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* Merge branch 'core-fixes-for-linus-2' of ↵Linus Torvalds2008-08-12
|\ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask(), fix
| * generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask(), fixNick Piggin2008-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | > > Nick Piggin (1): > > generic-ipi: fix stack and rcu interaction bug in > > smp_call_function_mask() > > I'm still not 100% sure that I have this patch right... I might have seen > a lockup trace implicating the smp call function path... which may have > been due to some other problem or a different bug in the new call function > code, but if some more people can take a look at it before merging? OK indeed it did have a couple of bugs. Firstly, I wasn't freeing the data properly in the alloc && wait case. Secondly, I wasn't resetting CSD_FLAG_WAIT in the for each cpu loop (so only the first CPU would wait). After those fixes, the patch boots and runs with the kmalloc commented out (so it always executes the slowpath). Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds2008-08-12
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: fix spinlock recursion in hvc_console stop_machine: remove unused variable modules: extend initcall_debug functionality to the module loader export virtio_rng.h lguest: use get_user_pages_fast() instead of get_user_pages() mm: Make generic weak get_user_pages_fast and EXPORT_GPL it lguest: don't set MAC address for guest unless specified
| * | fix spinlock recursion in hvc_consoleChristian Borntraeger2008-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 611e097d7707741a336a0677d9d69bec40f29f3d Author: Christian Borntraeger <borntraeger@de.ibm.com> hvc_console: rework setup to replace irq functions with callbacks introduced a spinlock recursion problem. request_irq tries to call the handler if the IRQ is shared. The irq handler of hvc_console calls hvc_poll and hvc_kill which might take the hvc_struct spinlock. Therefore, we have to call request_irq outside the spinlock. We can move the notifier_add safely outside the spinlock as ->data must not be changed by the backend. Otherwise, tty_hangup would fail anyway. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | stop_machine: remove unused variableLi Zefan2008-08-12
| | | | | | | | | | | | | | | Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | modules: extend initcall_debug functionality to the module loaderArjan van de Ven2008-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel has this really nice facility where if you put "initcall_debug" on the kernel commandline, it'll print which function it's going to execute just before calling an initcall, and then after the call completes it will 1) print if it had an error code 2) checks for a few simple bugs (like leaving irqs off) and 3) print how long the init call took in milliseconds. While trying to optimize the boot speed of my laptop, I have been loving number 3 to figure out what to optimize... ... and then I wished that the same thing was done for module loading. This patch makes the module loader use this exact same functionality; it's a logical extension in my view (since modules are just sort of late binding initcalls anyway) and so far I've found it quite useful in finding where things are too slow in my boot. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | export virtio_rng.hChristian Borntraeger2008-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hello Rusty, The entropy device was added after we exported all virtio headers. This patch adds virtio_rng.h to the exportable userspace headers. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | lguest: use get_user_pages_fast() instead of get_user_pages()Rusty Russell2008-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using a simple page table thrashing program I measure a slight improvement. The program creates five processes. Each touches 1000 pages then schedules the next process. We repeat this 1000 times. As lguest only caches 4 cr3 values, this rebuilds a lot of shadow page tables requiring virt->phys mappings. Before: 5.93 seconds After: 5.40 seconds (Counts of slow vs fastpath in this usage are 6092 and 2852462 respectively.) And more importantly for lguest, the code is simpler. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | mm: Make generic weak get_user_pages_fast and EXPORT_GPL itRusty Russell2008-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Out of line get_user_pages_fast fallback implementation, make it a weak symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST. Export the symbol to modules so lguest can use it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | lguest: don't set MAC address for guest unless specifiedRusty Russell2008-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This shows up when trying to bridge: tap0: received packet with own address as source address As Max Krasnyansky points out, there's no reason to give the guest the same mac address as the TUN device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Max Krasnyansky <maxk@qualcomm.com>
