Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Linus Torvalds e56b3bc794 cpu masks: optimize and clean up cpumask_of_cpu() ... Clean up and optimize cpumask_of_cpu(), by sharing all the zero words. Instead of stupidly generating all possible i=0...NR_CPUS 2^i patterns creating a huge array of constant bitmasks, realize that the zero words can be shared. In other words, on a 64-bit architecture, we only ever need 64 of these arrays - with a different bit set in one single world (with enough zero words around it so that we can create any bitmask by just offsetting in that big array). And then we just put enough zeroes around it that we can point every single cpumask to be one of those things. So when we have 4k CPU's, instead of having 4k arrays (of 4k bits each, with one bit set in each array - 2MB memory total), we have exactly 64 arrays instead, each 8k bits in size (64kB total). And then we just point cpumask(n) to the right position (which we can calculate dynamically). Once we have the right arrays, getting "cpumask(n)" ends up being: static inline const cpumask_t *get_cpu_mask(unsigned int cpu) { const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; p -= cpu / BITS_PER_LONG; return (const cpumask_t *)p; } This brings other advantages and simplifications as well: - we are not wasting memory that is just filled with a single bit in various different places - we don't need all those games to re-create the arrays in some dense format, because they're already going to be dense enough. if we compile a kernel for up to 4k CPU's, "wasting" that 64kB of memory is a non-issue (especially since by doing this "overlapping" trick we probably get better cache behaviour anyway). [ mingo@elte.hu: Converted Linus's mails into a commit. See: http://lkml.org/lkml/2008/7/27/156 http://lkml.org/lkml/2008/7/28/320 Also applied a family filter - which also has the side-effect of leaving out the bits where Linus calls me an idio... Oh, never mind ;-) ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2008-07-28 22:20:41 +02:00
..
irq	use WARN() in kernel/irq/chip.c	2008-07-26 12:00:07 -07:00
power	kexec jump: save/restore device state	2008-07-26 12:00:04 -07:00
time	cpumask: change cpumask_of_cpu_ptr to use new cpumask_of_cpu	2008-07-26 16:40:33 +02:00
trace	Merge branch 'linus' into cpus4096	2008-07-28 21:14:43 +02:00
.gitignore	Update kernel/.gitignore with new auto-generated files	2008-02-09 23:27:01 -08:00
acct.c	bsdacct: fix and add comments around acct_process()	2008-07-25 10:53:47 -07:00
audit.c	[PATCH] remove useless argument type in audit_filter_user()	2008-06-24 23:36:35 -04:00
audit.h	[PATCH 1/2] audit: move extern declarations to audit.h	2008-04-28 06:28:04 -04:00
audit_tree.c	[PATCH] list_for_each_rcu must die: audit	2008-05-17 03:30:23 -04:00
auditfilter.c	[PATCH] remove useless argument type in audit_filter_user()	2008-06-24 23:36:35 -04:00
auditsc.c	x86_64 syscall audit fast-path	2008-07-23 17:47:32 -07:00
backtracetest.c	backtrace: replace timer with tasklet + completions	2008-06-27 18:09:16 +02:00
bounds.c	Add kbuild.h that contains common definitions for kbuild users	2008-04-29 08:06:29 -07:00
capability.c	security: filesystem capabilities refactor kernel code	2008-07-24 10:47:22 -07:00
cgroup.c	[PATCH] get rid of indirect users of namei.h	2008-07-26 20:53:42 -04:00
cgroup_debug.c	CGroup API files: move "releasable" to cgroup_debug subsystem	2008-04-29 08:06:09 -07:00
compat.c	ntp: support for TAI	2008-05-01 08:03:59 -07:00
configs.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
cpu.c	cpu masks: optimize and clean up cpumask_of_cpu()	2008-07-28 22:20:41 +02:00
cpuset.c	cpuset: two minor code-cleanups	2008-07-25 10:53:38 -07:00
delayacct.c	per-task-delay-accounting: update taskstats for memory reclaim delay	2008-07-25 10:53:47 -07:00
dma.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
