1
linux/kernel
Eric Dumazet 1c69d921ed [PATCH] rcu: add a prefetch() in rcu_do_batch()
On some workloads, (for example when lot of close() syscalls are done), RCU
qlen can be quite large, and RCU heads are no longer in cpu cache when
rcu_do_batch() is called.

This patch adds a prefetch() in rcu_do_batch() to give CPU a hint to bring
back cache lines containing 'struct rcu_head's.

Most list manipulations macros include prefetch(), but not open coded ones
(at least with current C compilers :) )

I got a nice speedup on a trivial benchmark (3.48 us per iteration instead
of 3.95 us on a 1.6 GHz Pentium-M)

while (1) { pipe(p); close(fd[0]); close(fd[1]);}

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:40 -08:00
..
irq [PATCH] lockdep: name some old style locks 2006-12-07 08:39:36 -08:00
power [PATCH] Export pm_suspend for the shared APM emulation 2006-12-07 08:39:32 -08:00
time [PATCH] time_adjust cleared before use 2006-10-28 11:30:55 -07:00
.gitignore
acct.c [PATCH] lockdep: name some old style locks 2006-12-07 08:39:36 -08:00
audit.c [PATCH] Add include/linux/freezer.h and move definitions from sched.h 2006-12-07 08:39:27 -08:00
audit.h
auditfilter.c [PATCH] arch filter lists with < or > should not be accepted 2006-10-04 08:31:16 -04:00
auditsc.c [PATCH] severing skbuff.h -> highmem.h 2006-12-04 02:00:29 -05:00
capability.c [PATCH] pidspace: is_init() 2006-09-29 09:18:12 -07:00
compat.c [PATCH] Create compat_sys_migrate_pages 2006-11-03 12:27:59 -08:00
configs.c
cpu.c [PATCH] suspend: don't change cpus_allowed for task initiating the suspend 2006-12-07 08:39:28 -08:00
cpuset.c [PATCH] hotplug CPU: clean up hotcpu_notifier() use 2006-12-07 08:39:39 -08:00
delayacct.c [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
dma.c [PATCH] kernel-doc for kernel/dma.c 2006-10-03 08:03:41 -07:00
exec_domain.c
exit.c [PATCH] taskstats: cleanup do_exit() path 2006-12-07 08:39:34 -08:00
extable.c
fork.c [PATCH] taskstats: cleanup ->signal->stats allocation 2006-12-07 08:39:34 -08:00
futex_compat.c [PATCH] __user annotations: futex 2006-10-10 15:37:22 -07:00
futex.c [PATCH] mm: pagefault_{disable,enable}() 2006-12-07 08:39:21 -08:00
hrtimer.c [PATCH] posix-timers: Fix clock_nanosleep() doesn't return the remaining time in compatibility mode 2006-09-29 09:18:15 -07:00
itimer.c
kallsyms.c [PATCH] /proc/kallsyms reports lower-case types for some non-exported symbols 2006-12-07 08:39:31 -08:00
Kconfig.hz [PATCH] HZ: 300Hz support 2006-12-07 08:39:36 -08:00
Kconfig.preempt
kexec.c [PATCH] kexec warning fix 2006-09-29 09:18:15 -07:00
kfifo.c [PATCH] memory ordering in __kfifo primitives 2006-09-29 09:18:13 -07:00
kmod.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2006-12-05 14:37:56 +00:00
kprobes.c [PATCH] kprobes: enable booster on the preemptible kernel 2006-12-07 08:39:38 -08:00
ksysfs.c
kthread.c WorkStruct: Pass the work_struct pointer instead of context data 2006-11-22 14:55:48 +00:00
latency.c [PATCH] severing module.h->sched.h 2006-12-04 02:00:22 -05:00
lockdep_internals.h
lockdep_proc.c
lockdep.c [PATCH] remove kernel/lockdep.c:lockdep_internal 2006-12-07 08:39:39 -08:00
