From dfbfdbe2a3efbd7c0d77b0f17a89f39bc5598b2c Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 4 Aug 2014 14:37:58 -0700 Subject: [PATCH] 3.10-stable patches added patches: iio-buffer-fix-demux-table-creation.patch mm-thp-do-not-allow-thp-faults-to-avoid-cpuset-restrictions.patch printk-rename-printk_sched-to-printk_deferred.patch staging-vt6655-fix-disassociated-messages-every-10-seconds.patch timer-fix-lock-inversion-between-hrtimer_bases.lock-and-scheduler-locks.patch --- .../iio-buffer-fix-demux-table-creation.patch | 34 +++ ...-faults-to-avoid-cpuset-restrictions.patch | 80 ++++++ ...name-printk_sched-to-printk_deferred.patch | 89 +++++++ queue-3.10/series | 5 + ...associated-messages-every-10-seconds.patch | 36 +++ ...timer_bases.lock-and-scheduler-locks.patch | 249 ++++++++++++++++++ 6 files changed, 493 insertions(+) create mode 100644 queue-3.10/iio-buffer-fix-demux-table-creation.patch create mode 100644 queue-3.10/mm-thp-do-not-allow-thp-faults-to-avoid-cpuset-restrictions.patch create mode 100644 queue-3.10/printk-rename-printk_sched-to-printk_deferred.patch create mode 100644 queue-3.10/staging-vt6655-fix-disassociated-messages-every-10-seconds.patch create mode 100644 queue-3.10/timer-fix-lock-inversion-between-hrtimer_bases.lock-and-scheduler-locks.patch diff --git a/queue-3.10/iio-buffer-fix-demux-table-creation.patch b/queue-3.10/iio-buffer-fix-demux-table-creation.patch new file mode 100644 index 00000000000..f2e7caf03cf --- /dev/null +++ b/queue-3.10/iio-buffer-fix-demux-table-creation.patch @@ -0,0 +1,34 @@ +From 61bd55ce1667809f022be88da77db17add90ea4e Mon Sep 17 00:00:00 2001 +From: Lars-Peter Clausen +Date: Thu, 17 Jul 2014 16:59:00 +0100 +Subject: iio: buffer: Fix demux table creation + +From: Lars-Peter Clausen + +commit 61bd55ce1667809f022be88da77db17add90ea4e upstream. + +When creating the demux table we need to iterate over the selected scan mask for +the buffer to get the samples which should be copied to destination buffer. +Right now the code uses the mask which contains all active channels, which means +the demux table contains entries which causes it to copy all the samples from +source to destination buffer one by one without doing any demuxing. + +Signed-off-by: Lars-Peter Clausen +Signed-off-by: Jonathan Cameron +Signed-off-by: Greg Kroah-Hartman + +--- + drivers/iio/industrialio-buffer.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/drivers/iio/industrialio-buffer.c ++++ b/drivers/iio/industrialio-buffer.c +@@ -849,7 +849,7 @@ static int iio_buffer_update_demux(struc + + /* Now we have the two masks, work from least sig and build up sizes */ + for_each_set_bit(out_ind, +- indio_dev->active_scan_mask, ++ buffer->scan_mask, + indio_dev->masklength) { + in_ind = find_next_bit(indio_dev->active_scan_mask, + indio_dev->masklength, diff --git a/queue-3.10/mm-thp-do-not-allow-thp-faults-to-avoid-cpuset-restrictions.patch b/queue-3.10/mm-thp-do-not-allow-thp-faults-to-avoid-cpuset-restrictions.patch new file mode 