exec_domain.c	[PATCH] kill altroot	2008-07-26 20:53:20 -04:00
exit.c	task IO accounting: improve code readability	2008-07-27 09:58:20 -07:00
extable.c	module: Don't report discarded init pages as kernel text.	2008-01-29 17:13:18 +11:00
fork.c	task IO accounting: improve code readability	2008-07-27 09:58:20 -07:00
futex.c	futexes: fix fault handling in futex_lock_pi	2008-06-23 13:31:15 +02:00
futex_compat.c	futex_compat __user annotation	2008-03-30 14:18:41 -07:00
hrtimer.c	Merge branch 'generic-ipi' into generic-ipi-for-linus	2008-07-15 21:55:59 +02:00
itimer.c	ITIMER_REAL: convert to use struct pid	2008-02-08 09:22:29 -08:00
kallsyms.c	kallsyms: fix potential overflow in binary search	2008-07-25 10:53:27 -07:00
Kconfig.hz	sched: fix hrtick & generic-ipi dependency	2008-07-23 11:18:28 +02:00
Kconfig.preempt	rcu: move PREEMPT_RCU config option back under PREEMPT	2008-03-10 18:01:20 -07:00
kexec.c	kexec jump: save/restore device state	2008-07-26 12:00:04 -07:00
kfifo.c
kgdb.c	kgdb: sparse fix	2008-06-24 10:52:55 -05:00
kmod.c	call_usermodehelper(): increase reliability	2008-07-25 10:53:28 -07:00
kprobes.c	kprobes: remove redundant config check	2008-07-25 10:53:30 -07:00
ksysfs.c	Kobject: convert remaining kobject_unregister() to kobject_put()	2008-01-24 20:40:40 -08:00
kthread.c	tracehook: wait_task_inactive	2008-07-26 12:00:09 -07:00
latencytop.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
lockdep.c	Merge branch 'core/locking' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2008-07-14 14:55:13 -07:00
lockdep_internals.h	lockdep: add lock_class information to lock_chain and output it	2008-06-24 01:28:20 +02:00
lockdep_proc.c	lockdep: add lock_class information to lock_chain and output it	2008-06-24 01:28:20 +02:00
Makefile	build kernel/profile.o only when requested	2008-07-25 10:53:27 -07:00
marker.c	markers: use rcu_barrier_sched() and call_rcu_sched()	2008-07-25 10:53:45 -07:00
module.c	modules: Take a shortcut for checking if an address is in a module	2008-07-22 19:24:28 +10:00
mutex-debug.c	mutex-debug: check mutex magic before owner	2008-05-16 16:53:35 +02:00
mutex-debug.h
mutex.c	__mutex_lock_common: use signal_pending_state()	2008-06-10 11:45:09 +02:00
mutex.h
notifier.c	ipc: re-enable msgmni automatic recomputing msgmni if set to negative	2008-04-29 08:06:13 -07:00
ns_cgroup.c	cgroup_clone: use pid of newly created task for new cgroup	2008-07-25 10:53:37 -07:00
nsproxy.c	cgroup_clone: use pid of newly created task for new cgroup	2008-07-25 10:53:37 -07:00
panic.c	Add a WARN() macro; this is WARN_ON() + printk arguments	2008-07-25 10:53:29 -07:00
params.c	Add new string functions strict_strto* and convert kernel params to use them	2008-02-08 09:22:41 -08:00
pid.c	pidns: remove now unused find_pid function.	2008-07-25 10:53:45 -07:00
pid_namespace.c	bsdacct: switch from global bsd_acct_struct instance to per-pidns one	2008-07-25 10:53:47 -07:00
pm_qos_params.c	pm_qos_params: BKL pushdown	2008-07-02 15:06:24 -06:00
posix-cpu-timers.c	posix-timers: print RT watchdog message	2008-05-24 18:49:22 +02:00
posix-timers.c	posix timers: release_posix_timer: kill the bogus put_task_struct(->it_process);	2008-07-25 10:53:38 -07:00
printk.c	printk ratelimiting rewrite	2008-07-25 10:53:29 -07:00
profile.c	build kernel/profile.o only when requested	2008-07-25 10:53:27 -07:00
ptrace.c	tracehook: wait_task_inactive	2008-07-26 12:00:09 -07:00
rcuclassic.c	Merge branch 'linus' into cpus4096	2008-07-16 00:29:07 +02:00
rcupdate.c	Merge branch 'generic-ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2008-07-15 14:12:03 -07:00
rcupreempt.c	Merge branch 'linus' into cpus4096	2008-07-16 00:29:07 +02:00
rcupreempt_trace.c	rcu: remove duplicated include in kernel/rcupreempt_trace.c	2008-05-19 10:03:39 +02:00
rcutorture.c	rcu: make rcutorture even more vicious: invoke RCU readers from irq handlers (timers)	2008-06-26 09:24:33 +02:00
