will warn about mcount callers that are ignored and will just waste execution time. Acked-by: Michal Marek <mmarek@suse.cz> Cc: linux-kbuild@vger.kernel.org Link: http://lkml.kernel.org/r/20110421023738.714956282@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/recordmcount: Add warning logic to warn on mcount not recordedSteven Rostedt
There's some sections that should not have mcount recorded and should not have modifications to the that code. But currently they waste some time by calling mcount anyway (which simply returns). As the real answer should be to either whitelist the section or have gcc ignore it fully. This change adds a option to recordmcount to warn when it finds a section that is ignored by ftrace but still contains mcount callers. This is not on by default as developers may not know if the section should be completely ignored or added to the whitelist. Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023738.476989377@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/recordmcount: Make ignored mcount calls into nops at compile timeSteven Rostedt
There are sections that are ignored by ftrace for the function tracing because the text is in a section that can be removed without notice. The mcount calls in these sections are ignored and ftrace never sees them. The downside of this is that the functions in these sections still call mcount. Although the mcount function is defined in assembly simply as a return, this added overhead is unnecessary. The solution is to convert these callers into nops at compile time. A better solution is to add 'notrace' to the section markers, but as new sections come up all the time, it would be nice that they are delt with when they are created. Later patches will deal with finding these sections and doing the proper solution. Thanks to H. Peter Anvin for giving me the right nops to use for x86. Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023738.237101176@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/recordmcount: Modify only executable sectionsSteven Rostedt
PROGBITS is not enough to determine if the section should be modified or not. Only process sections that are marked as executable. Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023737.991485123@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace: Add .kprobe.text section to whitelist for recordmcount.cSteven Rostedt
The .kprobe.text section is safe to modify mcount to nop and tracing. Add it to the whitelist in recordmcount.c and recordmcount.pl. Cc: John Reiser <jreiser@bitwagon.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/20110421023737.743350547@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/trivial: Clean up record mcount to use Linux switch styleSteven Rostedt
The Linux style for switch statements is: switch (var) { case x: [...] break; } Not: switch (var) { case x: { [...] } break; Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023737.523968644@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/trivial: Clean up recordmcount.c to use Linux style comparisonsSteven Rostedt
The Linux ftrace subsystem style for comparing is: var == 1 var > 0 and not: 1 == var 0 < var It is considered that Linux developers are smart enough not to do the if (var = 1) mistake. Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023737.290712238@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16Documentation, ABI: Update L3 cache index disable textBorislav Petkov
Change contact person to AMD kernel mailing list, update text and external references, drop "Users:" tag. Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/1305553188-21061-4-git-send-email-bp@amd64.org Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-16x86, AMD, cacheinfo: Fix L3 cache index disable checksFrank Arnold
We provide two slots to disable cache indices, and have a check to prevent both slots to be used for the same index. If the user disables the same index on different subcaches, both slots will hold the same index, e.g. $ echo 2047 > /sys/devices/system/cpu/cpu0/cache/index3/cache_disable_0 $ cat /sys/devices/system/cpu/cpu0/cache/index3/cache_disable_0 2047 $ echo 1050623 > /sys/devices/system/cpu/cpu0/cache/index3/cache_disable_1 $ cat /sys/devices/system/cpu/cpu0/cache/index3/cache_disable_1 2047 due to the fact that the check was looking only at index bits [11:0] and was ignoring writes to bits outside that range. The more correct fix is to simply check whether the index is within the bounds of [0..l3->indices]. While at it, cleanup comments and drop now-unused local macros. Signed-off-by: Frank Arnold <frank.arnold@amd.com> Link: http://lkml.kernel.org/r/1305553188-21061-3-git-send-email-bp@amd64.org Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-16x86, AMD, cacheinfo: Fix fallout caused by max3 conversionBorislav Petkov