Makefile [PATCH] srcu-3: RCU variant permitting read-side blocking 2006-10-04 07:55:30 -07:00
module.c [PATCH] severing module.h->sched.h 2006-12-04 02:00:22 -05:00
mutex-debug.c Lockdep: add lockdep_set_class_and_subclass() and lockdep_set_subclass() 2006-10-11 01:45:14 -04:00
mutex-debug.h
mutex.c
mutex.h
nsproxy.c [PATCH] kernel/nsproxy.c: use kmemdup() 2006-10-20 10:26:44 -07:00
panic.c [PATCH] x86: Clean up x86 NMI sysctls 2006-09-30 01:47:55 +02:00
params.c [PATCH] module_subsys: initialize earlier 2006-09-29 09:18:08 -07:00
pid.c [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
posix-cpu-timers.c [PATCH] posix-cpu-timers: prevent signal delivery starvation 2006-10-17 08:18:43 -07:00
posix-timers.c [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
printk.c [PATCH] remove the syslog interface when printk is disabled 2006-12-07 08:39:38 -08:00
profile.c [PATCH] hotplug CPU: clean up hotcpu_notifier() use 2006-12-07 08:39:39 -08:00
ptrace.c [PATCH] pidspace: is_init() 2006-09-29 09:18:12 -07:00
rcupdate.c [PATCH] rcu: add a prefetch() in rcu_do_batch() 2006-12-07 08:39:40 -08:00
rcutorture.c [PATCH] rcu: add sched torture type to rcutorture 2006-10-04 07:55:31 -07:00
relay.c WorkStruct: make allyesconfig 2006-11-22 14:57:56 +00:00
resource.c [PATCH] kernel-doc for kernel/resource.c 2006-10-03 08:03:41 -07:00
rtmutex_common.h
rtmutex-debug.c Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
rtmutex-debug.h
rtmutex-tester.c [PATCH] Add include/linux/freezer.h and move definitions from sched.h 2006-12-07 08:39:27 -08:00
rtmutex.c [PATCH] clean up and remove some extra spinlocks from rtmutex 2006-09-29 09:18:09 -07:00
rtmutex.h
rwsem.c
sched.c [PATCH] hotplug CPU: clean up hotcpu_notifier() use 2006-12-07 08:39:39 -08:00
seccomp.c
signal.c [PATCH] make kernel/signal.c:kill_proc_info() static 2006-12-07 08:39:39 -08:00
softirq.c [PATCH] check return value of cpu_callback 2006-09-29 09:18:14 -07:00
softlockup.c [PATCH] check return value of cpu_callback 2006-09-29 09:18:14 -07:00
spinlock.c [PATCH] lockdep: spin_lock_irqsave_nested() 2006-11-25 13:28:34 -08:00
srcu.c [PATCH] SRCU: report out-of-memory errors 2006-10-04 07:55:30 -07:00
stacktrace.c
stop_machine.c [PATCH] stop_machine.c copyright 2006-09-29 09:18:24 -07:00
sys_ni.c [PATCH] Create compat_sys_migrate_pages 2006-11-03 12:27:59 -08:00
sys.c WorkStruct: Pass the work_struct pointer instead of context data 2006-11-22 14:55:48 +00:00
sysctl.c [PATCH] new scheme to preempt swap token 2006-12-07 08:39:21 -08:00
taskstats.c [PATCH] taskstats: cleanup reply assembling 2006-12-07 08:39:34 -08:00
time.c [PATCH] NTP: Move all the NTP related code to ntp.c 2006-10-01 00:39:26 -07:00
timer.c [PATCH] kill wall_jiffies 2006-10-01 00:39:27 -07:00
tsacct.c [PATCH] xacct_add_tsk: fix pure theoretical ->mm use-after-free 2006-10-30 12:08:41 -08:00
uid16.c
unwind.c [PATCH] x86-64: work around gcc4 issue with -Os in Dwarf2 stack unwind 2006-11-28 20:12:59 +01:00
user.c [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
utsname.c [PATCH] namespaces: utsname: implement CLONE_NEWUTS flag 2006-10-02 07:57:22 -07:00
wait.c
workqueue.c [PATCH] hotplug CPU: clean up hotcpu_notifier() use 2006-12-07 08:39:39 -08:00