relay.c	relay: add buffer-only channels; useful for early logging	2008-07-26 12:00:04 -07:00
res_counter.c	cgroup files: convert res_counter_write() to be a cgroups write_string() handler	2008-07-25 10:53:36 -07:00
resource.c	kernel: use non-racy method for proc entries creation	2008-04-29 08:06:22 -07:00
rtmutex-debug.c	Don't operate with pid_t in rtmutex tester	2008-02-08 09:22:41 -08:00
rtmutex-debug.h
rtmutex-tester.c	sysdev: Pass the attribute to the low level sysdev show/store function	2008-07-21 21:55:02 -07:00
rtmutex.c	hrtimer: more hrtimer_init_sleeper() fallout.	2008-02-13 15:45:36 +01:00
rtmutex.h
rtmutex_common.h	Don't operate with pid_t in rtmutex tester	2008-02-08 09:22:41 -08:00
rwsem.c	sched: mark rwsem functions as __sched for wchan/profiling	2007-12-18 15:21:13 +01:00
sched.c	tracehook: wait_task_inactive	2008-07-26 12:00:09 -07:00
sched_clock.c	Merge branch 'sched/clock' into sched/devel	2008-07-14 12:19:13 +02:00
sched_cpupri.c	sched: use a 2-d bitmap for searching lowest-pri CPU	2008-06-06 15:19:28 +02:00
sched_cpupri.h	sched: fix the cpuprio count really	2008-06-06 15:19:44 +02:00
sched_debug.c	sched: add full schedstats to /proc/sched_debug	2008-06-27 14:31:31 +02:00
sched_fair.c	Merge branch 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2008-07-23 19:36:53 -07:00
sched_features.h	sched: bias effective_load() error towards failing wake_affine().	2008-06-27 14:31:47 +02:00
sched_idletask.c	sched: make rt_sched_class, idle_sched_class static	2008-05-05 23:56:17 +02:00
sched_rt.c	Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2008-07-24 12:53:51 -07:00
sched_stats.h	sched: fix accounting in task delay accounting & migration	2008-07-04 12:50:23 +02:00
seccomp.c
semaphore.c	mmiotrace broken in linux-next (8-bit writes only)	2008-07-01 10:14:06 +02:00
signal.c	tracehook: force signal_pending()	2008-07-26 12:00:09 -07:00
smp.c	Full conversion to early_initcall() interface, remove old interface	2008-07-26 12:00:04 -07:00
softirq.c	Full conversion to early_initcall() interface, remove old interface	2008-07-26 12:00:04 -07:00
softlockup.c	Full conversion to early_initcall() interface, remove old interface	2008-07-26 12:00:04 -07:00
spinlock.c	ftrace: lockdep notrace annotations	2008-05-23 20:39:40 +02:00
srcu.c	make srcu_readers_active() static	2008-02-06 10:41:02 -08:00
stacktrace.c	stacktrace: fix modular build, export print_stack_trace and save_stack_trace	2008-06-30 09:20:55 +02:00
stop_machine.c	cpumask: change cpumask_of_cpu_ptr to use new cpumask_of_cpu	2008-07-26 16:40:33 +02:00
sys.c	kexec jump	2008-07-26 12:00:04 -07:00
sys_ni.c	signalfd: fix undefined reference to `compat_sys_signalfd4' when !CONFIG_SIGNALFD	2008-07-25 11:35:41 -07:00
sysctl.c	lost sysctl fix	2008-07-27 09:45:34 -07:00
sysctl_check.c	sysctl: check for bogus modes	2008-07-25 10:53:45 -07:00
taskstats.c	taskstats: remove initialization of static per-cpu variable	2008-07-25 10:53:47 -07:00
test_kprobes.c	kprobes: kretprobe user entry-handler	2008-02-06 10:41:11 -08:00
time.c	Make constants in kernel/timeconst.h fixed 64 bits	2008-05-02 16:18:42 -07:00
timeconst.pl	Make constants in kernel/timeconst.h fixed 64 bits	2008-05-02 16:18:42 -07:00
timer.c	Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm	2008-07-14 16:06:58 -07:00
tsacct.c	task IO accounting: move all IO statistics in struct task_io_accounting	2008-07-27 16:12:28 -07:00
uid16.c	asmlinkage_protect replaces prevent_tail_call	2008-04-10 17:28:26 -07:00
user.c	alloc_uid: cleanup	2008-04-30 08:29:53 -07:00
user_namespace.c	eCryptfs: make key module subsystem respect namespaces	2008-04-29 08:06:07 -07:00
utsname.c	kernel: explicitly include required header files under kernel/	2008-04-29 08:06:04 -07:00
utsname_sysctl.c
wait.c	kernel: remove fastcall in kernel/*	2008-02-08 09:22:31 -08:00
workqueue.c	workqueues: do CPU_UP_CANCELED if CPU_UP_PREPARE fails	2008-07-25 10:53:41 -07:00