100644 index 00000000000..f650a860348 --- /dev/null +++ b/queue-3.10/mm-thp-do-not-allow-thp-faults-to-avoid-cpuset-restrictions.patch @@ -0,0 +1,80 @@ +From b104a35d32025ca740539db2808aa3385d0f30eb Mon Sep 17 00:00:00 2001 +From: David Rientjes +Date: Wed, 30 Jul 2014 16:08:24 -0700 +Subject: mm, thp: do not allow thp faults to avoid cpuset restrictions + +From: David Rientjes + +commit b104a35d32025ca740539db2808aa3385d0f30eb upstream. + +The page allocator relies on __GFP_WAIT to determine if ALLOC_CPUSET +should be set in allocflags. ALLOC_CPUSET controls if a page allocation +should be restricted only to the set of allowed cpuset mems. + +Transparent hugepages clears __GFP_WAIT when defrag is disabled to prevent +the fault path from using memory compaction or direct reclaim. Thus, it +is unfairly able to allocate outside of its cpuset mems restriction as a +side-effect. + +This patch ensures that ALLOC_CPUSET is only cleared when the gfp mask is +truly GFP_ATOMIC by verifying it is also not a thp allocation. + +Signed-off-by: David Rientjes +Reported-by: Alex Thorlton +Tested-by: Alex Thorlton +Cc: Bob Liu +Cc: Dave Hansen +Cc: Hedi Berriche +Cc: Hugh Dickins +Cc: Johannes Weiner +Cc: Kirill A. Shutemov +Cc: Mel Gorman +Cc: Rik van Riel +Cc: Srivatsa S. Bhat +Signed-off-by: Andrew Morton +Signed-off-by: Linus Torvalds +Signed-off-by: Greg Kroah-Hartman + +--- + mm/page_alloc.c | 16 ++++++++-------- + 1 file changed, 8 insertions(+), 8 deletions(-) + +--- a/mm/page_alloc.c ++++ b/mm/page_alloc.c +@@ -2339,7 +2339,7 @@ static inline int + gfp_to_alloc_flags(gfp_t gfp_mask) + { + int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; +- const gfp_t wait = gfp_mask & __GFP_WAIT; ++ const bool atomic = !(gfp_mask & (__GFP_WAIT | __GFP_NO_KSWAPD)); + + /* __GFP_HIGH is assumed to be the same as ALLOC_HIGH to save a branch. */ + BUILD_BUG_ON(__GFP_HIGH != (__force gfp_t) ALLOC_HIGH); +@@ -2348,20 +2348,20 @@ gfp_to_alloc_flags(gfp_t gfp_mask) + * The caller may dip into page reserves a bit more if the caller + * cannot run direct reclaim, or if the caller has realtime scheduling + * policy or is asking for __GFP_HIGH memory. GFP_ATOMIC requests will +- * set both ALLOC_HARDER (!wait) and ALLOC_HIGH (__GFP_HIGH). ++ * set both ALLOC_HARDER (atomic == true) and ALLOC_HIGH (__GFP_HIGH). + */ + alloc_flags |= (__force int) (gfp_mask & __GFP_HIGH); + +- if (!wait) { ++ if (atomic) { + /* +- * Not worth trying to allocate harder for +- * __GFP_NOMEMALLOC even if it can't schedule. ++ * Not worth trying to allocate harder for __GFP_NOMEMALLOC even ++ * if it can't schedule. + */ +- if (!(gfp_mask & __GFP_NOMEMALLOC)) ++ if (!