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2016-11-15tracing: Add new trace_marker_rawSteven Rostedt4-31/+181
A new file is created: /sys/kernel/debug/tracing/trace_marker_raw This allows for appications to create data structures and write the binary data directly into it, and then read the trace data out from trace_pipe_raw into the same type of data structure. This saves on converting numbers into ASCII that would be required by trace_marker. Suggested-by: Olof Johansson <olof@lixom.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-15tracing: Allow wakeup_dl tracer to be used by instancesZhou Chengming1-0/+1
Allow wakeup_dl tracer to be used by instances, like wakeup tracer and wakeup_rt tracer. Link: http://lkml.kernel.org/r/1479093553-31264-1-git-send-email-zhouchengming1@huawei.com Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-15tracing/filter: Define op as the enum that it isSteven Rostedt (Red Hat)1-10/+12
The trace_events_file.c filter logic can be a bit complex. I copy this into a userspace program where I can debug it a bit easier. One issue is the op is defined in most places as an int instead of as an enum, and gdb just gives the value when debugging. Having the actual op name shown in gdb is more useful. This has no functionality change, but helps in debugging when the file is debugged in user space. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-15tracing: Optimise comparison filters and fix binary and for 64 bitSteven Rostedt (Red Hat)1-32/+48
Currently the filter logic for comparisons (like greater-than and less-than) are used, they share the same function and a switch statement is used to jump to the comparison type to perform. This is done in the extreme hot path of the tracing code, and it does not take much more space to create a unique comparison function to perform each type of comparison and remove the switch statement. Also, a bug was found where the binary and operation for 64 bits could fail if the resulting bits were greater than 32 bits, because the result was passed into a 32 bit variable. This was fixed when adding the separate binary and function. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-15ftrace: Support full glob matchingMasami Hiramatsu5-2/+25
Use glob_match() to support flexible glob wildcards (*,?) and character classes ([) for ftrace. Since the full glob matching is slower than the current partial matching routines(*pat, pat*, *pat*), this leaves those routines and just add MATCH_GLOB for complex glob expression. e.g. ---- [root@localhost tracing]# echo 'sched*group' > set_ftrace_filter [root@localhost tracing]# cat set_ftrace_filter sched_free_group sched_change_group sched_create_group sched_online_group sched_destroy_group sched_offline_group [root@localhost tracing]# echo '[Ss]y[Ss]_*' > set_ftrace_filter [root@localhost tracing]# head set_ftrace_filter sys_arch_prctl sys_rt_sigreturn sys_ioperm SyS_iopl sys_modify_ldt SyS_mmap SyS_set_thread_area SyS_get_thread_area SyS_set_tid_address sys_fork ---- Link: http://lkml.kernel.org/r/147566869501.29136.6462645009894738056.stgit@devbox Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-15ftrace: Add more checks for FTRACE_FL_DISABLED in processing ip recordsSteven Rostedt (Red Hat)1-0/+22
When a module is first loaded and its function ip records are added to the ftrace list of functions to modify, they are set to DISABLED, as their text is still in a read only state. When the module is fully loaded, and can be updated, the flag is cleared, and if their's any functions that should be tracing them, it is updated at that moment. But there's several locations that do record accounting and should ignore records that are marked as disabled, or they can cause issues. Alexei already fixed one location, but others need to be addressed. Cc: stable@vger.kernel.org Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-15ftrace: Ignore FTRACE_FL_DISABLED while walking dyn_ftrace recordsAlexei Starovoitov1-1/+1
ftrace_shutdown() checks for sanity of ftrace records and if dyn_ftrace->flags is not zero, it will warn. It can happen that 'flags' are set to FTRACE_FL_DISABLED at this point, since some module was loaded, but before ftrace_module_enable() cleared the flags for this module. In other words the module.c is doing: ftrace_module_init(mod); // calls ftrace_update_code() that sets flags=FTRACE_FL_DISABLED ... // here ftrace_shutdown() is called that warns, since err = prepare_coming_module(mod); // didn't have a chance to clear FTRACE_FL_DISABLED Fix it by ignoring disabled records. It's similar to what __ftrace_hash_rec_update() is already doing. Link: http://lkml.kernel.org/r/1478560460-3818619-1-git-send-email-ast@fb.com Cc: stable@vger.kernel.org Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-12Merge tag 'pm-4.9-rc5' of ↵Linus Torvalds1-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These fix two bugs in error code paths in the PM core (system-wide suspend of devices), a device reference leak in the boot-time suspend test code and a cpupower utility regression from the 4.7 cycle. Specifics: - Prevent the PM core from attempting to suspend