732eacc0542d0aa48797f675888b85d6065af837 converted code around the kernel using nested max() macros to use the new max3 macro but forgot to remove the old line in intel_cacheinfo.c. Fix it. Cc: Hagen Paul Pfeifer <hagen@jauu.net> Cc: Frank Arnold <farnold@amd64.org> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/1305553188-21061-2-git-send-email-bp@amd64.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-05-16PM: Fix build issue in clock_ops.c for CONFIG_PM_RUNTIME unsetRafael J. Wysocki
Fix a build issue in drivers/base/power/clock_ops.c occuring when CONFIG_PM_RUNTIME is not set. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-16PM: Revert "driver core: platform_bus: allow runtime override of dev_pm_ops"Kevin Hilman
The platform_bus_set_pm_ops() operation is deprecated in favor of the new device power domain infrastructre implemented in commit 7538e3db6e015e890825fbd9f8659952896ddd5b (PM: add support for device power domains) Signed-off-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-16OMAP1 / PM: Use generic clock manipulation routines for runtime PMRafael J. Wysocki
Convert OMAP1 to using the new generic clock manipulation routines and a device power domain for runtime PM instead of overriding the platform bus type's runtime PM callbacks. This allows us to simplify OMAP1-specific code and to share some code with other platforms (shmobile in particular). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Kevin Hilman <khilman@ti.com>
2011-05-16xen/pci: Fix compiler error when CONFIG_XEN_PRIVILEGED_GUEST is not set.Konrad Rzeszutek Wilk
If we have CONFIG_XEN and the other parameters to build an Linux kernel that is non-privileged, the xen_[find|register|unregister]_ device_domain_owner functions should not be compiled. They should use the nops defined in arch/x86/include/asm/xen/pci.h instead. This fixes: arch/x86/pci/xen.c:496: error: redefinition of ‘xen_find_device_domain_owner’ arch/x86/include/asm/xen/pci.h:25: note: previous definition of ‘xen_find_device_domain_owner’ was here arch/x86/pci/xen.c:510: error: redefinition of ‘xen_register_device_domain_owner’ arch/x86/include/asm/xen/pci.h:29: note: previous definition of ‘xen_register_device_domain_owner’ was here arch/x86/pci/xen.c:532: error: redefinition of ‘xen_unregister_device_domain_owner’ arch/x86/include/asm/xen/pci.h:34: note: previous definition of ‘xen_unregister_device_domain_owner’ was here Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
2011-05-16Merge branch 'omap-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6 * 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6: OMAP3: set the core dpll clk rate in its set_rate function omap: iommu: Return IRQ_HANDLED in fault handler when no fault occured
2011-05-16Merge 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: Take lock around probes for drm_fb_helper_hotplug_event drm/i915: Revert i915.semaphore=1 default from 47ae63e0 vga_switcheroo: don't toggle-switch devices drm/radeon/kms: add some evergreen/ni safe regs drm/radeon/kms: fix extended lvds info parsing drm/radeon/kms: fix tiling reg on fusion
2011-05-16Revert "mmc: fix a race between card-detect rescan and clock-gate work ↵Chris Ball
instances" This reverts commit 26fc8775b51484d8c0a671198639c6d5ae60533e, which has been reported to cause boot/resume-time crashes for some users: https://bbs.archlinux.org/viewtopic.php?id=118751. Signed-off-by: Chris Ball <cjb@laptop.org> Cc: <stable@kernel.org>
2011-05-16blk-throttle: Use task_subsys_state() to determine a task's blkio_cgroupVivek Goyal
Currentlly we first map the task to cgroup and then cgroup to blkio_cgroup. There is a more direct way to get to blkio_cgroup from task using task_subsys_state(). Use that. The real reason for the fix is that it also avoids a race in generic cgroup code. During remount/umount rebind_subsystems() is called and it can do following with and rcu protection. cgrp->subsys[i] = NULL; That means if somebody got hold of cgroup under rcu and then it tried to do cgroup->subsys[] to get to blkio_cgroup, it would get NULL which is wrong. I was running into this race condition with ltp running on a upstream derived kernel and that lead to crash. So ideally we should also fix cgroup generic code to wait for rcu grace period before setting pointer to NULL. Li Zefan is not very keen on introducing synchronize_wait() as he thinks it will slow down moun/remount/umount operations. So for the time being atleast fix the kernel crash by taking a more direct route to blkio_cgroup. One tester had reported a crash while running LTP on a derived kernel and with this fix crash is no more seen while the test has been running for over 6 days. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-05-16x86, apic: Fix spurious error interrupts triggering on all non-boot APsYouquan Song
