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* [S390] stp support.Martin Schwidefsky2008-07-141-150/+484
| | | | | | | Add support for clock synchronization with the server time protocol. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] initrd vs bss section clearing.Heiko Carstens2008-07-141-0/+18
| | | | | | | | | | | | | | In case the initrd is located within the bss section it will be overwritten when the section is cleared. To prevent this just move the initrd right behind the bss section if it starts within the section. The current code already moves the initrd if the bootmem allocator bitmap would overwrite it. With this patch we should be safe against initrd corruptions. Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Introduce user_regset accessors for s390Martin Schwidefsky2008-07-145-262/+327
| | | | | | | | | Add the user_regset definitions for normal and compat processes, replace the dump_regs core dump cruft with the generic CORE_DUMP_USER_REGSET and replace binfmt_elf32.c with the generic compat_binfmt_elf.c implementation. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [S390] Remove ipldelay kernel parameter.Heiko Carstens2008-07-141-26/+0
| | | | | | | | | Using the ipldelay kernel parameter leads to a crash at IPL time. Since this is broken since a long time it looks like nobody is using it anymore. So remove it instead of fixing it. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] make appldata compile w/o CONFIG_SWAPGerald Schaefer2008-07-141-0/+2
| | | | | | | | | Avoid compile error by using EXPORT_SYMBOL_GPL(si_swapinfo) only if CONFIG_SWAP is set. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* Merge branch 'kvm-updates-2.6.26' of ↵Linus Torvalds2008-06-114-22/+44
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm * 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: KVM: MMU: Fix is_empty_shadow_page() check KVM: MMU: Fix printk() format string KVM: IOAPIC: only set remote_irr if interrupt was injected KVM: MMU: reschedule during shadow teardown KVM: VMX: Clear CR4.VMXE in hardware_disable KVM: migrate PIT timer KVM: ppc: Report bad GFNs KVM: ppc: Use a read lock around MMU operations, and release it on error KVM: ppc: Remove unmatched kunmap() call KVM: ppc: add lwzx/stwz emulation KVM: ppc: Remove duplicate function KVM: s390: Fix race condition in kvm_s390_handle_wait KVM: s390: Send program check on access error KVM: s390: fix interrupt delivery KVM: s390: handle machine checks when guest is running KVM: s390: fix locking order problem in enable_sie KVM: s390: use yield instead of schedule to implement diag 0x44 KVM: x86 emulator: fix hypercall return value on AMD KVM: ia64: fix zero extending for mmio ld1/2/4 emulation in KVM
| * KVM: s390: Fix race condition in kvm_s390_handle_waitCarsten Otte2008-06-061-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | The call to add_timer was issued before local_int.lock was taken and before timer_due was set to 0. If the timer expires before the lock is being taken, the timer function will set timer_due to 1 and exit before the vcpu falls asleep. Depending on other external events, the vcpu might sleep forever. This fix pulls setting timer_due to the beginning of the function before add_timer, which ensures correct behavior. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
| * KVM: s390: Send program check on access errorCarsten Otte2008-06-061-1/+4
| | | | | | | | | | | | | | | | | | | | | | If the guest accesses non-existing memory, the sie64a function returns -EFAULT. We must check the return value and send a program check to the guest if the sie instruction faulted, otherwise the guest will loop at the faulting code. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
| * KVM: s390: fix interrupt deliveryCarsten Otte2008-06-061-1/+2
| | | | | | | | | | | | | | | | | | | | | | The current code delivers pending interrupts before it checks for need_resched. On a busy host, this can lead to a longer interrupt latency if the interrupt is injected while the process is scheduled away. This patch moves delivering the interrupt _after_ schedule(), which makes more sense. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
| * KVM: s390: handle machine checks when guest is runningChristian Borntraeger2008-06-061-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The low-level interrupt handler on s390 checks for _TIF_WORK_INT and exits the guest context, if work is pending. TIF_WORK_INT is defined as_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING. Currently the sie loop checks for signals and reschedule, but it does not check for machine checks. That means that we exit the guest context if a machine check is pending, but we do not handle the machine check. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> CC: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