parent devices if any of their children, whose suspend callbacks were invoked asynchronously, have failed to suspend during the "late" and "noirq" phases of system-wide suspend of devices (Brian Norris). - Prevent the boot-time system suspend test code from leaking a reference to the RTC device used by it (Johan Hovold). - Fix cpupower to use the return value of one of its library functions correctly and restore the correct behavior of it when used for setting cpufreq tunables broken during the 4.7 development cycle (Laura Abbott)" * tag 'pm-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM / sleep: don't suspend parent when async child suspend_{noirq, late} fails PM / sleep: fix device reference leak in test_suspend cpupower: Correct return type of cpu_power_is_cpu_online() in cpufreq-set
2016-11-12Merge branches 'pm-tools-fixes' and 'pm-sleep-fixes'Rafael J. Wysocki1-1/+3
* pm-tools-fixes: cpupower: Correct return type of cpu_power_is_cpu_online() in cpufreq-set * pm-sleep-fixes: PM / sleep: don't suspend parent when async child suspend_{noirq, late} fails PM / sleep: fix device reference leak in test_suspend
2016-11-11Revert "console: don't prefer first registered if DT specifies stdout-path"Hans de Goede1-12/+1
This reverts commit 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path"). The reverted commit changes existing behavior on which many ARM boards rely. Many ARM small-board-computers, like e.g. the Raspberry Pi have both a video output and a serial console. Depending on whether the user is using the device as a more regular computer; or as a headless device we need to have the console on either one or the other. Many users rely on the kernel behavior of the console being present on both outputs, before the reverted commit the console setup with no console= kernel arguments on an ARM board which sets stdout-path in dt would look like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 tty0 -WU (E p ) 4:1 Where as after the reverted commit, it looks like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 This commit reverts commit 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path") restoring the original behavior. Fixes: 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path") Link: http://lkml.kernel.org/r/20161104121135.4780-2-hdegoede@redhat.com Signed-off-by: Hans de Goede <hdegoede@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-05Merge branches 'sched-urgent-for-linus' and 'core-urgent-for-linus' of ↵Linus Torvalds2-9/+7
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull stack vmap fixups from Thomas Gleixner: "Two small patches related to sched_show_task(): - make sure to hold a reference on the task stack while accessing it - remove the thread_saved_pc printout .. and add a sanity check into release_task_stack() to catch problems with task stack references" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Remove pointless printout in sched_show_task() sched/core: Fix oops in sched_show_task() * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: fork: Add task stack refcounting sanity check and prevent premature task stack freeing
2016-11-03sched/core: Remove pointless printout in sched_show_task()Linus Torvalds1-9/+0
In sched_show_task() we print out a useless hex number, not even a symbol, and there's a big question mark whether this even makes sense anyway, I suspect we should just remove it all. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: brgerst@gmail.com Cc: jann@thejh.net Cc: keescook@chromium.org Cc: linux-api@vger.kernel.org Cc: tycho.andersen@canonical.com Link: http://lkml.kernel.org/r/CA+55aFzphURPFzAvU4z6Moy7ZmimcwPuUdYU8bj9z0J+S8X1rw@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-03sched/core: Fix oops in sched_show_task()Tetsuo Handa1-0/+3
When CONFIG_THREAD_INFO_IN_TASK=y, it is possible that an exited thread remains in the task list after its stack pointer was already set to NULL. Therefore, thread_saved_pc() and stack_not_used() in sched_show_task() will trigger NULL pointer dereference if an attempt to dump such thread's traces (e.g. SysRq-t, khungtaskd) is made. Since show_stack() in sched_show_task() calls try_get_task_stack() and sched_show_task() is called from interrupt context, calling try_get_task_stack() from sched_show_task() will be safe as well. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: brgerst@gmail.com Cc: jann@thejh.net Cc: keescook@chromium.org Cc: linux-api@vger.kernel.org Cc: tycho.andersen@canonical.com Link: http://lkml.kernel.org/r/201611021950.FEJ34368.HFFJOOMLtQOVSF@I-love.SAKURA.ne.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-02PM / sleep: fix device reference leak in test_suspendJohan Hovold1-1/+3
Make sure to drop the reference taken by class_find_device() after opening the RTC device. Fixes: 77437fd4e61f (pm: boot time suspend selftest) Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-01fork: Add task stack refcounting sanity check and prevent premature task ↵Andy Lutomirski1-0/+4