This patch fixes a bug reported by a customer, who found that many unreasonable error interrupts reported on all non-boot CPUs (APs) during the system boot stage. According to Chapter 10 of Intel Software Developer Manual Volume 3A, Local APIC may signal an illegal vector error when an LVT entry is set as an illegal vector value (0~15) under FIXED delivery mode (bits 8-11 is 0), regardless of whether the mask bit is set or an interrupt actually happen. These errors are seen as error interrupts. The initial value of thermal LVT entries on all APs always reads 0x10000 because APs are woken up by BSP issuing INIT-SIPI-SIPI sequence to them and LVT registers are reset to 0s except for the mask bits which are set to 1s when APs receive INIT IPI. When the BIOS takes over the thermal throttling interrupt, the LVT thermal deliver mode should be SMI and it is required from the kernel to keep AP's LVT thermal monitoring register programmed as such as well. This issue happens when BIOS does not take over thermal throttling interrupt, AP's LVT thermal monitor register will be restored to 0x10000 which means vector 0 and fixed deliver mode, so all APs will signal illegal vector error interrupts. This patch check if interrupt delivery mode is not fixed mode before restoring AP's LVT thermal monitor register. Signed-off-by: Youquan Song <youquan.song@intel.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Yong Wang <yong.y.wang@intel.com> Cc: hpa@linux.intel.com Cc: joe@perches.com Cc: jbaron@redhat.com Cc: trenn@suse.de Cc: kent.liu@intel.com Cc: chaohong.guo@intel.com Cc: <stable@kernel.org> # As far back as possible Link: http://lkml.kernel.org/r/1303402963-17738-1-git-send-email-youquan.song@intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-16sched: Fix and optimise calculation of the weight-inverseStephan Baerwolf
If the inverse loadweight should be zero, function "calc_delta_mine" calculates the inverse of "lw->weight" (in 32bit integer ops). This calculation is actually a little bit impure (because it is inverting something around "lw-weight"+1), especially when "lw->weight" becomes smaller. The correct inverse would be 1/lw->weight multiplied by "WMULT_CONST" for fixcomma-scaling it into integers. (So WMULT_CONST/lw->weight ...) The old, impure algorithm took two divisions for inverting lw->weight, the new, more exact one only takes one and an additional unlikely-if. Signed-off-by: Stephan Baerwolf <stephan.baerwolf@tu-ilmenau.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-0pz0wnyalr4tk4ln11xwumdx@git.kernel.org [ This could explain some aritmetical issues for small shares but nothing concrete has been reported yet so we are not confident enough to queue this up in sched/urgent and for -stable backport. But if anyone finds this commit and sees it to fix some badness then we can certainly change our mind! ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-16sched: Avoid going ahead if ->cpus_allowed is not changedYong Zhang
If cpumask_equal(&p->cpus_allowed, new_mask) is true, seems there is no reason to prevent set_cpus_allowed_ptr() return directly. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Acked-by: Hillf Danton <dhillf@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110509140705.GA2219@zhy Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-16sched, rt: Update rq clock when unthrottling of an otherwise idle CPUMike Galbraith
If an RT task is awakened while it's rt_rq is throttled, the time between wakeup/enqueue and unthrottle/selection may be accounted as rt_time if the CPU is idle. Set rq->skip_clock_update negative upon throttle release to tell put_prev_task() that we need a clock update. Reported-by: Thomas Giesel <skoe@directbox.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1304059010.7472.1.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-16sched: Fix rt_rq runtime leakage bugCheng Xu
This patch is to fix the real-time scheduler bug reported at: https://lkml.org/lkml/2011/4/26/13 That is, when running multiple real-time threads on every logical CPUs and then turning off one CPU, the kernel will bug at function __disable_runtime(). Function __disable_runtime() bugs and reports leakage of rt_rq runtime. The root cause is __disable_runtime() assumes it iterates through all the existing rt_rq's while walking rq->leaf_rt_rq_list, which actually contains only runnable rt_rq's. This problem also applies to __enable_runtime() and print_rt_stats(). The patch is based on above analysis, appears to fix the problem, but is only lightly tested. Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Cheng Xu <chengxu@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4DCE1F12.6040609@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-16drm: Take lock around probes for drm_fb_helper_hotplug_eventChris Wilson
