The patch titled lockdep: irqtrace subsystem, docs has been added to the -mm tree. Its filename is lockdep-irqtrace-subsystem-docs.patch See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this ------------------------------------------------------ Subject: lockdep: irqtrace subsystem, docs From: Ingo Molnar <mingo@xxxxxxx> add Documentation/irqflags-tracing.txt. Signed-off-by: Ingo Molnar <mingo@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxx> --- Documentation/irqflags-tracing.txt | 57 +++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) diff -puN /dev/null Documentation/irqflags-tracing.txt --- /dev/null +++ a/Documentation/irqflags-tracing.txt @@ -0,0 +1,57 @@ +IRQ-flags state tracing + +started by Ingo Molnar <mingo@xxxxxxxxxx> + +the "irq-flags tracing" feature "traces" hardirq and softirq state, in +that it gives interested subsystems an opportunity to be notified of +every hardirqs-off/hardirqs-on, softirqs-off/softirqs-on event that +happens in the kernel. + +CONFIG_TRACE_IRQFLAGS_SUPPORT is needed for CONFIG_PROVE_SPIN_LOCKING +and CONFIG_PROVE_RW_LOCKING to be offered by the generic lock debugging +code. Otherwise only CONFIG_PROVE_MUTEX_LOCKING and +CONFIG_PROVE_RWSEM_LOCKING will be offered on an architecture - these +are locking APIs that are not used in IRQ context. (the one exception +for rwsems is worked around) + +architecture support for this is certainly not in the "trivial" +category, because lots of lowlevel assembly code deal with irq-flags +state changes. But an architecture can be irq-flags-tracing enabled in a +rather straightforward and risk-free manner. + +Architectures that want to support this need to do a couple of +code-organizational changes first: + +- move their irq-flags manipulation code from their asm/system.h header + to asm/irqflags.h + +- rename local_irq_disable()/etc to raw_local_irq_disable()/etc. so that + the linux/irqflags.h code can inject callbacks and can construct the + real local_irq_disable()/etc APIs. + +- add and enable TRACE_IRQFLAGS_SUPPORT in their arch level Kconfig file + +and then a couple of functional changes are needed as well to implement +irq-flags-tracing support: + +- in lowlevel entry code add (build-conditional) calls to the + trace_hardirqs_off()/trace_hardirqs_on() functions. The lock validator + closely guards whether the 'real' irq-flags matches the 'virtual' + irq-flags state, and complains loudly (and turns itself off) if the + two do not match. Usually most of the time for arch support for + irq-flags-tracing is spent in this state: look at the lockdep + complaint, try to figure out the assembly code we did not cover yet, + fix and repeat. Once the system has booted up and works without a + lockdep complaint in the irq-flags-tracing functions arch support is + complete. +- if the architecture has non-maskable interrupts then those need to be + excluded from the irq-tracing [and lock validation] mechanism via + lockdep_off()/lockdep_on(). + +in general there is no risk from having an incomplete irq-flags-tracing +implementation in an architecture: lockdep will detect that and will +turn itself off. I.e. the lock validator will still be reliable. There +should be no crashes due to irq-tracing bugs. (except if the assembly +changes break other code by modifying conditions or registers that +shouldnt be) + _ Patches currently in -mm which might be from mingo@xxxxxxx are origin.patch define-__raw_get_cpu_var-and-use-it.patch ide-cd-end-of-media-error-fix.patch lock-validator-introduce-warn_on_oncecond.patch emu10k1-mark-midi_spinlock-as-used.patch epoll-use-unlocked-wqueue-operations.patch pacct-none-delayed-process-accounting-accumulation.patch disable-debugging-version-of-write_lock.patch fix-drivers-mfd-ucb1x00-corec-irq-probing-bug.patch cifs-remove-f_ownerlock-use.patch lock-validator-fix-ns83820c-irq-flags-bug.patch revert-gregkh-pci-pci-test-that-drivers-properly-call-pci_set_master.patch x86-re-enable-generic-numa.patch i386-fix-softirq-accounting-with-4k-stacks.patch vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma.patch vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-tidy.patch vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-arch_vma_name-fix.patch vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-vs-x86_64-mm-reliable-stack-trace-support-i386.patch vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-vs-x86_64-mm-reliable-stack-trace-support-i386-2.patch vdso-randomize-the-i386-vdso-by-moving-it-into-a-vma-vs-x86_64-mm-reliable-stack-trace-support-i386-2-revert-maxmem-change.patch work-around-ppc64-bootup-bug-by-making-mutex-debugging-save-restore-irqs.patch kernel-kernel-cpuc-to-mutexes.patch spin-rwlock-init-cleanups.patch time-clocksource-infrastructure.patch sched-fix-smt-nice-lock-contention-and-optimization.patch sched-fix-smt-nice-lock-contention-and-optimization-tidy.patch sched-comment-bitmap-size-accounting.patch sched-fix-interactive-ceiling-code.patch sched-cpu-hotplug-race-vs-set_cpus_allowed.patch sched-implement-smpnice.patch sched-protect-calculation-of-max_pull-from-integer-wrap.patch sched-store-weighted-load-on-up.patch sched-add-discrete-weighted-cpu-load-function.patch sched-prevent-high-load-weight-tasks-suppressing-balancing.patch sched-improve-stability-of-smpnice-load-balancing.patch sched-improve-smpnice-load-balancing-when-load-per-task.patch smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing.patch smpnice-dont-consider-sched-groups-which-are-lightly-loaded-for-balancing-fix.patch sched-modify-move_tasks-to-improve-load-balancing-outcomes.patch sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks.patch sched-avoid-unnecessarily-moving-highest-priority-task-move_tasks-fix-2.patch sched_domain-handle-kmalloc-failure.patch sched_domain-handle-kmalloc-failure-fix.patch sched_domain-dont-use-gfp_atomic.patch sched_domain-use-kmalloc_node.patch sched_domain-allocate-sched_group-structures-dynamically.patch sched-mc-smt-power-savings-sched-policy.patch sched-uninline-task_rq_lock.patch bug-if-setscheduler-is-called-from-interrupt-context.patch sched-add-above-background-load-function.patch mm-implement-swap-prefetching.patch pi-futex-futex-code-cleanups.patch pi-futex-robust-futex-docs-fix.patch pi-futex-introduce-debug_check_no_locks_freed.patch pi-futex-introduce-warn_on_smp.patch pi-futex-add-plist-implementation.patch pi-futex-scheduler-support-for-pi.patch pi-futex-rt-mutex-core.patch pi-futex-rt-mutex-docs.patch pi-futex-rt-mutex-docs-update.patch pi-futex-rt-mutex-debug.patch pi-futex-rt-mutex-tester.patch pi-futex-rt-mutex-tester-fix.patch pi-futex-rt-mutex-futex-api.patch pi-futex-futex_lock_pi-futex_unlock_pi-support.patch pi-futex-futex_lock_pi-futex_unlock_pi-support-fix.patch fix-rt-mutex-defaults-and-dependencies.patch drop-tasklist-lock-in-do_sched_setscheduler.patch rtmutex-modify-rtmutex-tester-to-test-the-setscheduler.patch rtmutex-propagate-priority-settings-into-pi-lock-chains.patch rtmutex-propagate-priority-settings-into-pi-lock-chains-fix.patch futex_requeue-optimization.patch fix-ide-deadlock-in-error-reporting-code.patch genirq-rename-desc-handler-to-desc-chip.patch genirq-rename-desc-handler-to-desc-chip-power-fix.patch genirq-rename-desc-handler-to-desc-chip-ia64-fix.patch genirq-rename-desc-handler-to-desc-chip-ia64-fix-2.patch genirq-rename-desc-handler-to-desc-chip-terminate_irqs-fix.patch genirq-sem2mutex-probe_sem-probing_active.patch genirq-cleanup-merge-irq_affinity-into-irq_desc.patch genirq-cleanup-remove-irq_descp.patch genirq-cleanup-remove-irq_descp-fix.patch genirq-cleanup-remove-fastcall.patch genirq-cleanup-misc-code-cleanups.patch genirq-cleanup-reduce-irq_desc_t-use-mark-it-obsolete.patch genirq-cleanup-include-linux-irqh.patch genirq-cleanup-merge-irq_dir-smp_affinity_entry-into-irq_desc.patch genirq-cleanup-merge-pending_irq_cpumask-into-irq_desc.patch genirq-cleanup-turn-arch_has_irq_per_cpu-into-config_irq_per_cpu.patch genirq-debug-better-debug-printout-in-enable_irq.patch genirq-add-retrigger-irq-op-to-consolidate-hw_irq_resend.patch genirq-doc-comment-include-linux-irqh-structures.patch genirq-doc-handle_irq_event-and-__do_irq-comments.patch genirq-cleanup-no_irq_type-cleanups.patch genirq-doc-add-design-documentation.patch genirq-add-genirq-sw-irq-retrigger.patch genirq-add-irq_noprobe-support.patch