| * KVM: s390: fix locking order problem in enable_sieChristian Borntraeger2008-06-061-17/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are potential locking problem in enable_sie. We take the task_lock and the mmap_sem. As exit_mm uses the same locks vice versa, this triggers a lockdep warning. The second problem is that dup_mm and mmput might sleep, so we must not hold the task_lock at that moment. The solution is to dup the mm unconditional and use the task_lock before and afterwards to check if we can use the new mm. dup_mm and mmput are called outside the task_lock, but we run update_mm while holding the task_lock, protection us against ptrace. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
| * KVM: s390: use yield instead of schedule to implement diag 0x44Christian Borntraeger2008-06-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | diag 0x44 is the common way on s390 to yield the cpu to the hypervisor. It is called by the guest in cpu_relax and in the spinlock code to yield to other guest cpus. This semantic is similar to yield. Lets replace the call to schedule with yield to make sure that current is really yielding. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* | [S390] Fix build failure in __cpu_up()Segher Boessenkool2008-06-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | The first argument to __ctl_store() should be the array to store stuff in, not just the first element of that array. With the current code in __cpu_up(), mainline GCC dies with an internal compiler error. I didn't diagnose that further, but just fixed the kernel bug. Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
* | [S390] vmemmap: fix off-by-one bug.Heiko Carstens2008-06-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | If a memory range is supposed to be added to the 1:1 mapping and it ends just below the maximum supported physical address it won't succeed. This is because a test doesn't consider that the end address is 1 smaller than start + size. Fix the comparison. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | [S390] sparsemem: use SPARSEMEM_STATIC if !64BIT.Heiko Carstens2008-06-101-0/+1
|/ | | | | | | | | | | | | | | | | | | In case of !64BIT kernel we end up with a zero sized mem_section array. This happens because NR_MEM_SECTIONS is smaller than SECTIONS_PER_ROOT but we have: #define NR_SECTION_ROOTS (NR_MEM_SECTIONS / SECTIONS_PER_ROOT) and struct mem_section *mem_section[NR_SECTION_ROOTS]; So fix this by selecting SPARSEMEM_STATIC which makes sure that SECTIONS_PER_ROOT is 1. Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Update default configuration.Martin Schwidefsky2008-05-301-3/+8
| | | | Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] disassembler: fix idte instruction format.Martin Schwidefsky2008-05-301-1/+1
| | | | | | | The correct instruction format of idte is "idte r1,r3,r2" with r1 at bit 24, r3 at bit 16 and r2 at bit 28. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] showmem: Only walk spanned pages.Heiko Carstens2008-05-301-26/+23
| | | | | | | | | | | Convert show_mem() so its nearly the same as on x86/powerpc. Gives us proper locking and we get also rid of the only use of max_mapnr. Also the number of pages was contained in an int which might not be sufficient not too far in the future. Cc: Johannes Weiner <hannes@saeurebad.de> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] appldata: prevent cpu hotplug when walking cpu_online_map.Gerald Schaefer2008-05-301-0/+8
| | | | | | | | Use get_online_cpus() to prevent cpu hotplug in situations where for_each_online_cpu() is called. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Fix section mismatch warnings.Heiko Carstens2008-05-302-6/+14
| | | | | | | | | | | | | | | | | | This fixes the last remaining section mismatch warnings in s390 architecture code. It reveals also a real bug introduced by... me with git commit 2069e978d5a6e7b45d58027e3de7f879b8c5e488 ("[S390] sparsemem vmemmap: initialize memmap.") Calling the generic vmemmap_alloc_block() function to get initialized memory is a nice idea, however that function is __meminit annotated and therefore the function might be gone if we try to call it later. This can happen if a DCSS segment gets added. So basically revert the patch and clear the memmap explicitly to fix the original bug. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] fix sparsemem related compile error with allnoconfig on s390Hans-Joachim Picht2008-05-301-0/+3
| | | | | | | | | | | | | | | On s390 make allnoconfig fails with the following build error: arch/s390/mm/init.c: In function 'show_mem': arch/s390/mm/init.c:55: error: implicit declaration of function 'pfn_valid' make[1]: *** [arch/s390/mm/init.o] Error 1 make: *** [arch/s390/mm] Error 2 This problem can by fixed ensuring that ARCH_SELECT_MEMORY_MODEL is always turned on. Signed-off-by: Hans-Joachim Picht <hans@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [PATCH] take init_files to fs/file.cAl Viro2008-05-161-1/+0
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [S390] show_interrupts: prevent cpu hotplug when walking cpu_online_map.Heiko Carstens2008-05-151-1/+2