(gfp_mask & __GFP_NOMEMALLOC)) + alloc_flags |= ALLOC_HARDER; + /* +- * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. +- * See also cpuset_zone_allowed() comment in kernel/cpuset.c. ++ * Ignore cpuset mems for GFP_ATOMIC rather than fail, see the ++ * comment for __cpuset_node_allowed_softwall(). + */ + alloc_flags &= ~ALLOC_CPUSET; + } else if (unlikely(rt_task(current)) && !in_interrupt()) diff --git a/queue-3.10/printk-rename-printk_sched-to-printk_deferred.patch b/queue-3.10/printk-rename-printk_sched-to-printk_deferred.patch new file mode 100644 index 00000000000..76eb1b1841c --- /dev/null +++ b/queue-3.10/printk-rename-printk_sched-to-printk_deferred.patch @@ -0,0 +1,89 @@ +From aac74dc495456412c4130a1167ce4beb6c1f0b38 Mon Sep 17 00:00:00 2001 +From: John Stultz +Date: Wed, 4 Jun 2014 16:11:40 -0700 +Subject: printk: rename printk_sched to printk_deferred + +From: John Stultz + +commit aac74dc495456412c4130a1167ce4beb6c1f0b38 upstream. + +After learning we'll need some sort of deferred printk functionality in +the timekeeping core, Peter suggested we rename the printk_sched function +so it can be reused by needed subsystems. + +This only changes the function name. No logic changes. + +Signed-off-by: John Stultz +Reviewed-by: Steven Rostedt +Cc: Jan Kara +Cc: Peter Zijlstra +Cc: Jiri Bohac +Cc: Thomas Gleixner +Cc: Ingo Molnar +Signed-off-by: Andrew Morton +Signed-off-by: Linus Torvalds +Signed-off-by: Greg Kroah-Hartman + +--- + include/linux/printk.h | 6 +++--- + kernel/printk.c | 2 +- + kernel/sched/core.c | 2 +- + kernel/sched/rt.c | 2 +- + 4 files changed, 6 insertions(+), 6 deletions(-) + +--- a/include/linux/printk.h ++++ b/include/linux/printk.h +@@ -124,9 +124,9 @@ asmlinkage __printf(1, 2) __cold + int printk(const char *fmt, ...); + + /* +- * Special printk facility for scheduler use only, _DO_NOT_USE_ ! ++ * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ ! + */ +-__printf(1, 2) __cold int printk_sched(const char *fmt, ...); ++__printf(1, 2) __cold int printk_deferred(const char *fmt, ...); + + /* + * Please don't use printk_ratelimit(), because it shares ratelimiting state +@@ -161,7 +161,7 @@ int printk(const char *s, ...) + return 0; + } + static inline __printf(1, 2) __cold +-int printk_sched(const char *s, ...) ++int printk_deferred(const char *s, ...) + { + return 0; + } +--- a/kernel/printk.c ++++ b/kernel/printk.c +@@ -2485,7 +2485,7 @@ void wake_up_klogd(void) + preempt_enable(); + } + +-int printk_sched(const char *fmt, ...) ++int printk_deferred(const char *fmt, ...) + { + unsigned long flags; + va_list args; +--- a/kernel/sched/core.c ++++ b/kernel/sched/core.c +@@ -1235,7 +1235,7 @@ out: + * leave kernel. + */ + if (p->mm && printk_ratelimit()) { +- printk_sched("process %d (%s) no longer affine to cpu%d\n", ++ printk_deferred("process %d (%s) no longer affine to cpu%d\n", + task_pid_nr(p), p->comm, cpu); + } + } +--- a/kernel/sched/rt.c ++++ b/kernel/sched/rt.c +@@ -892,7 +892,7 @@ static int sched_rt_runtime_exceeded(str + + if (!once) { + once = true; +- printk_sched("sched: RT throttling activated\n"); ++ printk_deferred("sched: RT throttling activated\n"); + } + } else { + /* diff --git a/queue-3.10/series b/queue-3.10/series index 4d35536722f..b2f9d636796 100644 --- a/queue-3.10/series +++ b/queue-3.10/series @@ -3,3 +3,8 @@ arm-8115-1-lpae-reduce-damage-caused-by-idmap-to-virtual-memory-layout.patch cfg80211-fix-mic_failure-tracing.patch rapidio-tsi721_dma-fix-failure-to-obtain-transaction-descriptor.patch scsi-handle-flush-errors-properly.patch +mm-thp-do-not-allow-thp-faults-to-avoid-cpuset-restrictions.patch +staging-vt6655-fix-disassociated-messages-every-10-seconds.patch +iio-buffer-fix-demux-table-creation.patch +printk-rename-printk_sched-to-printk_deferred.patch +timer-fix-lock-inversion-between-hrtimer_bases.lock-and-scheduler-locks.patch diff --git a/queue-3.10/staging-vt6655-fix-disassociated-messages-every-10-seconds.patch b/queue-3.10/staging-vt6655-fix-disassociated-messages-every-10-seconds.patch new file mode 100644 index 00000000000..4fde201f772 --- /dev/null +++ b/queue-3.10/staging-vt6655-fix-disassociated-messages-every-10-seconds.patch @@ -0,0 +1,36 @@ +From 4aa0abed3a2a11b7d71ad560c1a3e7631c5a31cd Mon Sep 17 00:00:00 2001 +From: Malcolm Priestley +Date: Wed, 23 Jul 2014 21:35:12 +0100 +Subject: staging: vt6655: Fix disassociated messages every 10 seconds + +From: Malcolm Priestley + +commit 4aa0abed3a2a11b7d71ad560c1a3e7631c5a31cd upstream. + +byReAssocCount is incremented every second resulting in +disassociated message being send every 10 seconds whether +connection or not. + +byReAssocCount should only advance while eCommandState +is in WLAN_ASSOCIATE_WAIT + +Change existing scope to if condition. + +Signed-off-by: Malcolm Priestley +Signed-off-by: Greg Kroah-Hartman + +--- + drivers/staging/vt6655/bssdb.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/drivers/staging/vt6655/bssdb.c ++++ b/drivers/staging/vt6655/bssdb.c +@@ -1026,7 +1026,7 @@ start: + pDevice->byERPFlag &= ~(WLAN_SET_ERP_USE_PROTECTION(1)); + } + +- { ++ if (pDevice->eCommandState == WLAN_ASSOCIATE_WAIT) { + pDevice->byReAssocCount++; + if ((pDevice->byReAssocCount > 10) && (pDevice->bLinkPass != true)) { //10 sec timeout + printk("Re-association timeout!!!\n"); diff --git a/queue-3.10/timer-fix-lock-inversion-between-hrtimer_bases.lock-and-scheduler-locks.patch b/queue-3.10/timer-fix-lock-inversion-between-hrtimer_bases.lock-and-scheduler-locks.patch new file mode 100644 index 00000000000..4690c410173 --- /dev/null +++ b/queue-3.10/timer-fix-lock-inversion-between-hrtimer_bases.lock-and-scheduler-locks.patch @@ -0,0 +1,249 @@ +From 504d58745c9ca28d33572e2d8a9990b43e06075d Mon Sep 17 00:00:00 2001 +From: Jan Kara +Date: Fri, 1 Aug 2014 12:20:02 +0200 +Subject: timer: Fix lock inversion between hrtimer_bases.lock and scheduler locks + +From: Jan Kara + +commit 504d58745c9ca28d33572e2d8a9990b43e06075d upstream. + +clockevents_increase_min_delta() calls printk() from under +hrtimer_bases.lock. That causes lock inversion on scheduler locks because +printk() can call into the scheduler. Lockdep puts it as: + +====================================================== +[ INFO: possible circular locking dependency detected ] +3.15.0-rc8-06195-g939f04b #2 Not tainted +------------------------------------------------------- +trinity-main/74 is trying to acquire lock: + (&port_lock_key){-.....