genirq-add-irq_norequest-support.patch genirq-add-irq_noautoen-support.patch genirq-update-copyrights.patch genirq-core.patch genirq-msi-fixes-2.patch genirq-add-irq-chip-support.patch genirq-add-irq-chip-support-fix.patch genirq-add-irq-chip-support-misroute-irq-dont-call-desc-chip-end.patch genirq-add-handle_bad_irq.patch genirq-add-irq-wake-power-management-support.patch genirq-add-sa_trigger-support.patch genirq-cleanup-no_irq_type-no_irq_chip-rename.patch genirq-more-verbose-debugging-on-unexpected-irq-vectors.patch genirq-ia64-build-fix.patch genirq-add-irq_type_sense_mask.patch genirq-add-irq-chip-support-fasteoi-handler-handle-interrupt-disabling.patch genirq-irq-document-what-an-irq-is.patch genirq-add-chip-eoi-fastack-fasteoi-core.patch genirq-add-chip-eoi-fastack-fasteoi-fix.patch lockdep-floppyc-irq-release-fix.patch lockdep-acpi-locking-fix.patch lockdep-console_init-after-local_irq_enable.patch lockdep-add-is_module_address.patch lockdep-add-print_ip_sym.patch lockdep-add-per_cpu_offset.patch lockdep-add-disable-enable_irq_lockdep-api.patch lockdep-add-local_irq_enable_in_hardirq-api.patch lockdep-add-declare_completion_onstack-api.patch lockdep-clean-up-rwsems.patch lockdep-rename-debug_warn_on.patch lockdep-remove-debug_bug_on.patch lockdep-remove-mutex-deadlock-checking-code.patch lockdep-better-lock-debugging.patch lockdep-mutex-section-binutils-workaround.patch lockdep-locking-init-debugging-improvement.patch lockdep-beautify-x86_64-stacktraces.patch lockdep-x86_64-document-stack-frame-internals.patch lockdep-i386-remove-multi-entry-backtraces.patch lockdep-stacktrace-subsystem-core.patch lockdep-s390-config_frame_pointer-support.patch lockdep-stacktrace-subsystem-i386-support.patch lockdep-stacktrace-subsystem-x86_64-support.patch lockdep-stacktrace-subsystem-s390-support.patch lockdep-irqtrace-subsystem-core.patch lockdep-irqtrace-subsystem-docs.patch lockdep-irqtrace-subsystem-i386-support.patch lockdep-irqtrace-subsystem-x86_64-support.patch lockdep-irqtrace-subsystem-s390-support.patch lockdep-locking-api-self-tests.patch lockdep-irqtrace-cleanup-of-include-asm-i386-irqflagsh.patch lockdep-irqtrace-cleanup-of-include-asm-x86_64-irqflagsh.patch lockdep-core.patch lockdep-design-docs.patch lockdep-procfs.patch lockdep-prove-rwsem-locking-correctness.patch lockdep-prove-spinlock-rwlock-locking-correctness.patch lockdep-prove-mutex-locking-correctness.patch lockdep-kconfig.patch lockdep-print-all-lock-classes-on-sysrq-d.patch lockdep-x86_64-early-init.patch lockdep-x86-smp-alternatives-workaround.patch lockdep-do-not-recurse-in-printk.patch lockdep-fix-rt_hash_lock_sz.patch lockdep-s390-turn-validator-off-in-machine-check-handler.patch lockdep-enable-on-i386.patch lockdep-enable-on-x86_64.patch lockdep-enable-on-s390.patch lockdep-annotate-direct-io.patch lockdep-annotate-serial.patch lockdep-annotate-dcache.patch lockdep-annotate-i_mutex.patch lockdep-annotate-futex.patch lockdep-annotate-genirq.patch lockdep-annotate-waitqueues.patch lockdep-annotate-mm.patch lockdep-annotate-serio.patch lockdep-annotate-skb_queue_head_init.patch lockdep-annotate-timer-base-locks.patch lockdep-annotate-scheduler-runqueue-locks.patch lockdep-annotate-hrtimer-base-locks.patch lockdep-annotate-sock_lock_init.patch lockdep-annotate-af_unix-locking.patch lockdep-annotate-bh_lock_sock.patch lockdep-annotate-ieee1394-skb-queue-head-locking.patch lockdep-annotate-mmap_sem.patch lockdep-annotate-sunrpc-code.patch lockdep-annotate-ntfs-locking-rules.patch lockdep-annotate-the-quota-code.patch lockdep-annotate-usbfs.patch lockdep-annotate-sound-core-seq-seq_portsc.patch lockdep-annotate-sound-core-seq-seq_devicec.patch lockdep-annotate-8390c-disable_irq.patch lockdep-annotate-3c59xc-disable_irq.patch lockdep-annotate-forcedethc-disable_irq.patch lockdep-annotate-enable_in_hardirq.patch lockdep-annotate-on-stack-completions.patch lockdep-annotate-qeth-driver.patch lockdep-annotate-s_lock.patch lockdep-annotate-sb-s_umount.patch lockdep-annotate-slab-code.patch lockdep-annotate-blkdev-nesting.patch acpi-reduce-code-size-clean-up-fix-validator-message.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html