5 files changed, 208 insertions, 0 deletions

diff --git a/recipes-kernel/linux/files/patches/nohz-Drop-generic-vtime-obsolete-dependency-on-CONFI.patch b/recipes-kernel/linux/files/patches/nohz-Drop-generic-vtime-obsolete-dependency-on-CONFI.patch
new file mode 100644
index 0000000..4c0fb89
--- /dev/null
+++ b/recipes-kernel/linux/files/patches/nohz-Drop-generic-vtime-obsolete-dependency-on-CONFI.patch
@@ -0,0 +1,50 @@
+From 3b2566af2c0ef888f95920f69e9a7e0ebc13ddff Mon Sep 17 00:00:00 2001
+From: Kevin Hilman <khilman@linaro.org>
+Date: Mon, 16 Sep 2013 15:28:19 -0700
+Subject: [PATCH] nohz: Drop generic vtime obsolete dependency on CONFIG_64BIT
+
+The CONFIG_64BIT requirement on vtime can finally be removed
+since we now depend on HAVE_VIRT_CPU_ACCOUNTING_GEN which
+already takes care of the arch ability to handle nsecs based
+cputime_t safely.
+
+Signed-off-by: Kevin Hilman <khilman@linaro.org>
+Cc: Ingo Molnar <mingo@kernel.org>
+Cc: Russell King <rmk@arm.linux.org.uk>
+Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
+Cc: Arm Linux <linux-arm-kernel@lists.infradead.org>
+Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
+Signed-off-by: Mats Liljegren <mats.liljegren@enea.com>
+---
+ init/Kconfig        | 2 +-
+ kernel/time/Kconfig | 1 -
+ 2 files changed, 1 insertion(+), 2 deletions(-)
+
+diff --git a/init/Kconfig b/init/Kconfig
+index 0b5d0c8..d7411e5 100644
+--- a/init/Kconfig
++++ b/init/Kconfig
+@@ -325,7 +325,7 @@ config VIRT_CPU_ACCOUNTING_NATIVE
+ 
+ config VIRT_CPU_ACCOUNTING_GEN
+        bool "Full dynticks CPU time accounting"
+-       depends on HAVE_CONTEXT_TRACKING && 64BIT
++       depends on HAVE_CONTEXT_TRACKING
+        select VIRT_CPU_ACCOUNTING
+        select CONTEXT_TRACKING
+        help
+diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
+index 70f27e8..c270b48 100644
+--- a/kernel/time/Kconfig
++++ b/kernel/time/Kconfig
+@@ -100,7 +100,6 @@ config NO_HZ_FULL
+        # RCU_USER_QS dependency
+        depends on HAVE_CONTEXT_TRACKING
+        # VIRT_CPU_ACCOUNTING_GEN dependency
+-       depends on 64BIT
+        select NO_HZ_COMMON
+        select RCU_USER_QS
+        select RCU_NOCB_CPU
+-- 
+1.9.1
+
diff --git a/recipes-kernel/linux/files/patches/sched-nohz-Fix-overflow-error-in-scheduler_tick_max_.patch b/recipes-kernel/linux/files/patches/sched-nohz-Fix-overflow-error-in-scheduler_tick_max_.patch
new file mode 100644
index 0000000..c279422
--- /dev/null
+++ b/recipes-kernel/linux/files/patches/sched-nohz-Fix-overflow-error-in-scheduler_tick_max_.patch
@@ -0,0 +1,76 @@
+From 189a149dfc3ab55282b38d2194a0d7def74d8dfa Mon Sep 17 00:00:00 2001
+From: Kevin Hilman <khilman@linaro.org>
+Date: Wed, 15 Jan 2014 14:51:38 +0100
+Subject: [PATCH] sched/nohz: Fix overflow error in
+ scheduler_tick_max_deferment()
+
+While calculating the scheduler tick max deferment, the delta is
+converted from microseconds to nanoseconds through a multiplication
+against NSEC_PER_USEC.
+
+But this microseconds operand is an unsigned int, thus the result may
+likely overflow. The result is cast to u64 but only once the operation
+is completed, which is too late to avoid overflown result.
+
+This is currently not a problem because the scheduler tick max deferment
+is 1 second. But this may become an issue as we plan to make this
+value tunable.
+
+So lets fix this by casting the usecs value to u64 before multiplying by
+NSECS_PER_USEC.
+
+Also to prevent from this kind of mistake to happen again, move this
+ad-hoc jiffies -> nsecs conversion to a new helper.
