2bbb6817c0
It is assumed that rcu won't be used once we switch to tickless mode and until we restart the tick. However this is not always true, as in x86-64 where we dereference the idle notifiers after the tick is stopped. To prepare for fixing this, add two new APIs: tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu(). If no use of RCU is made in the idle loop between tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch must instead call the new *_norcu() version such that the arch doesn't need to call rcu_idle_enter() and rcu_idle_exit(). Otherwise the arch must call tick_nohz_enter_idle() and tick_nohz_exit_idle() and also call explicitly: - rcu_idle_enter() after its last use of RCU before the CPU is put to sleep. - rcu_idle_exit() before the first use of RCU after the CPU is woken up. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> |
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.. | ||
asm-offsets.c | ||
clock.c | ||
cpu-ucv2.c | ||
debug-macro.S | ||
debug.S | ||
dma.c | ||
early_printk.c | ||
elf.c | ||
entry.S | ||
fpu-ucf64.c | ||
gpio.c | ||
head.S | ||
hibernate_asm.S | ||
hibernate.c | ||
init_task.c | ||
irq.c | ||
ksyms.c | ||
ksyms.h | ||
Makefile | ||
module.c | ||
pci.c | ||
pm.c | ||
process.c | ||
ptrace.c | ||
puv3-core.c | ||
puv3-nb0916.c | ||
pwm.c | ||
setup.c | ||
setup.h | ||
signal.c | ||
sleep.S | ||
stacktrace.c | ||
sys.c | ||
time.c | ||
traps.c | ||
vmlinux.lds.S |