}, at: [<811c60be>] serial8250_console_write+0x8c/0x10c + +but task is already holding lock: + (hrtimer_bases.lock){-.-...}, at: [<8103caeb>] hrtimer_try_to_cancel+0x13/0x66 + +which lock already depends on the new lock. + +the existing dependency chain (in reverse order) is: + +-> #5 (hrtimer_bases.lock){-.-...}: + [<8104a942>] lock_acquire+0x92/0x101 + [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e + [<8103c918>] __hrtimer_start_range_ns+0x1c/0x197 + [<8107ec20>] perf_swevent_start_hrtimer.part.41+0x7a/0x85 + [<81080792>] task_clock_event_start+0x3a/0x3f + [<810807a4>] task_clock_event_add+0xd/0x14 + [<8108259a>] event_sched_in+0xb6/0x17a + [<810826a2>] group_sched_in+0x44/0x122 + [<81082885>] ctx_sched_in.isra.67+0x105/0x11f + [<810828e6>] perf_event_sched_in.isra.70+0x47/0x4b + [<81082bf6>] __perf_install_in_context+0x8b/0xa3 + [<8107eb8e>] remote_function+0x12/0x2a + [<8105f5af>] smp_call_function_single+0x2d/0x53 + [<8107e17d>] task_function_call+0x30/0x36 + [<8107fb82>] perf_install_in_context+0x87/0xbb + [<810852c9>] SYSC_perf_event_open+0x5c6/0x701 + [<810856f9>] SyS_perf_event_open+0x17/0x19 + [<8142f8ee>] syscall_call+0x7/0xb + +-> #4 (&ctx->lock){......}: + [<8104a942>] lock_acquire+0x92/0x101 + [<8142f04c>] _raw_spin_lock+0x21/0x30 + [<81081df3>] __perf_event_task_sched_out+0x1dc/0x34f + [<8142cacc>] __schedule+0x4c6/0x4cb + [<8142cae0>] schedule+0xf/0x11 + [<8142f9a6>] work_resched+0x5/0x30 + +-> #3 (&rq->lock){-.-.-.}: + [<8104a942>] lock_acquire+0x92/0x101 + [<8142f04c>] _raw_spin_lock+0x21/0x30 + [<81040873>] __task_rq_lock+0x33/0x3a + [<8104184c>] wake_up_new_task+0x25/0xc2 + [<8102474b>] do_fork+0x15c/0x2a0 + [<810248a9>] kernel_thread+0x1a/0x1f + [<814232a2>] rest_init+0x1a/0x10e + [<817af949>] start_kernel+0x303/0x308 + [<817af2ab>] i386_start_kernel+0x79/0x7d + +-> #2 (&p->pi_lock){-.-...}: + [<8104a942>] lock_acquire+0x92/0x101 + [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e + [<810413dd>] try_to_wake_up+0x1d/0xd6 + [<810414cd>] default_wake_function+0xb/0xd + [<810461f3>] __wake_up_common+0x39/0x59 + [<81046346>] __wake_up+0x29/0x3b + [<811b8733>] tty_wakeup+0x49/0x51 + [<811c3568>] uart_write_wakeup+0x17/0x19 + [<811c5dc1>] serial8250_tx_chars+0xbc/0xfb + [<811c5f28>] serial8250_handle_irq+0x54/0x6a + [<811c5f57>] serial8250_default_handle_irq+0x19/0x1c + [<811c56d8>] serial8250_interrupt+0x38/0x9e + [<810510e7>] handle_irq_event_percpu+0x5f/0x1e2 + [<81051296>] handle_irq_event+0x2c/0x43 + [<81052cee>] handle_level_irq+0x57/0x80 + [<81002a72>] handle_irq+0x46/0x5c + [<810027df>] do_IRQ+0x32/0x89 + [<8143036e>] common_interrupt+0x2e/0x33 + [<8142f23c>] _raw_spin_unlock_irqrestore+0x3f/0x49 + [<811c25a4>] uart_start+0x2d/0x32 + [<811c2c04>] uart_write+0xc7/0xd6 + [<811bc6f6>] n_tty_write+0xb8/0x35e + [<811b9beb>] tty_write+0x163/0x1e4 + [<811b9cd9>] redirected_tty_write+0x6d/0x75 + [<810b6ed6>] vfs_write+0x75/0xb0 + [<810b7265>] SyS_write+0x44/0x77 + [<8142f8ee>] syscall_call+0x7/0xb + +-> #1 (&tty->write_wait){-.....