stack freeing If something goes wrong with task stack refcounting and a stack refcount hits zero too early, warn and leak it rather than potentially freeing it early (and silently). Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f29119c783a9680a4b4656e751b6123917ace94b.1477926663.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-29Merge tag 'pm-4.9-rc3' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These fix two intel_pstate issues related to the way it works when the scaling_governor sysfs attribute is set to "performance" and fix up messages in the system suspend core code. Specifics: - Fix a missing KERN_CONT in a system suspend message by converting the affected code to using pr_info() and pr_cont() instead of the "raw" printk() (Jon Hunter). - Make intel_pstate set the CPU P-state from its .set_policy() callback when the scaling_governor sysfs attribute is set to "performance" so that it interacts with NOHZ_FULL more predictably which was the case before 4.7 (Rafael Wysocki). - Make intel_pstate always request the maximum allowed P-state when the scaling_governor sysfs attribute is set to "performance" to prevent it from effectively ingoring that setting is some situations (Rafael Wysocki)" * tag 'pm-4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpufreq: intel_pstate: Always set max P-state in performance mode PM / suspend: Fix missing KERN_CONT for suspend message cpufreq: intel_pstate: Set P-state upfront in performance mode
2016-10-29Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-6/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc kernel fixes: a virtualization environment related fix, an uncore PMU driver removal handling fix, a PowerPC fix and new events for Knights Landing" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Honour the CPUID for number of fixed counters in hypervisors perf/powerpc: Don't call perf_event_disable() from atomic context perf/core: Protect PMU device removal with a 'pmu_bus_running' check, to fix CONFIG_DEBUG_TEST_DRIVER_REMOVE=y kernel panic perf/x86/intel/cstate: Add C-state residency events for Knights Landing
2016-10-28Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds1-30/+44
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: "Fix four timer locking races: two were noticed by Linus while reviewing the code while chasing for a corruption bug, and two from fixing spurious USB timeouts" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers: Prevent base clock corruption when forwarding timers: Prevent base clock rewind when forwarding clock timers: Lock base for same bucket optimization timers: Plug locking race vs. timer migration
2016-10-28Merge branches 'core-urgent-for-linus', 'irq-urgent-for-linus' and ↵Linus Torvalds1-3/+0
'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool, irq and scheduler fixes from Ingo Molnar: "One more objtool fixlet for GCC6 code generation patterns, an irq DocBook fix and an unused variable warning fix in the scheduler" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix rare switch jump table pattern detection * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: doc: Add missing parameter for msi_setup * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Remove unused but set variable 'rq'
2016-10-28perf/powerpc: Don't call perf_event_disable() from atomic contextJiri Olsa1-2/+8
The trinity syscall fuzzer triggered following WARN() on powerpc: WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278 ... NIP [c00000000093aedc] .hw_breakpoint_handler+0x28c/0x2b0 LR [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 Call Trace: [c0000002f7933580] [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 (unreliable) [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0 [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0 [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0 [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100 [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48 Followed by a lockdep warning: =============================== [ INFO: suspicious RCU usage. ] 4.8.0-rc5+ #7 Tainted: G W ------------------------------- ./include/linux/rcupdate.h:556 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by ls/2998: #0: (rcu_read_lock){......}, at: [<c0000000000f6a00>] .__atomic_notifier_call_chain+0x0/0x1c0 #1: (rcu_read_lock){......}, at: [<c00000000093ac50>] .hw_breakpoint_handler+0x0/0x2b0 stack backtrace: CPU: 9 PID: 2998 Comm: ls Tainted: G W 4.8.0-rc5+ #7 Call Trace: [c0000002f7933150] [c00000000094b1f8] .dump_stack+0xe0/0x14c (unreliable) [c0000002f79331e0] [c00000000013c468] .lockdep_rcu_suspicious+0x138/0x180 [c0000002f7933270] [c0000000001005d8] .___might_sleep+0x278/0x2e0 [c0000002f7933300] [c000000000935584] .mutex_lock_nested+0x64/0x5a0 [c0000002f7933410] [c00000000023084c] .perf_event_ctx_lock_nested+0x16c/0x380 [c0000002f7933500] [c000000000230a80] .perf_event_disable+0x20/0x60 [c0000002f7933580] [c00000000093aeec] .hw_breakpoint_handler+0x29c/0x2b0 [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0 [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0 [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0 [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100 [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48 While it looks like the first WARN() is probably valid, the other one is triggered by disabling event via perf_event_disable() from atomic context. The event is disabled here in case we were not able to emulate the instruction that hit the breakpoint. By disabling the event we unschedule the event and make sure it's not scheduled back. But we can't call perf_event_disable() from atomic context, instead we need to use the event's pending_disable irq_work method to disable it. Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161026094824.GA21397@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-28perf/core: Protect PMU device removal with a 'pmu_bus_running' check, to fix ↵Jiri Olsa1-4/+9
