deleted queue-4.0/clockevents-fix-cpu_down-race-for-hrtimer-based-broadcasting.patch

diff --git a/queue-4.0/clockevents-fix-cpu_down-race-for-hrtimer-based-broadcasting.patch b/queue-4.0/clockevents-fix-cpu_down-race-for-hrtimer-based-broadcasting.patch
deleted file mode 100644 (file)
index 4aa49b4..0000000
--- a/queue-4.0/clockevents-fix-cpu_down-race-for-hrtimer-based-broadcasting.patch
+++ /dev/null
@@ -1,150 +0,0 @@
-From 345527b1edce8df719e0884500c76832a18211c3 Mon Sep 17 00:00:00 2001
-From: Preeti U Murthy <preeti@linux.vnet.ibm.com>
-Date: Mon, 30 Mar 2015 14:59:19 +0530
-Subject: clockevents: Fix cpu_down() race for hrtimer based broadcasting
-
-From: Preeti U Murthy <preeti@linux.vnet.ibm.com>
-
-commit 345527b1edce8df719e0884500c76832a18211c3 upstream.
-
-It was found when doing a hotplug stress test on POWER, that the
-machine either hit softlockups or rcu_sched stall warnings.  The
-issue was traced to commit:
-
-  7cba160ad789 ("powernv/cpuidle: Redesign idle states management")
-
-which exposed the cpu_down() race with hrtimer based broadcast mode:
-
-  5d1638acb9f6 ("tick: Introduce hrtimer based broadcast")
-
-The race is the following:
-
-Assume CPU1 is the CPU which holds the hrtimer broadcasting duty
-before it is taken down.
-
-       CPU0                                    CPU1
-
-       cpu_down()                              take_cpu_down()
-                                               disable_interrupts()
-
-       cpu_die()
-
-       while (CPU1 != CPU_DEAD) {
-               msleep(100);
-               switch_to_idle();
-               stop_cpu_timer();
-               schedule_broadcast();
-       }
-
-       tick_cleanup_cpu_dead()
-               take_over_broadcast()
-
-So after CPU1 disabled interrupts it cannot handle the broadcast
-hrtimer anymore, so CPU0 will be stuck forever.
-
-Fix this by explicitly taking over broadcast duty before cpu_die().
-
-This is a temporary workaround. What we really want is a callback
-in the clockevent device which allows us to do that from the dying
-CPU by pushing the hrtimer onto a different cpu. That might involve
-an IPI and is definitely more complex than this immediate fix.
-
-Changelog was picked up from:
-
-    https://lkml.org/lkml/2015/2/16/213
-
-Suggested-by: Thomas Gleixner <tglx@linutronix.de>
-Tested-by: Nicolas Pitre <nico@linaro.org>
-Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
-Cc: linuxppc-dev@lists.ozlabs.org
-Cc: mpe@ellerman.id.au
-Cc: nicolas.pitre@linaro.org
-Cc: peterz@infradead.org
-Cc: rjw@rjwysocki.net
-Fixes: http://linuxppc.10917.n7.nabble.com/offlining-cpus-breakage-td88619.html
-Link: http://lkml.kernel.org/r/20150330092410.24979.59887.stgit@preeti.in.ibm.com
-[ Merged it to the latest timer tree, renamed the callback, tidied up the changelog. ]
-Signed-off-by: Ingo Molnar <mingo@kernel.org>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
-
-Added a hunk that got missed in the previous post.
-Please add this to stable 3.19 and 4.0. The patch applies on both.
-
- include/linux/tick.h         |    7 ++++++-
- kernel/cpu.c                 |    2 ++
- kernel/time/tick-broadcast.c |   19 +++++++++++--------
- 3 files changed, 19 insertions(+), 9 deletions(-)
-
---- a/include/linux/tick.h
-+++ b/include/linux/tick.h
-@@ -100,8 +100,13 @@ extern struct cpumask *tick_get_broadcas
- 
- #  ifdef CONFIG_TICK_ONESHOT
- extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
--#  endif
-+extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu);
-+# else
-+static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
-+#  endif /* TICK_ONESHOT */
- 
-+# else
-+static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
- # endif /* BROADCAST */
- 
- # ifdef CONFIG_TICK_ONESHOT
---- a/kernel/cpu.c
-+++ b/kernel/cpu.c
-@@ -20,6 +20,7 @@
- #include <linux/gfp.h>
- #include <linux/suspend.h>
- #include <linux/lockdep.h>
-+#include <linux/tick.h>
- #include <trace/events/power.h>
- 
- #include "smpboot.h"
-@@ -411,6 +412,7 @@ static int __ref _cpu_down(unsigned int
-       while (!idle_cpu(cpu))
-               cpu_relax();
- 
-+      hotplug_cpu__broadcast_tick_pull(cpu);
-       /* This actually kills the CPU. */
-       __cpu_die(cpu);
- 
---- a/kernel/time/tick-broadcast.c
-+++ b/kernel/time/tick-broadcast.c
-@@ -669,14 +669,19 @@ static void broadcast_shutdown_local(str
-       clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN);
- }
- 
--static void broadcast_move_bc(int deadcpu)
-+void hotplug_cpu__broadcast_tick_pull(int deadcpu)
- {
--      struct clock_event_device *bc = tick_broadcast_device.evtdev;
-+      struct clock_event_device *bc;
-+      unsigned long flags;
-+
-+      raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
-+      bc = tick_broadcast_device.evtdev;
- 
--      if (!bc || !broadcast_needs_cpu(bc, deadcpu))
--              return;
--      /* This moves the broadcast assignment to this cpu */
--      clockevents_program_event(bc, bc->next_event, 1);
-+      if (bc && broadcast_needs_cpu(bc, deadcpu)) {
-+              /* This moves the broadcast assignment to this CPU: */
-+              clockevents_program_event(bc, bc->next_event, 1);
-+      }
-+      raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
- }
- 
- /*
-@@ -913,8 +918,6 @@ void tick_shutdown_broadcast_oneshot(uns
-       cpumask_clear_cpu(cpu, tick_broadcast_pending_mask);
-       cpumask_clear_cpu(cpu, tick_broadcast_force_mask);
- 
--      broadcast_move_bc(cpu);
--
-       raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
- }
- 

diff --git a/queue-4.0/series b/queue-4.0/series
index 3e369342f1abdb7d03b302fb49661baee2aad570..64219abedf5bc0c643efd6ab0db410fb38e66678 100644 (file)
--- a/queue-4.0/series
+++ b/queue-4.0/series
@@ -70,4 +70,3 @@ drm-radeon-reset-bos-address-after-clearing-it.patch
 drm-radeon-check-new-address-before-removing-old-one.patch
 hfsplus-don-t-store-special-osx-xattr-prefix-on-disk.patch
 drivers-hv-vmbus-don-t-wait-after-requesting-offers.patch
-clockevents-fix-cpu_down-race-for-hrtimer-based-broadcasting.patch