}: + [<8104a942>] lock_acquire+0x92/0x101 + [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e + [<81046332>] __wake_up+0x15/0x3b + [<811b8733>] tty_wakeup+0x49/0x51 + [<811c3568>] uart_write_wakeup+0x17/0x19 + [<811c5dc1>] serial8250_tx_chars+0xbc/0xfb + [<811c5f28>] serial8250_handle_irq+0x54/0x6a + [<811c5f57>] serial8250_default_handle_irq+0x19/0x1c + [<811c56d8>] serial8250_interrupt+0x38/0x9e + [<810510e7>] handle_irq_event_percpu+0x5f/0x1e2 + [<81051296>] handle_irq_event+0x2c/0x43 + [<81052cee>] handle_level_irq+0x57/0x80 + [<81002a72>] handle_irq+0x46/0x5c + [<810027df>] do_IRQ+0x32/0x89 + [<8143036e>] common_interrupt+0x2e/0x33 + [<8142f23c>] _raw_spin_unlock_irqrestore+0x3f/0x49 + [<811c25a4>] uart_start+0x2d/0x32 + [<811c2c04>] uart_write+0xc7/0xd6 + [<811bc6f6>] n_tty_write+0xb8/0x35e + [<811b9beb>] tty_write+0x163/0x1e4 + [<811b9cd9>] redirected_tty_write+0x6d/0x75 + [<810b6ed6>] vfs_write+0x75/0xb0 + [<810b7265>] SyS_write+0x44/0x77 + [<8142f8ee>] syscall_call+0x7/0xb + +-> #0 (&port_lock_key){-.....}: + [<8104a62d>] __lock_acquire+0x9ea/0xc6d + [<8104a942>] lock_acquire+0x92/0x101 + [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e + [<811c60be>] serial8250_console_write+0x8c/0x10c + [<8104e402>] call_console_drivers.constprop.31+0x87/0x118 + [<8104f5d5>] console_unlock+0x1d7/0x398 + [<8104fb70>] vprintk_emit+0x3da/0x3e4 + [<81425f76>] printk+0x17/0x19 + [<8105bfa0>] clockevents_program_min_delta+0x104/0x116 + [<8105c548>] clockevents_program_event+0xe7/0xf3 + [<8105cc1c>] tick_program_event+0x1e/0x23 + [<8103c43c>] hrtimer_force_reprogram+0x88/0x8f + [<8103c49e>] __remove_hrtimer+0x5b/0x79 + [<8103cb21>] hrtimer_try_to_cancel+0x49/0x66 + [<8103cb4b>] hrtimer_cancel+0xd/0x18 + [<8107f102>] perf_swevent_cancel_hrtimer.part.60+0x2b/0x30 + [<81080705>] task_clock_event_stop+0x20/0x64 + [<81080756>] task_clock_event_del+0xd/0xf + [<81081350>] event_sched_out+0xab/0x11e + [<810813e0>] group_sched_out+0x1d/0x66 + [<81081682>] ctx_sched_out+0xaf/0xbf + [<81081e04>] __perf_event_task_sched_out+0x1ed/0x34f + [<8142cacc>] __schedule+0x4c6/0x4cb + [<8142cae0>] schedule+0xf/0x11 + [<8142f9a6>] work_resched+0x5/0x30 + +other info that might help us debug this: + +Chain exists of: + &port_lock_key --> &ctx->lock --> hrtimer_bases.lock + + Possible unsafe locking scenario: + + CPU0 CPU1 + ---- ---- + lock(hrtimer_bases.lock); + lock(&ctx->lock); + lock(hrtimer_bases.lock); + lock(&port_lock_key); + + *** DEADLOCK *** + +4 locks held by trinity-main/74: + #0: (&rq->lock){-.-.-.}, at: [<8142c6f3>] __schedule+0xed/0x4cb + #1: (&ctx->lock){......}, at: [<81081df3>] __perf_event_task_sched_out+0x1dc/0x34f + #2: (hrtimer_bases.lock){-.-...}, at: [<8103caeb>] hrtimer_try_to_cancel+0x13/0x66 + #3: (console_lock){+.+...