| | | | | | | | Surround all the code withing show_interrupts() with get/put_online_cpus() to prevent strange results wrt cpu hotplug. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] smp: __smp_call_function_map vs cpu_online_map fix.Heiko Carstens2008-05-151-8/+8
| | | | | | | | | | | | Both smp_call_function() and __smp_call_function_map() access cpu_online_map. Both functions run with preemption disabled which protects for cpus going offline. However new cpus can be added and therefore the cpu_online_map can change unexpectedly. So use the call_lock to protect against changes to the cpu_online_map in start_secondary() and all smp_call_* functions. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] s390dbf: Use const char * for dbf name.Cornelia Huck2008-05-151-10/+10
| | | | | | | | We should use const char * for passing the name of the debug feature around since it will not be changed. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] sparsemem vmemmap: initialize memmap.Heiko Carstens2008-05-151-13/+6
| | | | | | | | | Let's just use the generic vmmemmap_alloc_block() function which always returns initialized memory. Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] guest page hinting lightMartin Schwidefsky2008-05-074-0/+90
| | | | | | | | Use the existing arch_alloc_page/arch_free_page callbacks to do the guest page state transitions between stable and unused. Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] compat ptrace cleanupRoland McGrath2008-05-072-95/+7
| | | | | | | | | | This removes redundant arch code for generic ptrace requests already handled by ptrace_request and compat_ptrace_request. It simplifies things to just have the standard entry points, and use the generic compat_sys_ptrace. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] s390-kvm: leave sie context on work. Removes preemption requirementChristian Borntraeger2008-05-074-6/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | From: Martin Schwidefsky <schwidefsky@de.ibm.com> This patch fixes a bug with cpu bound guest on kvm-s390. Sometimes it was impossible to deliver a signal to a spinning guest. We used preemption as a circumvention. The preemption notifiers called vcpu_load, which checked for pending signals and triggered a host intercept. But even with preemption, a sigkill was not delivered immediately. This patch changes the low level host interrupt handler to check for the SIE instruction, if TIF_WORK is set. In that case we change the instruction pointer of the return PSW to rerun the vcpu_run loop. The kvm code sees an intercept reason 0 if that happens. This patch adds accounting for these types of intercept as well. The advantages: - works with and without preemption - signals are delivered immediately - much better host latencies without preemption Acked-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] s390: Optimize user and work TIF checkMartin Schwidefsky2008-05-072-30/+28
| | | | | | | | | | | | On return from syscall or interrupt, we have to check if we return to userspace (likely) and if there is work todo (less likely) to decide if we handle the work. We can optimize this check: we first check for the less likely work case and then check for userspace. This patch is also a preparation for an additional patch, that fixes a bug in KVM dealing with cpu bound guests. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* unified (weak) sys_pipe implementationUlrich Drepper2008-05-031-17/+0
| | | | | | | | | | | | | | | | | | | This replaces the duplicated arch-specific versions of "sys_pipe()" with one unified implementation. This removes almost 250 lines of duplicated code. It's marked __weak, so that *if* an architecture wants to override the default implementation it can do so by simply having its own replacement version, since many architectures use alternate calling conventions for the 'pipe()' system call for legacy reasons (ie traditional UNIX implementations often return the two file descriptors in registers) I still haven't changed the cris version even though Linus says the BKL isn't needed. The arch maintainer can easily do it if there are really no obstacles. Signed-off-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6Linus Torvalds2008-04-3022-399/+513
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: [S390] Update default configuration. [S390] use generic sys_ptrace [S390] Remove self ptrace IEEE_IP hack. [S390] Convert to SPARSEMEM & SPARSEMEM_VMEMMAP [S390] System z large page support. [S390] Convert machine feature detection code to C. [S390] vmemmap: use clear_table to initialise page tables. [S390] Move stfl to system.h and delete duplicated version. [S390] uaccess_mvcos: #ifdef config dependent code. [S390] cpu topology: Fix possible deadlock. [S390] Add topology_core_siblings to topology.h [S390] cio: Make isc handling more robust. [S390] remove -traditional [S390] Automatically detect added cpus. [S390] smp: Fix locking order. [S390] Add missing ifndef/define to include/asm-s390/sysinfo.h. [S390] Move show_regs to traps.c. [S390] cio: Use strict_strtoul() for attributes.