CONFIG_DEBUG_TEST_DRIVER_REMOVE=y kernel panic CAI Qian reported a crash in the PMU uncore device removal code, enabled by the CONFIG_DEBUG_TEST_DRIVER_REMOVE=y option: https://marc.info/?l=linux-kernel&m=147688837328451 The reason for the crash is that perf_pmu_unregister() tries to remove a PMU device which is not added at this point. We add PMU devices only after pmu_bus is registered, which happens in the perf_event_sysfs_init() call and sets the 'pmu_bus_running' flag. The fix is to get the 'pmu_bus_running' flag state at the point the PMU is taken out of the PMU list and remove the device later only if it's set. Reported-by: CAI Qian <caiqian@redhat.com> Tested-by: CAI Qian <caiqian@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Herring <robh@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161020111011.GA13361@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-28kcov: properly check if we are in an interruptAndrey Konovalov1-1/+8
in_interrupt() returns a nonzero value when we are either in an interrupt or have bh disabled via local_bh_disable(). Since we are interested in only ignoring coverage from actual interrupts, do a proper check instead of just calling in_interrupt(). As a result of this change, kcov will start to collect coverage from within local_bh_disable()/local_bh_enable() sections. Link: http://lkml.kernel.org/r/1476115803-20712-1-git-send-email-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Nicolai Stange <nicstange@gmail.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kees Cook <keescook@chromium.org> Cc: James Morse <james.morse@arm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-27Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+1
Pull block fixes from Jens Axboe: "A set of fixes for this series, most notably the fix for the blk-mq software queue regression in from this merge window. Apart from that, a fix for an unlikely hang if a queue is flooded with FUA requests from Ming, and a few small fixes for nbd and badblocks. Lastly, a rename update for the proc softirq output, since the block polling code was made generic" * 'for-linus' of git://git.kernel.dk/linux-block: blk-mq: update hardware and software queues for sleeping alloc block: flush: fix IO hang in case of flood fua req nbd: fix incorrect unlock of nbd->sock_lock in sock_shutdown badblocks: badblocks_set/clear update unacked_exist softirq: Display IRQ_POLL for irq-poll statistics
2016-10-27mm: remove per-zone hashtable of bitlock waitqueuesLinus Torvalds2-10/+16
The per-zone waitqueues exist because of a scalability issue with the page waitqueues on some NUMA machines, but it turns out that they hurt normal loads, and now with the vmalloced stacks they also end up breaking gfs2 that uses a bit_wait on a stack object: wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE) where 'gh' can be a reference to the local variable 'mount_gh' on the stack of fill_super(). The reason the per-zone hash table breaks for this case is that there is no "zone" for virtual allocations, and trying to look up the physical page to get at it will fail (with a BUG_ON()). It turns out that I actually complained to the mm people about the per-zone hash table for another reason just a month ago: the zone lookup also hurts the regular use of "unlock_page()" a lot, because the zone lookup ends up forcing several unnecessary cache misses and generates horrible code. As part of that earlier discussion, we had a much better solution for the NUMA scalability issue - by just making the page lock have a separate contention bit, the waitqueue doesn't even have to be looked at for the normal case. Peter Zijlstra already has a patch for that, but let's see if anybody even notices. In the meantime, let's fix the actual gfs2 breakage by simplifying the bitlock waitqueues and removing the per-zone issue. Reported-by: Andreas Gruenbacher <agruenba@redhat.com> Tested-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-27sched/fair: Remove unused but set variable 'rq'Tobias Klauser1-3/+0
Since commit: 8663e24d56dc ("sched/fair: Reorder cgroup creation code") ... the variable 'rq' in alloc_fair_sched_group() is set but no longer used. Remove it to fix the following GCC warning when building with 'W=1': kernel/sched/fair.c:8842:13: warning: variable ‘rq’ set but not used [-Wunused-but-set-variable] Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161026113704.8981-1-tklauser@distanz.ch Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-25timers: Prevent base clock corruption when forwardingThomas Gleixner1-13/+10