We need to hold the dev->mode_config.mutex whilst detecting the output status. But we also need to drop it for the call into drm_fb_helper_single_fb_probe(), which indirectly acquires the lock when attaching the fbcon. Failure to do so exposes a race with normal output probing. Detected by adding some warnings that the mutex is held to the backend detect routines: [ 17.772456] WARNING: at drivers/gpu/drm/i915/intel_crt.c:471 intel_crt_detect+0x3e/0x373 [i915]() [ 17.772458] Hardware name: Latitude E6400 [ 17.772460] Modules linked in: .... [ 17.772582] Pid: 11, comm: kworker/0:1 Tainted: G W 2.6.38.4-custom.2 #8 [ 17.772584] Call Trace: [ 17.772591] [<ffffffff81046af5>] ? warn_slowpath_common+0x78/0x8c [ 17.772603] [<ffffffffa03f3e5c>] ? intel_crt_detect+0x3e/0x373 [i915] [ 17.772612] [<ffffffffa0355d49>] ? drm_helper_probe_single_connector_modes+0xbf/0x2af [drm_kms_helper] [ 17.772619] [<ffffffffa03534d5>] ? drm_fb_helper_probe_connector_modes+0x39/0x4d [drm_kms_helper] [ 17.772625] [<ffffffffa0354760>] ? drm_fb_helper_hotplug_event+0xa5/0xc3 [drm_kms_helper] [ 17.772633] [<ffffffffa035577f>] ? output_poll_execute+0x146/0x17c [drm_kms_helper] [ 17.772638] [<ffffffff81193c01>] ? cfq_init_queue+0x247/0x345 [ 17.772644] [<ffffffffa0355639>] ? output_poll_execute+0x0/0x17c [drm_kms_helper] [ 17.772648] [<ffffffff8105b540>] ? process_one_work+0x193/0x28e [ 17.772652] [<ffffffff8105c6bc>] ? worker_thread+0xef/0x172 [ 17.772655] [<ffffffff8105c5cd>] ? worker_thread+0x0/0x172 [ 17.772658] [<ffffffff8105c5cd>] ? worker_thread+0x0/0x172 [ 17.772663] [<ffffffff8105f767>] ? kthread+0x7a/0x82 [ 17.772668] [<ffffffff8100a724>] ? kernel_thread_helper+0x4/0x10 [ 17.772671] [<ffffffff8105f6ed>] ? kthread+0x0/0x82 [ 17.772674] [<ffffffff8100a720>] ? kernel_thread_helper+0x0/0x10 Reported-by: Frederik Himpe <fhimpe@telenet.be> References: https://bugs.freedesktop.org/show_bug.cgi?id=36394 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-05-16drm/i915: Revert i915.semaphore=1 default from 47ae63e0Andy Lutomirski
My Q67 / i7-2600 box has rev09 Sandy Bridge graphics. It hangs instantly when GNOME loads and it hangs so hard the reset button doesn't work. Setting i915.semaphore=0 fixes it. Semaphores were disabled in a1656b9090f7008d2941c314f5a64724bea2ae37 in 2.6.38 and were re-enabled by commit 47ae63e0c2e5fdb582d471dc906eb29be94c732f Merge: c59a333 467cffb Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Mon Mar 7 12:32:44 2011 +0000 Merge branch 'drm-intel-fixes' into drm-intel-next Apply the trivial conflicting regression fixes, but keep GPU semaphores enabled. Conflicts: drivers/gpu/drm/i915/i915_drv.h drivers/gpu/drm/i915/i915_gem_execbuffer.c (It's worth noting that the offending change is i915_drv.c, which is not a conflict.) Signed-off-by: Andy Lutomirski <luto@mit.edu> Acked-by: Keith Packard <keithp@keithp.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-05-16vga_switcheroo: don't toggle-switch devicesFlorian Mickler
If the requested device is already active, ignore the request. This restores the original behaviour of the interface. The change was probably an unintended side effect of commit 66b37c6777c4 vga_switcheroo: split switching into two stages which did not take into account to duplicate the !active check in the split-off stage2. Fix this by factoring that check out of stage1 into the debugfs_write routine. References: https://bugzilla.kernel.org/show_bug.cgi?id=34252 Reported-by: Igor Murzov <e-mail@date.by> Tested-by: Igor Murzov <e-mail@date.by> Signed-off-by: Florian Mickler <florian@mickler.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-05-15Merge branch 'pablo/nf-2.6-updates' of git://1984.lsi.us.es/net-2.6David S. Miller
2011-05-15Merge branch 'perf/urgent' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/urgent
2011-05-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: fix FS_IOC_SETFLAGS ioctl Btrfs: fix FS_IOC_GETFLAGS ioctl fs: remove FS_COW_FL Btrfs: fix easily get into ENOSPC in mixed case Prevent oopsing in posix_acl_valid()
2011-05-15IPVS: fix netns if reading ip_vs_* procfs entriesHans Schillstrom
Without this patch every access to ip_vs in procfs will increase the netns count i.e. an unbalanced get_net()/put_net(). (ipvsadm commands also use procfs.) The result is you can't exit a netns if reading ip_vs_* procfs entries. Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2011-05-15bridge: fix forwarding of IPv6Stephen Hemminger
The commit 6b1e960fdbd75dcd9bcc3ba5ff8898ff1ad30b6e bridge: Reset IPCB when entering IP stack on NF_FORWARD broke forwarding of IPV6 packets in bridge because it would call bp_parse_ip_options with an IPV6 packet. Reported-by: Noah Meyerhans <noahm@debian.org> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>