| * [S390] Update default configuration.Martin Schwidefsky2008-04-301-41/+100
| | | | | | | | Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] use generic sys_ptraceMartin Schwidefsky2008-04-301-36/+1
| | | | | | | | | | | | | | After the PT_IEEE_IP hack has been removed s390 can now use the common code sys_ptrace function. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] Remove self ptrace IEEE_IP hack.Martin Schwidefsky2008-04-301-20/+0
| | | | | | | | | | | | | | | | | | | | | | The self referential PT_IEEE_IP ptrace peek & poke calls have been broken for that last 6 years. For peek the code always returns 0 instead of the last ieee fault and for poke the code does nothing. Since nobody noticed the code seems to be superfluous. So lets remove it. Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] Convert to SPARSEMEM & SPARSEMEM_VMEMMAPHeiko Carstens2008-04-304-79/+20
| | | | | | | | | | | | | | | | | | | | Convert s390 to SPARSEMEM and SPARSEMEM_VMEMMAP. We do a select of SPARSEMEM_VMEMMAP since it is configurable. This is because SPARSEMEM without SPARSEMEM_VMEMMAP gives us a hell of broken include dependencies that I don't want to fix. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] System z large page support.Gerald Schaefer2008-04-308-35/+210
| | | | | | | | | | | | | | | | | | | | | | This adds hugetlbfs support on System z, using both hardware large page support if available and software large page emulation on older hardware. Shared (large) page tables are implemented in software emulation mode, by using page->index of the first tail page from a compound large page to store page table information. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] Convert machine feature detection code to C.Heiko Carstens2008-04-304-127/+107
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | From: Heiko Carstens <heiko.carstens@de.ibm.com> From: Carsten Otte <cotte@de.ibm.com> This lets us use defines for the magic bits in machine flags instead of using plain numbers all over the place. In addition on newer machines features/facilities are indicated by the result of the stfl instruction. So we use these bits instead of trying to execute new instructions and check wether we get an exception or not. Also the mvpg instruction is always available when in zArch mode, whereas the idte instruction is only available in zArch mode. This results in some minor optimizations. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] vmemmap: use clear_table to initialise page tables.Heiko Carstens2008-04-301-3/+2
| | | | | | | | | | | | | | | | | | Always use clear_table to initialise page tables. The overlapping memcpy is just a leftover of a previous version that wasn't fully converted to clear_table. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] Move stfl to system.h and delete duplicated version.Heiko Carstens2008-04-302-19/+1
| | | | | | | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] uaccess_mvcos: #ifdef config dependent code.Heiko Carstens2008-04-301-0/+2
| | | | | | | | | | | | | | | | | | | | arch/s390/lib/uaccess_mvcos.c:166: warning: 'strnlen_user_mvcos' defined but not used arch/s390/lib/uaccess_mvcos.c:186: warning: 'strncpy_from_user_mvcos' defined but not used Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] cpu topology: Fix possible deadlock.Heiko Carstens2008-04-301-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we get a notification that cpu topology changed, we schedule a work struct which just calls arch_reinit_sched_domains. This function in turn calls