When a timer is enqueued we try to forward the timer base clock. This mechanism has two issues: 1) Forwarding a remote base unlocked The forwarding function is called from get_target_base() with the current timer base lock held. But if the new target base is a different base than the current base (can happen with NOHZ, sigh!) then the forwarding is done on an unlocked base. This can lead to corruption of base->clk. Solution is simple: Invoke the forwarding after the target base is locked. 2) Possible corruption due to jiffies advancing This is similar to the issue in get_net_timer_interrupt() which was fixed in the previous patch. jiffies can advance between check and assignement and therefore advancing base->clk beyond the next expiry value. So we need to read jiffies into a local variable once and do the checks and assignment with the local copy. Fixes: a683f390b93f("timers: Forward the wheel clock whenever possible") Reported-by: Ashton Holmes <scoopta@gmail.com> Reported-by: Michael Thayer <michael.thayer@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Michal Necasek <michal.necasek@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: knut.osmundsen@oracle.com Cc: stable@vger.kernel.org Cc: stern@rowland.harvard.edu Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161022110552.253640125@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-25timers: Prevent base clock rewind when forwarding clockThomas Gleixner1-5/+9
Ashton and Michael reported, that kernel versions 4.8 and later suffer from USB timeouts which are caused by the timer wheel rework. This is caused by a bug in the base clock forwarding mechanism, which leads to timers expiring early. The scenario which leads to this is: run_timers() while (jiffies >= base->clk) { collect_expired_timers(); base->clk++; expire_timers(); } So base->clk = jiffies + 1. Now the cpu goes idle: idle() get_next_timer_interrupt() nextevt = __next_time_interrupt(); if (time_after(nextevt, base->clk)) base->clk = jiffies; jiffies has not advanced since run_timers(), so this assignment effectively decrements base->clk by one. base->clk is the index into the timer wheel arrays. So let's assume the following state after the base->clk increment in run_timers(): jiffies = 0 base->clk = 1 A timer gets enqueued with an expiry delta of 63 ticks (which is the case with the USB timeout and HZ=250) so the resulting bucket index is: base->clk + delta = 1 + 63 = 64 The timer goes into the first wheel level. The array size is 64 so it ends up in bucket 0, which is correct as it takes 63 ticks to advance base->clk to index into bucket 0 again. If the cpu goes idle before jiffies advance, then the bug in the forwarding mechanism sets base->clk back to 0, so the next invocation of run_timers() at the next tick will index into bucket 0 and therefore expire the timer 62 ticks too early. Instead of blindly setting base->clk to jiffies we must make the forwarding conditional on jiffies > base->clk, but we cannot use jiffies for this as we might run into the following issue: if (time_after(jiffies, base->clk) { if (time_after(nextevt, base->clk)) base->clk = jiffies; jiffies can increment between the check and the assigment far enough to advance beyond nextevt. So we need to use a stable value for checking. get_next_timer_interrupt() has the basej argument which is the jiffies value snapshot taken in the calling code. So we can just that. Thanks to Ashton for bisecting and providing trace data! Fixes: a683f390b93f ("timers: Forward the wheel clock whenever possible") Reported-by: Ashton Holmes <scoopta@gmail.com> Reported-by: Michael Thayer <michael.thayer@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Michal Necasek <michal.necasek@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: knut.osmundsen@oracle.com Cc: stable@vger.kernel.org Cc: stern@rowland.harvard.edu Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161022110552.175308322@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-25timers: Lock base for same bucket optimizationThomas Gleixner1-11/+17
Linus stumbled over the unlocked modification of the timer expiry value in mod_timer() which is an optimization for timers which stay in the same bucket - due to the bucket granularity - despite their expiry time getting updated. The optimization itself still makes sense even if we take the lock, because in case that the bucket stays the same, we avoid the pointless queue/enqueue dance. Make the check and the modification of timer->expires protected by the base lock and shuffle the remaining code around so we can keep the lock held when we actually have to requeue the timer to a different bucket. Fixes: f00c0afdfa62 ("timers: Implement optimization for same expiry time in mod_timer()") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610241711220.4983@nanos Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org>
2016-10-25timers: Plug locking race vs. timer migrationThomas Gleixner1-1/+8