* | | Merge branch 'agp-patches' of ↵Linus Torvalds2008-08-12
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6 * 'agp-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6: agp: fix SIS 5591/5592 wrong PCI id intel/agp: rewrite GTT on resume agp: use dev_printk when possible amd64-agp: run fallback when no bridges found, not when driver registration fails intel_agp: official name for GM45 chipset
| * | | agp: fix SIS 5591/5592 wrong PCI idKrzysztof Helt2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The correct id is the id of the main host (5591) not the id of the PCI-to-PCI bridge AGP (0001). Output from "lspci -nv" shows that only the former has AGP capabilities flag set: 00:00.0 0600: 1039:5591 (rev 02) Flags: bus master, medium devsel, latency 64 Memory at ec000000 (32-bit, non-prefetchable) [size=32M] Capabilities: [c0] AGP version 1.0 00:02.0 0604: 1039:0001 (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=01, subordinate=01, sec-latency=0 I/O behind bridge: 0000c000-0000cfff Memory behind bridge: eb500000-eb5fffff Prefetchable memory behind bridge: eb300000-eb3fffff Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> Signed-off-by: Dave Airlie <airlied@redhat.com>
| * | | intel/agp: rewrite GTT on resumeKeith Packard2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On my Intel chipset (965GM), the GTT is entirely erased across suspend/resume. This patch simply re-plays the current mapping at resume time to restore the table.=20 I noticed this once I started relying on persistent GTT mappings across VT switch in our GEM work -- the old X server and DRM code carefully unbind all memory from the GTT on VT switch, but GEM does not bother. I placed the list management and rewrite code in the generic layer on the assumption that it will be needed on other hardware, but I did not add the rewrite call to anything other than the Intel resume function. Keep a list of current GATT mappings. At resume time, rewrite them into the GATT. This is needed on Intel (at least) as the entire GATT is cleared across suspend/resume. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Keith Packard <keithp@keithp.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
| * | | agp: use dev_printk when possibleBjorn Helgaas2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert printks to use dev_printk(). Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
| * | | amd64-agp: run fallback when no bridges found, not when driver registration ↵Bjorn Helgaas2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fails I think the intent was that if no bridges matched agp_amd64_pci_table[], we would fall back to checking for any bridge with the AGP capability. But in the current code, we execute the fallback path only when pci_register_driver() itself fails, which is unrelated to whether any matching devices were found. This patch counts the AGP bridges found in the probe() method and executes the fallback path when none is found. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
| * | | intel_agp: official name for GM45 chipsetZhenyu Wang2008-08-11
| |/ / | | | | | | | | | | | | | | | | | | Signed-off-by: Zhenyu Wang <zhenyu.z.wang@intel.com> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
* | | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2008-08-11
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched, cpu hotplug: fix set_cpus_allowed() use in hotplug callbacks sched: fix mysql+oltp regression sched_clock: delay using sched_clock() sched clock: couple local and remote clocks sched clock: simplify __update_sched_clock() sched: eliminate scd->prev_raw sched clock: clean up sched_clock_cpu() sched clock: revert various sched_clock() changes sched: move sched_clock before first use sched: test runtime rather than period in global_rt_runtime() sched: fix SCHED_HRTICK dependency sched: fix warning in hrtick_start_fair()
| * \ \ Merge branch 'sched/clock' into sched/urgentIngo Molnar2008-08-11