get_online_cpus() which results int the lockdep warning below. After all it turnded out that it's not legal to call get_online_cpus() from the context of a multi-threaded work queue. It could deadlock this way: process 0 (events/cpu-x): -> run_workqueue -> removes my work_struct from the work queue -> calls work_struct->fn -> get_online_cpus() -> locks on cpu_hotplug.lock since process 1 below is doing cpu hotplug process 1: -> cpu_down (for cpu-x) -> cpu_hotplug_begin (holds cpu_hotplug.lock now) -> cpu-x dead -> notifier_call_chain with CPU_DEAD -> cleanup_workqueue_thread -> flush_cpu_workqueue (succeeds) -> kthread_stop for events/cpu-x -> now kthread_stop waits for my work_struct to complete from within process 0. -> dead. A single threaded workqueue wouldn't have such problems, however there is no such common queue available and it's not worth to create one for the very rare calls to arch_reinit_sched_domains. So we just create a kernel thread from our work struct which calls arch_reinit_sched_domains and are done with it. Thanks to Oleg Nesterov and Peter Zijlstra for helping me figuring out that this isn't a false positive lockdep warning: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.25-03562-g3dc5063-dirty #12 ------------------------------------------------------- events/3/14 is trying to acquire lock: (&cpu_hotplug.lock){--..}, at: [<0000000000076094>] get_online_cpus+0x50/0x78 but task is already holding lock: (topology_work){--..}, at: [<0000000000059cde>] run_workqueue+0x106/0x278 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (topology_work){--..}: [<000000000006fc74>] __lock_acquire+0x1010/0x111c [<000000000006fe40>] lock_acquire+0xc0/0xf8 [<0000000000059d48>] run_workqueue+0x170/0x278 [<0000000000059edc>] worker_thread+0x8c/0xf0 [<000000000005f5bc>] kthread+0x68/0xa0 [<000000000001a33e>] kernel_thread_starter+0x6/0xc [<000000000001a338>] kernel_thread_starter+0x0/0xc -> #1 (events){--..}: [<000000000006fc74>] __lock_acquire+0x1010/0x111c [<000000000006fe40>] lock_acquire+0xc0/0xf8 [<000000000005a23c>] cleanup_workqueue_thread+0x60/0xa8 [<00000000003b2ab8>] workqueue_cpu_callback+0xbc/0x170 [<00000000003bba80>] notifier_call_chain+0x5c/0xa4 [<00000000000655a2>] __raw_notifier_call_chain+0x26/0x38 [<00000000000655e2>] raw_notifier_call_chain+0x2e/0x40 [<0000000000075e00>] cpu_down+0x228/0x31c [<00000000003b1dd8>] store_online+0x64/0xb8 [<00000000001e7128>] sysdev_store+0x48/0x58 [<0000000000121cd2>] sysfs_write_file+0x126/0x1c0 [<00000000000c1944>] vfs_write+0xb0/0x15c [<00000000000c20e6>] sys_write+0x56/0x88 [<0000000000027a68>] sys32_write+0x34/0x4c [<0000000000023f70>] sysc_noemu+0x10/0x16 [<0000000077f3f186>] 0x77f3f186 -> #0 (&cpu_hotplug.lock){--..}: [<000000000006fa84>] __lock_acquire+0xe20/0x111c [<000000000006fe40>] lock_acquire+0xc0/0xf8 [<00000000003b701c>] mutex_lock_nested+0xd0/0x364 [<0000000000076094>] get_online_cpus+0x50/0x78 [<000000000003a03e>] arch_reinit_sched_domains+0x26/0x58 [<000000000002700e>] topology_work_fn+0x26/0x34 [<0000000000059d4e>] run_workqueue+0x176/0x278 [<0000000000059edc>] worker_thread+0x8c/0xf0 [<000000000005f5bc>] kthread+0x68/0xa0 [<000000000001a33e>] kernel_thread_starter+0x6/0xc [<000000000001a338>] kernel_thread_starter+0x0/0xc other info that might help us debug this: 2 locks held by events/3/14: #0: (events){--..}, at: [<0000000000059cde>] run_workqueue+0x106/0x278 #1: (topology_work){--..