Linus noticed that lock_timer_base() lacks a READ_ONCE() for accessing the timer flags. As a consequence the compiler is allowed to reload the flags between the initial check for TIMER_MIGRATION and the following timer base computation and the spin lock of the base. While this has not been observed (yet), we need to make sure that it never happens. Fixes: 0eeda71bc30d ("timer: Replace timer base by a cpu index") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610241711220.4983@nanos Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org>
2016-10-24PM / suspend: Fix missing KERN_CONT for suspend messageJon Hunter1-2/+2
Commit 4bcc595ccd80 (printk: reinstate KERN_CONT for printing continuation lines) exposed a missing KERN_CONT from one of the messages shown on entering suspend. With v4.9-rc1, the 'done.' shown after syncing the filesystems no longer appears as a continuation but a new message with its own timestamp. [ 9.259566] PM: Syncing filesystems ... [ 9.264119] done. Fix this by adding the KERN_CONT log level for the 'done.' part of the message seen after syncing filesystems. While we are at it, convert these suspend printks to pr_info and pr_cont, respectively. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-22Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Ingo Molnar: "Mostly irqchip driver fixes, plus a symbol export" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kernel/irq: Export irq_set_parent() irqchip/gic: Add missing \n to CPU IF adjustment message irqchip/jcore: Don't show Kconfig menu item for driver irqchip/eznps: Drop pointless static qualifier in nps400_of_init() irqchip/gic-v3-its: Fix entry size mask for GITS_BASER irqchip/gic-v3-its: Fix 64bit GIC{R,ITS}_TYPER accesses
2016-10-22softirq: Display IRQ_POLL for irq-poll statisticsSagi Grimberg1-1/+1
This library was moved to the generic area and was renamed to irq-poll. Hence, update proc/softirqs output accordingly. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-21kernel/irq: Export irq_set_parent()Sudip Mukherjee1-0/+1
The TPS65217 driver grew interrupt support which uses irq_set_parent(). While it's not yet clear why this is used in the first place, building the driver as a module fails with: ERROR: ".irq_set_parent" [drivers/mfd/tps65217.ko] undefined! The correctness of the driver change is still investigated, but for now it's less trouble to export irq_set_parent() than dealing with the build wreckage. [ tglx: Rewrote changelog and made the export GPL ] Fixes: 6556bdacf646 ("mfd: tps65217: Add support for IRQs") Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: Marcin Niestroj <m.niestroj@grinn-global.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Lee Jones <lee.jones@linaro.org> Link: http://lkml.kernel.org/r/1475775403-27207-1-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-19Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds1-1/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "This fixes a group scheduling related performance/interactivity regression introduced in v4.8, which affects certain hardware environments where cpu_possible_mask != cpu_present_mask" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix incorrect task group ->load_avg
2016-10-19printk: suppress empty continuation linesLinus Torvalds1-0/+4
We have a fairly common pattern where you print several things as continuations on one single line in a loop, and then at the end you do printk(KERN_CONT "\n"); to flush the buffered output. But if the output was flushed by something else (concurrent printk activity, or just system logging), we don't want that final flushing to just print an empty line. So just suppress empty continuation lines when they couldn't be merged into the line they are a continuation of. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-19Merge branch 'gup_flag-cleanups'Linus Torvalds2-8/+14
Merge the gup_flags cleanups from Lorenzo Stoakes: "This patch series adjusts functions in the get_user_pages* family such that desired FOLL_* flags are passed as an argument rather than implied by flags. The purpose of this change is to make the use of FOLL_FORCE explicit so it is easier to grep for and clearer to callers that this flag is being used. The use of FOLL_FORCE is an issue as it overrides missing VM_READ/VM_WRITE flags for the VMA whose pages we are reading from/writing to, which can result in surprising behaviour. The patch series came out of the discussion around commit 38e088546522 ("mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing"), which addressed a BUG_ON() being triggered when a page was faulted in with PROT_NONE set but having been overridden by FOLL_FORCE. do_numa_page() was run on the assumption the page _must_ be one marked for NUMA node migration as an actual PROT_NONE page would have been dealt with prior to this code path, however FOLL_FORCE introduced a situation where this assumption did not hold. See https://marc.info/?l=linux-mm&m=147585445805166 for the patch proposal" Additionally, there's a fix for an ancient bug related to FOLL_FORCE and FOLL_WRITE by me. [ This branch was rebased recently to add a few more acked-by's and reviewed-by's ] * gup_flag-cleanups: mm: replace access_process_vm() write parameter with gup_flags mm: replace access_remote_vm() write parameter with gup_flags mm: replace __access_remote_vm() write parameter with gup_flags mm: replace get_user_pages_remote() write/force parameters with gup_flags mm: replace get_user_pages() write/force parameters with gup_flags mm: replace get_vaddr_frames() write/force parameters with gup_flags mm: replace get_user_pages_locked() write/force parameters with gup_flags mm: replace get_user_pages_unlocked() write/force parameters with gup_flags mm: remove write/force parameters from __get_user_pages_unlocked() mm: remove write/force parameters from __get_user_pages_locked() mm: remove gup_flags FOLL_WRITE games from __get_user_pages()