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| | * \ \ Merge branch 'linus' into sched/clockIngo Molnar2008-08-11
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| | * | | | sched_clock: delay using sched_clock()Peter Zijlstra2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some arch's can't handle sched_clock() being called too early - delay this until sched_clock_init() has been called. Reported-by: Bill Gatliff <bgat@billgatliff.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Nishanth Aravamudan <nacc@us.ibm.com> CC: Russell King - ARM Linux <linux@arm.linux.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | sched clock: couple local and remote clocksIngo Molnar2008-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When taking the time of a remote CPU, use the opportunity to couple (sync) the clocks to each other. (in a monotonic way) Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | sched clock: simplify __update_sched_clock()Ingo Molnar2008-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - return the current clock instead of letting callers fetch it from scd->clock Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | sched: eliminate scd->prev_rawIngo Molnar2008-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | eliminate prev_raw and use tick_raw instead. It's enough to base the current time on the scheduler tick timestamp alone - the monotonicity and maximum checks will prevent any damage. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | sched clock: clean up sched_clock_cpu()Ingo Molnar2008-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - simplify the remote clock rebasing Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | sched clock: revert various sched_clock() changesIngo Molnar2008-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Found an interactivity problem on a quad core test-system - simple CPU loops would occasionally delay the system un an unacceptable way. After much debugging with Peter Zijlstra it turned out that the problem is caused by the string of sched_clock() changes - they caused the CPU clock to jump backwards a bit - which confuses the scheduler arithmetics. (which is unsigned for performance reasons) So revert: # c300ba2: sched_clock: and multiplier for TSC to gtod drift # c0c8773: sched_clock: only update deltas with local reads. # af52a90: sched_clock: stop maximum check on NO HZ # f7cce27: sched_clock: widen the max and min time This solves the interactivity problems. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | Merge branch 'sched/urgent' into sched/clockIngo Molnar2008-07-30
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| * | | | | | sched, cpu hotplug: fix set_cpus_allowed() use in hotplug callbacksDmitry Adamushko2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mark Langsdorf reported: > One of my co-workers noticed that the powernow-k8 > driver no longer restarts when a CPU core is > hot-disabled and then hot-enabled on AMD quad-core > systems. > > The following comands work fine on 2.6.26 and fail > on 2.6.27-rc1: > > echo 0 > /sys/devices/system/cpu/cpu3/online > echo 1 > /sys/devices/system/cpu/cpu3/online > find /sys -name cpufreq > > For 2.6.26, the find will return a cpufreq > directory for each processor. In 2.6.27-rc1, > the cpu3 directory is missing. > > After digging through the code, the following > logic is failing when the core is hot-enabled > at runtime. The code works during the boot > sequence. > > cpumask_t = current->cpus_allowed; > set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu)); > if (smp_processor_id() != cpu) > return -ENODEV; So set the CPU active before calling the CPU_ONLINE notifier chain, there are a handful of notifiers that use set_cpus_allowed(). This fix also solves the problem with x86-microcode. I've sent alternative patches for microcode, but as this "rely on set_cpus_allowed_ptr() being workable in cpu-hotplug(CPU_ONLINE, ...)" assumption seems to be more broad than what we thought, perhaps this fix should be applied. With this patch we define that by the moment CPU_ONLINE is being sent, a 'cpu' is online and ready for tasks to be migrated onto it. Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Reported-by: Mark Langsdorf <mark.langsdorf@amd.com> Tested-by: Mark Langsdorf <mark.langsdorf@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | sched: fix mysql+oltp regressionMike Galbraith2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Defer commit 6d299f1b53b84e2665f402d9bcc494800aba6386 to the next release. Testing of the tip/sched/clock tree revealed a mysql+oltp regression which bisection eventually traced back to this commit in mainline. Pertinent test results: Three run sysbench averages, throughput units in read/write requests/sec. clients 1 2 4 8 16 32 64 6e0534f 9646 17876 34774 33868 32230 30767 29441 2.6.26.1 9112 17936 34652 33383 31929 30665 29232 6d299f1 9112 14637 28370 33339 32038 30762 29204 Note: subsequent commits hide the majority of this regression until you apply the clock fixes, at which time it reemerges at full magnitude. We cannot see anything bad about the change itself so we defer it to the next release until this problem is fully analysed. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | Merge branch 'linus' into sched/urgentIngo Molnar2008-08-11
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| * | | | | | Merge branch 'linus' into sched/urgentIngo Molnar2008-07-31
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| * | | | | sched: move sched_clock before first useHugh Dickins2008-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move sched_clock() up to stop warning: weak declaration of `sched_clock' after first use results in unspecified behavior (if -fno-unit-at-a-time). Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Mike Travis <travis@sgi.com> Cc: Ben Herrenschmidt <benh@kernel.crashing.org> Cc: Linuxppc-dev@ozlabs.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: test runtime rather than period in global_rt_runtime()roel kluin2008-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test runtime rather than period Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: fix SCHED_HRTICK dependencyOGAWA Hirofumi2008-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, it seems SCHED_HRTICK allowed for !SMP. But, it seems to have no dependency of it. Fix it. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: fix warning in hrtick_start_fair()Peter Zijlstra2008-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Benjamin Herrenschmidt reported: > I get that on ppc64 ... > > In file included from kernel/sched.c:1595: > kernel/sched_fair.c: In function ‘hrtick_start_fair’: > kernel/sched_fair.c:902: warning: comparison of distinct pointer types lacks a cast > > Probably harmless but annoying. s64 delta = slice - ran; --> delta = max(10000LL, delta); Probably ppc64's s64 is long vs long long.. I think hpa was looking at sanitizing all these 64bit types across the architectures. Use max_t with an explicit type meanwhile. Reported-by: Benjamin Herrenschmid <benh@kernel.crashing.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2008-08-11
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: posix-timers: fix posix_timer_event() vs dequeue_signal() race posix-timers: do_schedule_next_timer: fix the setting of ->si_overrun
| * \ \ \ \ \ Merge branch 'timers/urgent' of ↵Ingo Molnar2008-07-27
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | ssh://master.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into timers/urgent
| | * | | | | | posix-timers: fix posix_timer_event() vs dequeue_signal() raceOleg Nesterov2008-07-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bug was reported and analysed by Mark McLoughlin <markmc@redhat.com>, the patch is based on his and Roland's suggestions. posix_timer_event() always rewrites the pre-allocated siginfo before sending the signal. Most of the written info is the same all the time, but memset(0) is very wrong. If ->sigq is queued we can race with collect_signal() which can fail to find this siginfo looking at .si_signo, or copy_siginfo() can copy the wrong .si_code/si_tid/etc. In short, sys_timer_settime() can in fact stop the active timer, or the user can receive the siginfo with the wrong .si_xxx values. Move "memset(->info, 0)" from posix_timer_event() to alloc_posix_timer(), change send_sigqueue() to set .si_overrun = 0 when ->sigq is not queued. It would be nice to move the whole sigq->info initialization from send to create path, but this is not easy to do without uglifying timer_create() further. As Roland rightly pointed out, we need more cleanups/fixes here, see the "FIXME" comment in the patch. Hopefully this patch makes sense anyway, and it can mask the most bad implications. Reported-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Mark McLoughlin <markmc@redhat.com> Cc: Oliver Pinter <oliver.pntr@gmail.com> Cc: Roland McGrath <roland@redhat.com> Cc: stable@kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> kernel/posix-timers.c | 17 +++++++++++++---- kernel/signal.c | 1 + 2 files changed, 14 insertions(+), 4 deletions(-)