}, at: [<0000000000059cde>] run_workqueue+0x106/0x278 stack backtrace: CPU: 3 Not tainted 2.6.25-03562-g3dc5063-dirty #12 Process events/3 (pid: 14, task: 000000002fb04038, ksp: 000000002fb0bd70) 0400000000000000 000000002fb0ba40 0000000000000002 0000000000000000 000000002fb0bae0 000000002fb0ba58 000000002fb0ba58 0000000000016488 0000000000000000 000000002fb0bd70 0000000000000000 0000000000000000 000000002fb0ba40 000000000000000c 000000002fb0ba40 000000002fb0bab0 00000000003c99e0 0000000000016488 000000002fb0ba40 000000002fb0ba90 Call Trace: ([<00000000000163fc>] show_trace+0x138/0x158) [<00000000000164e2>] show_stack+0xc6/0xf8 [<0000000000016624>] dump_stack+0xb0/0xc0 [<000000000006cd36>] print_circular_bug_tail+0xa2/0xb4 [<000000000006fa84>] __lock_acquire+0xe20/0x111c [<000000000006fe40>] lock_acquire+0xc0/0xf8 [<00000000003b701c>] mutex_lock_nested+0xd0/0x364 [<0000000000076094>] get_online_cpus+0x50/0x78 [<000000000003a03e>] arch_reinit_sched_domains+0x26/0x58 [<000000000002700e>] topology_work_fn+0x26/0x34 [<0000000000059d4e>] run_workqueue+0x176/0x278 [<0000000000059edc>] worker_thread+0x8c/0xf0 [<000000000005f5bc>] kthread+0x68/0xa0 [<000000000001a33e>] kernel_thread_starter+0x6/0xc [<000000000001a338>] kernel_thread_starter+0x0/0xc INFO: lockdep is turned off. Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] Add topology_core_siblings to topology.hHeiko Carstens2008-04-301-3/+18
| | | | | | | | | | | | This exposes the core siblings to user space via sysfs. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
| * [S390] remove -traditionalMathieu Desnoyers2008-04-303-5/+0
| | | | | | | | | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] Automatically detect added cpus.Heiko Carstens2008-04-301-5/+14
| | | | | | | | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] smp: Fix locking order.Heiko Carstens2008-04-301-6/+6
| | | | | | | | | | | | | | | | | | | | | | On some smp sysfs store attributes get_online_cpus() may block on cpu_hotplug.lock, but we hold already smp_cpu_state_mutex. Since the locking order on cpu hotplug via arch_update_cpu_topology is inverse this might lead to deadlocks. So make sure locking order is always the same. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| * [S390] Move show_regs to traps.c.Heiko Carstens2008-04-302-22/+22
| | | | | | | | | | | | | | | | This is where it should be and we can get rid of some externs and a static inline function. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | signals: s390: renumber TIF_RESTORE_SIGMASKRoland McGrath2008-04-302-13/+13
|/ | | | | | | | | | | | | | | | TIF_RESTORE_SIGMASK no longer needs to be in the _TIF_WORK_* masks. Those low bits are scarce, and are all used up now. Renumber TIF_RESTORE_SIGMASK to free one up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390: use kbuild.h instead of defining macros in asm-offsets.cChristoph Lameter2008-04-291-28/+23
| | | | | | | | | | | | | | New version that does not preserve the marker. Arch maintainers indicate that the marker functionality is is not needed anymore. Note you may simplify the s390 asm-offsets.c code further if you use the OFFSET() macro instead of the DEFINE. See kbuild.h Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390: use kbuild.h instead of defining macros in asm-offsets.cChristoph Lameter2008-04-291-3/+2
| | | | | | | | | | | | | | s390 has a strange marker in DEFINE. Undefine the DEFINE from kbuild.h and define it the way s390 wants it to preserve things as they were. May be good if the arch maintainer could go over this and check if this workaround is really necessary. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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