2016-10-19mm: replace access_process_vm() write parameter with gup_flagsLorenzo Stoakes1-6/+10
This removes the 'write' argument from access_process_vm() and replaces it with 'gup_flags' as use of this function previously silently implied FOLL_FORCE, whereas after this patch callers explicitly pass this flag. We make this explicit as use of FOLL_FORCE can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-19mm: replace get_user_pages_remote() write/force parameters with gup_flagsLorenzo Stoakes1-2/+4
This removes the 'write' and 'force' from get_user_pages_remote() and replaces them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers as use of this flag can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-19sched/fair: Fix incorrect task group ->load_avgVincent Guittot1-1/+8
A scheduler performance regression has been reported by Joseph Salisbury, which he bisected back to: 3d30544f0212 ("sched/fair: Apply more PELT fixes) The regression triggers when several levels of task groups are involved (read: SystemD) and cpu_possible_mask != cpu_present_mask. The root cause is that group entity's load (tg_child->se[i]->avg.load_avg) is initialized to scale_load_down(se->load.weight). During the creation of a child task group, its group entities on possible CPUs are attached to parent's cfs_rq (tg_parent) and their loads are added to the parent's load (tg_parent->load_avg) with update_tg_load_avg(). But only the load on online CPUs will then be updated to reflect real load, whereas load on other CPUs will stay at the initial value. The result is a tg_parent->load_avg that is higher than the real load, the weight of group entities (tg_parent->se[i]->load.weight) on online CPUs is smaller than it should be, and the task group gets a less running time than what it could expect. ( This situation can be detected with /proc/sched_debug. The ".tg_load_avg" of the task group will be much higher than sum of ".tg_load_avg_contrib" of online cfs_rqs of the task group. ) The load of group entities don't have to be intialized to something else than 0 because their load will increase when an entity is attached. Reported-by: Joseph Salisbury <joseph.salisbury@canonical.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@vger.kernel.org> # 4.8.x Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: joonwoop@codeaurora.org Fixes: 3d30544f0212 ("sched/fair: Apply more PELT fixes) Link: http://lkml.kernel.org/r/1476881123-10159-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-18Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixlet from Ingo Molnar: "Remove an unused variable" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: alarmtimer: Remove unused but set variable
2016-10-18Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds1-3/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "Fix a crash that can trigger when racing with CPU hotplug: we didn't use sched-domains data structures carefully enough in select_idle_cpu()" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix sched domains NULL dereference in select_idle_sibling()
2016-10-18Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc fixes from Ingo Molnar: "A CPU hotplug debuggability fix and three objtool false positive warnings fixes for new GCC6 code generation patterns" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Use distinct name for cpu_hotplug.dep_map objtool: Skip all "unreachable instruction" warnings for gcov kernels objtool: Improve rare switch jump table pattern detection objtool: Support '-mtune=atom' stack frame setup instruction
2016-10-17alarmtimer: Remove unused but set variableTobias Klauser1-2/+0
Remove the set but unused variable base in alarm_clock_get to fix the following warning when building with 'W=1': kernel/time/alarmtimer.c: In function ‘alarm_timer_create’: kernel/time/alarmtimer.c:545:21: warning: variable ‘base’ set but not used [-Wunused-but-set-variable] Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20161017094702.10873-1-tklauser@distanz.ch Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-16cpu/hotplug: Use distinct name for cpu_hotplug.dep_mapJoonas Lahtinen1-1/+1
Use distinctive name for cpu_hotplug.dep_map to avoid the actual cpu_hotplug.lock appearing as cpu_hotplug.lock#2 in lockdep splats. Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Gautham R . Shenoy <ego@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: intel-gfx@lists.freedesktop.org Cc: trivial@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-15Merge tag 'gcc-plugins-v4.9-rc1' of ↵Linus Torvalds6-8/+11