| | * | | | | | posix-timers: do_schedule_next_timer: fix the setting of ->si_overrunOleg Nesterov2008-07-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | do_schedule_next_timer() sets info->si_overrun = timr->it_overrun_last, this discards the already accumulated overruns. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Mark McLoughlin <markmc@redhat.com> Cc: Oliver Pinter <oliver.pntr@gmail.com> Cc: Roland McGrath <roland@redhat.com> Cc: stable@kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | | | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2008-08-11
|\ \ \ \ \ \ \ \ | | |_|_|_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep: fix debug_lock_alloc lockdep: increase MAX_LOCKDEP_KEYS generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask() lockdep: fix overflow in the hlock shrinkage code lockdep: rename map_[acquire|release]() => lock_map_[acquire|release]() lockdep: handle chains involving classes defined in modules mm: fix mm_take_all_locks() locking order lockdep: annotate mm_take_all_locks() lockdep: spin_lock_nest_lock() lockdep: lock protection locks lockdep: map_acquire lockdep: shrink held_lock structure lockdep: re-annotate scheduler runqueues lockdep: lock_set_subclass - reset a held lock's subclass lockdep: change scheduler annotation debug_locks: set oops_in_progress if we will log messages. lockdep: fix combinatorial explosion in lock subgraph traversal
| * | | | | | | Merge branch 'core/locking' into core/urgentIngo Molnar2008-08-11
| |\ \ \ \ \ \ \
| | * | | | | | | lockdep: fix debug_lock_allocPeter Zijlstra2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we enable DEBUG_LOCK_ALLOC but do not enable PROVE_LOCKING and or LOCK_STAT, lock_alloc() and lock_release() turn into nops, even though we should be doing hlock checking (check=1). This causes a false warning and a lockdep self-disable. Rectify this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | lockdep: increase MAX_LOCKDEP_KEYSIngo Molnar2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | certain configs produce: [ 70.076229] BUG: MAX_LOCKDEP_KEYS too low! [ 70.080230] turning off the locking correctness validator. tune them up. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | lockdep: fix overflow in the hlock shrinkage codePeter Zijlstra2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a overflow by 1 case in the new shrunken hlock code. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | lockdep: rename map_[acquire|release]() => lock_map_[acquire|release]()Ingo Molnar2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the names were too generic: drivers/uio/uio.c:87: error: expected identifier or '(' before 'do' drivers/uio/uio.c:87: error: expected identifier or '(' before 'while' drivers/uio/uio.c:113: error: 'map_release' undeclared here (not in a function) Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | lockdep: handle chains involving classes defined in modulesRabin Vincent2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Solve this by marking the classes as unused and not printing information about the unused classes. Reported-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Rabin Vincent <rabin@rab.in> Acked-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | mm: fix mm_take_all_locks() locking orderPeter Zijlstra2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockdep spotted: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.27-rc1 #270 ------------------------------------------------------- qemu-kvm/2033 is trying to acquire lock: (&inode->i_data.i_mmap_lock){----}, at: [<ffffffff802996cc>] mm_take_all_locks+0xc2/0xea but task is already holding lock: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&anon_vma->lock){----}: [<ffffffff8025cd37>] __lock_acquire+0x11be/0x14d2 [<ffffffff8025d0a9>] lock_acquire+0x5e/0x7a [<ffffffff804c655b>] _spin_lock+0x3b/0x47 [<ffffffff8029a2ef>] vma_adjust+0x200/0x444 [<ffffffff8029a662>] split_vma+0x12f/0x146 [<ffffffff8029bc60>] mprotect_fixup+0x13c/0x536 [<ffffffff8029c203>] sys_mprotect+0x1a9/0x21e [<ffffffff8020c0db>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff -> #0 (&inode->i_data.i_mmap_lock){----}: [<ffffffff8025ca54>] __lock_acquire+0xedb/0x14d2 [<ffffffff8025d397>] lock_release_non_nested+0x1c2/0x219 [<ffffffff8025d515>] lock_release+0x127/0x14a [<ffffffff804c6403>] _spin_unlock+0x1e/0x50 [<ffffffff802995d9>] mm_drop_all_locks+0x7f/0xb0 [<ffffffff802a965d>] do_mmu_notifier_register+0xe2/0x112 [<ffffffff802a96a8>] mmu_notifier_register+0xe/0x10 [<ffffffffa0043b6b>] kvm_dev_ioctl+0x11e/0x287 [kvm] [<ffffffff802bd0ca>] vfs_ioctl+0x2a/0x78 [<ffffffff802bd36f>] do_vfs_ioctl+0x257/0x274 [<ffffffff802bd3e1>] sys_ioctl+0x55/0x78 [<ffffffff8020c0db>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff other info that might help us debug this: 5 locks held by qemu-kvm/2033: #0: (&mm->mmap_sem){----}, at: [<ffffffff802a95d0>] do_mmu_notifier_register+0x55/0x112 #1: (mm_all_locks_mutex){--..