+
+Signed-off-by: Kevin Hilman <khilman@linaro.org>
+Cc: Thomas Gleixner <tglx@linutronix.de>
+Cc: Ingo Molnar <mingo@kernel.org>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Alex Shi <alex.shi@linaro.org>
+Cc: Steven Rostedt <rostedt@goodmis.org>
+Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
+Cc: John Stultz <john.stultz@linaro.org>
+Cc: Kevin Hilman <khilman@linaro.org>
+Link: http://lkml.kernel.org/r/1387315388-31676-2-git-send-email-khilman@linaro.org
+[move ad-hoc conversion to jiffies_to_nsecs helper]
+Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
+
+Signed-off-by: Mats Liljegren <mats.liljegren@enea.com>
+---
+ include/linux/jiffies.h | 6 ++++++
+ kernel/sched/core.c     | 2 +-
+ 2 files changed, 7 insertions(+), 1 deletion(-)
+
+diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
+index 8fb8edf..4df91d4 100644
+--- a/include/linux/jiffies.h
++++ b/include/linux/jiffies.h
+@@ -290,6 +290,12 @@ extern unsigned long preset_lpj;
+  */
+ extern unsigned int jiffies_to_msecs(const unsigned long j);
+ extern unsigned int jiffies_to_usecs(const unsigned long j);
++
++static inline u64 jiffies_to_nsecs(const unsigned long j)
++{
++       return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC;
++}
++
+ extern unsigned long msecs_to_jiffies(const unsigned int m);
+ extern unsigned long usecs_to_jiffies(const unsigned int u);
+ extern unsigned long timespec_to_jiffies(const struct timespec *value);
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index e8b3350..45c2cf1 100644
+--- a/kernel/sched/core.c
++++ b/kernel/sched/core.c
+@@ -2774,7 +2774,7 @@ u64 scheduler_tick_max_deferment(void)
+        if (time_before_eq(next, now))
+                return 0;
+ 
+-       return jiffies_to_usecs(next - now) * NSEC_PER_USEC;
++       return jiffies_to_nsecs(next - now);
+ }
+ #endif
+ 
+-- 
+1.9.1
+
diff --git a/recipes-kernel/linux/files/patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch b/recipes-kernel/linux/files/patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch
new file mode 100644
index 0000000..349604c
--- /dev/null
+++ b/recipes-kernel/linux/files/patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch
@@ -0,0 +1,61 @@
+From 92f0d4f695198fcb935cf0360f93a15bf0a6af1e Mon Sep 17 00:00:00 2001
+From: Kevin Hilman <khilman@linaro.org>
+Date: Mon, 16 Sep 2013 15:43:48 -0700
+Subject: [PATCH 3/3] sched/nohz: add debugfs control over
+ sched_tick_max_deferment
+
+Allow debugfs override of sched_tick_max_deferment in order to ease
+finding/fixing the remaining issues with full nohz.
+
+The value to be written is in jiffies, and -1 means the max deferment
+is disabled (scheduler_tick_max_deferment() returns KTIME_MAX.)
+
+Cc: Frederic Weisbecker <fweisbec@gmail.com>
+Signed-off-by: Kevin Hilman <khilman@linaro.org>
+---
+ kernel/sched/core.c |   16 +++++++++++++++-
+ 1 file changed, 15 insertions(+), 1 deletion(-)
+
+diff --git a/kernel/sched/core.c b/kernel/sched/core.c
+index e8b3350..59c7367 100644
+--- a/kernel/sched/core.c
++++ b/kernel/sched/core.c
+@@ -2753,6 +2753,8 @@ void scheduler_tick(void)
+ }
+ 
+ #ifdef CONFIG_NO_HZ_FULL
++static u32 sched_tick_max_deferment = HZ;
++
+ /**
+  * scheduler_tick_max_deferment
+  *
+@@ -2769,13 +2771,25 @@ u64 scheduler_tick_max_deferment(void)
+        struct rq *rq = this_rq();
+        unsigned long next, now = ACCESS_ONCE(jiffies);
+ 
+-       next = rq->last_sched_tick + HZ;
++       if (sched_tick_max_deferment == -1)
++               return KTIME_MAX;
++
++       next = rq->last_sched_tick + sched_tick_max_deferment;
+ 
+        if (time_before_eq(next, now))
+                return 0;
+ 
+        return jiffies_to_usecs(next - now) * NSEC_PER_USEC;
+ }
++
++static __init int sched_nohz_full_init_debug(void)
++{
++       debugfs_create_u32("sched_tick_max_deferment", 0644, NULL,
++                          &sched_tick_max_deferment);
++
++       return 0;
++}
++late_initcall(sched_nohz_full_init_debug);
+ #endif
+ 
+ notrace unsigned long get_parent_ip(unsigned long addr)
+-- 
+1.7.10.4
+
diff --git a/recipes-kernel/linux/linux-keystone_3.10.bbappend b/recipes-kernel/linux/linux-keystone_3.10.bbappend
new file mode 100644
index 0000000..b7f72dc
--- /dev/null
+++ b/recipes-kernel/linux/linux-keystone_3.10.bbappend
@@ -0,0 +1,12 @@
+FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
+
+SRC_URI += "\
+        file://cfg/00039-nohz.cfg \
+        file://patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch \
+        file://patches/sched-nohz-Fix-overflow-error-in-scheduler_tick_max_.patch \
+        file://patches/nohz-Drop-generic-vtime-obsolete-dependency-on-CONFI.patch \
+        "
+
+KERNEL_FEATURES += " \
+        cfg/00039-nohz \
+        "
diff --git a/recipes-kernel/linux/linux-yocto_3.10.bbappend b/recipes-kernel/linux/linux-yocto_3.10.bbappend
new file mode 100644
index 0000000..c7365b1
--- /dev/null
+++ b/recipes-kernel/linux/linux-yocto_3.10.bbappend
@@ -0,0 +1,9 @@
+FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
+
+SRC_URI += "\
+        file://cfg/00038-hotplug_cpu.cfg \
+        file://cfg/00039-nohz.cfg \
+        file://patches/sched-nohz-add-debugfs-control-over-sched_tick_max_d.patch \
+        file://patches/sched-nohz-Fix-overflow-error-in-scheduler_tick_max_.patch \
+        file://patches/nohz-Drop-generic-vtime-obsolete-dependency-on-CONFI.patch \
+        "