}, at: [<8104fb5d>] vprintk_emit+0x3c7/0x3e4 + +stack backtrace: +CPU: 0 PID: 74 Comm: trinity-main Not tainted 3.15.0-rc8-06195-g939f04b #2 + 00000000 81c3a310 8b995c14 81426f69 8b995c44 81425a99 8161f671 8161f570 + 8161f538 8161f559 8161f538 8b995c78 8b142bb0 00000004 8b142fdc 8b142bb0 + 8b995ca8 8104a62d 8b142fac 000016f2 81c3a310 00000001 00000001 00000003 +Call Trace: + [<81426f69>] dump_stack+0x16/0x18 + [<81425a99>] print_circular_bug+0x18f/0x19c + [<8104a62d>] __lock_acquire+0x9ea/0xc6d + [<8104a942>] lock_acquire+0x92/0x101 + [<811c60be>] ? serial8250_console_write+0x8c/0x10c + [<811c6032>] ? wait_for_xmitr+0x76/0x76 + [<8142f11d>] _raw_spin_lock_irqsave+0x2e/0x3e + [<811c60be>] ? serial8250_console_write+0x8c/0x10c + [<811c60be>] serial8250_console_write+0x8c/0x10c + [<8104af87>] ? lock_release+0x191/0x223 + [<811c6032>] ? wait_for_xmitr+0x76/0x76 + [<8104e402>] call_console_drivers.constprop.31+0x87/0x118 + [<8104f5d5>] console_unlock+0x1d7/0x398 + [<8104fb70>] vprintk_emit+0x3da/0x3e4 + [<81425f76>] printk+0x17/0x19 + [<8105bfa0>] clockevents_program_min_delta+0x104/0x116 + [<8105cc1c>] tick_program_event+0x1e/0x23 + [<8103c43c>] hrtimer_force_reprogram+0x88/0x8f + [<8103c49e>] __remove_hrtimer+0x5b/0x79 + [<8103cb21>] hrtimer_try_to_cancel+0x49/0x66 + [<8103cb4b>] hrtimer_cancel+0xd/0x18 + [<8107f102>] perf_swevent_cancel_hrtimer.part.60+0x2b/0x30 + [<81080705>] task_clock_event_stop+0x20/0x64 + [<81080756>] task_clock_event_del+0xd/0xf + [<81081350>] event_sched_out+0xab/0x11e + [<810813e0>] group_sched_out+0x1d/0x66 + [<81081682>] ctx_sched_out+0xaf/0xbf + [<81081e04>] __perf_event_task_sched_out+0x1ed/0x34f + [<8104416d>] ? __dequeue_entity+0x23/0x27 + [<81044505>] ? pick_next_task_fair+0xb1/0x120 + [<8142cacc>] __schedule+0x4c6/0x4cb + [<81047574>] ? trace_hardirqs_off_caller+0xd7/0x108 + [<810475b0>] ? trace_hardirqs_off+0xb/0xd + [<81056346>] ? rcu_irq_exit+0x64/0x77 + +Fix the problem by using printk_deferred() which does not call into the +scheduler. + +Reported-by: Fengguang Wu +Signed-off-by: Jan Kara +Signed-off-by: Thomas Gleixner +Signed-off-by: Greg Kroah-Hartman + +--- + kernel/time/clockevents.c | 10 ++++++---- + 1 file changed, 6 insertions(+), 4 deletions(-) + +--- a/kernel/time/clockevents.c ++++ b/kernel/time/clockevents.c +@@ -138,7 +138,8 @@ static int clockevents_increase_min_delt + { + /* Nothing to do if we already reached the limit */ + if (dev->min_delta_ns >= MIN_DELTA_LIMIT) { +- printk(KERN_WARNING "CE: Reprogramming failure. Giving up\n"); ++ printk_deferred(KERN_WARNING ++ "CE: Reprogramming failure. Giving up\n"); + dev->next_event.tv64 = KTIME_MAX; + return -ETIME; + } +@@ -151,9 +152,10 @@ static int clockevents_increase_min_delt + if (dev->min_delta_ns > MIN_DELTA_LIMIT) + dev->min_delta_ns = MIN_DELTA_LIMIT; + +- printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n", +- dev->name ? dev->name : "?", +- (unsigned long long) dev->min_delta_ns); ++ printk_deferred(KERN_WARNING ++ "CE: %s increased min_delta_ns to %llu nsec\n", ++ dev->name ? dev->name : "?", ++ (unsigned long long) dev->min_delta_ns); + return 0; + } + -- 2.47.3