}, at: [<ffffffff8029963e>] mm_take_all_locks+0x34/0xea #2: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea #3: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea #4: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea stack backtrace: Pid: 2033, comm: qemu-kvm Not tainted 2.6.27-rc1 #270 Call Trace: [<ffffffff8025b7c7>] print_circular_bug_tail+0xb8/0xc3 [<ffffffff8025ca54>] __lock_acquire+0xedb/0x14d2 [<ffffffff80259bb1>] ? add_lock_to_list+0x7e/0xad [<ffffffff8029967a>] ? mm_take_all_locks+0x70/0xea [<ffffffff8029967a>] ? mm_take_all_locks+0x70/0xea [<ffffffff8025d397>] lock_release_non_nested+0x1c2/0x219 [<ffffffff802996cc>] ? mm_take_all_locks+0xc2/0xea [<ffffffff802996cc>] ? mm_take_all_locks+0xc2/0xea [<ffffffff8025b202>] ? trace_hardirqs_on_caller+0x4d/0x115 [<ffffffff802995d9>] ? mm_drop_all_locks+0x7f/0xb0 [<ffffffff8025d515>] lock_release+0x127/0x14a [<ffffffff804c6403>] _spin_unlock+0x1e/0x50 [<ffffffff802995d9>] mm_drop_all_locks+0x7f/0xb0 [<ffffffff802a965d>] do_mmu_notifier_register+0xe2/0x112 [<ffffffff802a96a8>] mmu_notifier_register+0xe/0x10 [<ffffffffa0043b6b>] kvm_dev_ioctl+0x11e/0x287 [kvm] [<ffffffff8033f9f2>] ? file_has_perm+0x83/0x8e [<ffffffff802bd0ca>] vfs_ioctl+0x2a/0x78 [<ffffffff802bd36f>] do_vfs_ioctl+0x257/0x274 [<ffffffff802bd3e1>] sys_ioctl+0x55/0x78 [<ffffffff8020c0db>] system_call_fastpath+0x16/0x1b Which the locking hierarchy in mm/rmap.c confirms as valid. Fix this by first taking all the mapping->i_mmap_lock instances and then take all anon_vma->lock instances. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | lockdep: annotate mm_take_all_locks()Peter Zijlstra2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The nesting is correct due to holding mmap_sem, use the new annotation to annotate this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | lockdep: spin_lock_nest_lock()Peter Zijlstra2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Expose the new lock protection lock. This can be used to annotate places where we take multiple locks of the same class and avoid deadlocks by always taking another (top-level) lock first. NOTE: we're still bound to the MAX_LOCK_DEPTH (48) limit. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | lockdep: lock protection locksPeter Zijlstra2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Fri, 2008-08-01 at 16:26 -0700, Linus Torvalds wrote: > On Fri, 1 Aug 2008, David Miller wrote: > > > > Taking more than a few locks of the same class at once is bad > > news and it's better to find an alternative method. > > It's not always wrong. > > If you can guarantee that anybody that takes more than one lock of a > particular class will always take a single top-level lock _first_, then > that's all good. You can obviously screw up and take the same lock _twice_ > (which will deadlock), but at least you cannot get into ABBA situations. > > So maybe the right thing to do is to just teach lockdep about "lock > protection locks". That would have solved the multi-queue issues for > networking too - all the actual network drivers would still have taken > just their single queue lock, but the one case that needs to take all of > them would have taken a separate top-level lock first. > > Never mind that the multi-queue locks were always taken in the same order: > it's never wrong to just have some top-level serialization, and anybody > who needs to take <n> locks might as well do <n+1>, because they sure as > hell aren't going to be on _any_ fastpaths. > > So the simplest solution really sounds like just teaching lockdep about > that one special case. It's not "nesting" exactly, although it's obviously > related to it. Do as Linus suggested. The lock protection lock is called nest_lock. Note that we still have the MAX_LOCK_DEPTH (48) limit to consider, so anything that spills that it still up shit creek. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | lockdep: map_acquirePeter Zijlstra2008-08-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most the free-standing lock_acquire() usages look remarkably similar, sweep them into a new helper. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>