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull gcc plugins update from Kees Cook: "This adds a new gcc plugin named "latent_entropy". It is designed to extract as much possible uncertainty from a running system at boot time as possible, hoping to capitalize on any possible variation in CPU operation (due to runtime data differences, hardware differences, SMP ordering, thermal timing variation, cache behavior, etc). At the very least, this plugin is a much more comprehensive example for how to manipulate kernel code using the gcc plugin internals" * tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: latent_entropy: Mark functions with __latent_entropy gcc-plugins: Add latent_entropy plugin
2016-10-14Merge branch 'for-4.9' of ↵Linus Torvalds3-34/+57
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - tracepoints for basic cgroup management operations added - kernfs and cgroup path formatting functions updated to behave in the style of strlcpy() - non-critical bug fixes * 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: blkcg: Unlock blkcg_pol_mutex only once when cpd == NULL cgroup: fix error handling regressions in proc_cgroup_show() and cgroup_release_agent() cpuset: fix error handling regression in proc_cpuset_show() cgroup: add tracepoints for basic operations cgroup: make cgroup_path() and friends behave in the style of strlcpy() kernfs: remove kernfs_path_len() kernfs: make kernfs_path*() behave in the style of strlcpy() kernfs: add dummy implementation of kernfs_path_from_node()
2016-10-12Disable the __builtin_return_address() warning globally after allLinus Torvalds1-4/+0
This affectively reverts commit 377ccbb48373 ("Makefile: Mute warning for __builtin_return_address(>0) for tracing only") because it turns out that it really isn't tracing only - it's all over the tree. We already also had the warning disabled separately for mm/usercopy.c (which this commit also removes), and it turns out that we will also want to disable it for get_lock_parent_ip(), that is used for at least TRACE_IRQFLAGS. Which (when enabled) ends up being all over the tree. Steven Rostedt had a patch that tried to limit it to just the config options that actually triggered this, but quite frankly, the extra complexity and abstraction just isn't worth it. We have never actually had a case where the warning is actually useful, so let's just disable it globally and not worry about it. Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-12hung_task: allow hung_task_panic when hung_task_warnings is 0John Siddle1-14/+14
Previously hung_task_panic would not be respected if enabled after hung_task_warnings had already been decremented to 0. Permit the kernel to panic if hung_task_panic is enabled after hung_task_warnings has already been decremented to 0 and another task hangs for hung_task_timeout_secs seconds. Check if hung_task_panic is enabled so we don't return prematurely, and check if hung_task_warnings is non-zero so we don't print the warning unnecessarily. [akpm@linux-foundation.org: fix off-by-one] Link: http://lkml.kernel.org/r/1473450214-4049-1-git-send-email-jsiddle@redhat.com Signed-off-by: John Siddle <jsiddle@redhat.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-12kthread: better support freezable kthread workersPetr Mladek1-6/+15
This patch allows to make kthread worker freezable via a new @flags parameter. It will allow to avoid an init work in some kthreads. It currently does not affect the function of kthread_worker_fn() but it might help to do some optimization or fixes eventually. I currently do not know about any other use for the @flags parameter but I believe that we will want more flags in the future. Finally, I hope that it will not cause confusion with @flags member in struct kthread. Well, I guess that we will want to rework the basic kthreads implementation once all kthreads are converted into kthread workers or workqueues. It is possible that we will merge the two structures. Link: http://lkml.kernel.org/r/1470754545-17632-12-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-12kthread: allow to modify delayed kthread workPetr Mladek1-0/+53
There are situations when we need to modify the delay of a delayed kthread work. For example, when the work depends on an event and the initial delay means a timeout. Then we want to queue the work immediately when the event happens. This patch implements kthread_mod_delayed_work() as inspired workqueues. It cancels the timer, removes the work from any worker list and queues it again with the given timeout. A very special case is when the work is being canceled at the same time. It might happen because of the regular kthread_cancel_delayed_work_sync() or by another kthread_mod_delayed_work(). In this case, we do nothing and let the other operation win. This should not normally happen as the caller is supposed to synchronize these operations a reasonable way. Link: http://lkml.kernel.org/r/1470754545-17632-11-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>