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Steven Rostedt d1a291437f tracing: Use kmem_cache_alloc instead of kmalloc in trace_events.c 
The event structures used by the trace events are mostly persistent,
but they are also allocated by kmalloc, which is not the best at
allocating space for what is used. By converting these kmallocs
into kmem_cache_allocs, we can save over 50K of space that is
permanently allocated.

After boot we have:

 slab name          active allocated size
 ---------          ------ --------- ----
ftrace_event_file    979   1005     56   67    1
ftrace_event_field   2301   2310     48   77    1

The ftrace_event_file has at boot up 979 active objects out of
1005 allocated in the slabs. Each object is 56 bytes. In a normal
kmalloc, that would allocate 64 bytes for each object.

 1005 - 979  = 26 objects not used
 26 * 56 = 1456 bytes wasted

But if we used kmalloc:

 64 - 56 = 8 bytes unused per allocation
 8 * 979 = 7832 bytes wasted

 7832 - 1456 = 6376 bytes in savings

Doing the same for ftrace_event_field where there's 2301 objects
allocated in a slab that can hold 2310 with 48 bytes each we have:

 2310 - 2301 = 9 objects not used
 9 * 48 = 432 bytes wasted

A kmalloc would also use 64 bytes per object:

 64 - 48 = 16 bytes unused per allocation
 16 * 2301 = 36816 bytes wasted!

 36816 - 432 = 36384 bytes in savings

This change gives us a total of 42760 bytes in savings. At least
on my machine, but as there's a lot of these persistent objects
for all configurations that use trace points, this is a net win.

Thanks to Ezequiel Garcia for his trace_analyze presentation which
pointed out the wasted space in my code.

Cc: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
 		2013-03-15 00:34:46 -04:00
..
debug module: add new state MODULE_STATE_UNFORMED. 2013-01-12 13:27:05 +10:30
events Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 17:49:41 -08:00
gcov
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irq Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:07:27 -08:00
power Merge branch 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2012-12-12 08:18:24 -08:00
sched Merge branch 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2013-02-19 22:01:33 -08:00
time Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:05:45 -08:00
trace tracing: Use kmem_cache_alloc instead of kmalloc in trace_events.c 2013-03-15 00:34:46 -04:00
.gitignore
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Kconfig.freezer
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Kconfig.hz
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Kconfig.locks locking: Adjust spin lock inlining Kconfig options 2012-09-13 17:56:13 +02:00
Kconfig.preempt locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage 2012-03-23 13:18:57 +01:00
Makefile Nothing all that exciting; a new module-from-fd syscall for those who want 2012-12-19 07:55:08 -08:00
acct.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
async.c Merge branch 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2013-02-19 22:01:33 -08:00
audit.c kernel/audit.c: avoid negative sleep durations 2013-01-11 14:54:56 -08:00
audit.h audit: optimize audit_compare_dname_path 2012-10-12 00:32:02 -04:00
audit_tree.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
audit_watch.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
auditfilter.c audit: fix auditfilter.c kernel-doc warnings 2013-01-10 14:35:23 -08:00
auditsc.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
backtracetest.c
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bounds.c
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capability.c userns: Teach inode_capable to understand inodes whose uids map to other namespaces. 2012-05-15 14:59:24 -07:00
cgroup.c Merge branch 'akpm' (Andrew's patch-bomb) 2012-12-17 20:58:12 -08:00
cgroup_freezer.c cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free() 2012-11-19 08:13:38 -08:00
compat.c x32: fix sigtimedwait 2012-12-26 01:15:03 -05:00
configs.c
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context_tracking.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
cpu.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:04:55 -08:00
cpu_pm.c kernel/cpu_pm.c: fix various typos 2012-05-31 17:49:27 -07:00
cpuset.c cpuset: use N_MEMORY instead N_HIGH_MEMORY 2012-12-12 17:38:32 -08:00
crash_dump.c
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cred.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-18 10:55:28 -08:00
delayacct.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
dma.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
elfcore.c
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exec_domain.c
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exit.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
extable.c extable: Skip sorting if sorted at build time. 2012-04-19 15:06:55 -07:00
fork.c This implements the cputime accounting on full dynticks CPUs. 2013-02-05 13:10:33 +01:00
freezer.c freezer: change ptrace_stop/do_signal_stop to use freezable_schedule() 2012-10-26 14:27:49 -07:00
futex.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
futex_compat.c futex: Mark get_robust_list as deprecated 2012-03-29 11:37:17 +02:00
groups.c userns: Convert in_group_p and in_egroup_p to use kgid_t 2012-05-03 03:29:33 -07:00
hrtimer.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:05:45 -08:00
hung_task.c hung task debugging: Inject NMI when hung and going to panic 2012-04-25 12:39:25 +02:00
irq_work.c Merge branch 'nohz/printk-v8' into irq/core 2013-02-05 00:48:46 +01:00
itimer.c itimer: Use printk_once instead of WARN_ONCE 2012-04-10 11:00:30 +02:00
jump_label.c jump_label: Export jump_label_rate_limit() 2012-08-06 19:00:35 +03:00
kallsyms.c vsprintf: fix %ps on non symbols when using kallsyms 2012-05-29 16:22:32 -07:00
kcmp.c kcmp: include linux/ptrace.h 2012-12-20 17:40:19 -08:00
kexec.c kdump: remove unneeded include 2012-10-06 03:05:19 +09:00
kfifo.c [media] kernel:kfifo: export __kfifo_max_r symbol 2012-04-11 18:24:37 -03:00
kmod.c Merge branch 'master' into for-3.9-async 2013-01-23 09:31:01 -08:00
kprobes.c Merge branch 'for-3.9-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2013-02-19 21:58:52 -08:00
ksysfs.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-12-11 18:10:49 -08:00
kthread.c kthread: use N_MEMORY instead N_HIGH_MEMORY 2012-12-12 17:38:33 -08:00
latencytop.c
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lglock.c brlocks/lglocks: turn into functions 2012-05-29 23:28:41 -04:00
lockdep.c lockdep: Check if nested lock is actually held 2012-09-13 17:00:44 +02:00
lockdep_internals.h
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lockdep_proc.c lockdep: Use KSYM_NAME_LEN'ed buffer for __get_key_name() 2012-10-24 12:39:09 +02:00
lockdep_states.h
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modsign_certificate.S MODSIGN: Avoid using .incbin in C source 2012-12-14 13:06:44 +10:30
modsign_pubkey.c keys: use keyring_alloc() to create module signing keyring 2012-12-20 17:40:21 -08:00
module-internal.h MODSIGN: Move the magic string to the end of a module and eliminate the search 2012-10-19 17:30:40 -07:00
module.c module: fix missing module_mutex unlock 2013-01-20 20:22:58 -08:00
module_signing.c MODSIGN: Don't use enum-type bitfields in module signature info block 2012-12-05 11:27:24 +10:30
mutex-debug.c
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mutex-debug.h
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mutex.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
mutex.h
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notifier.c
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nsproxy.c userns: Implement unshare of the user namespace 2012-11-20 04:18:14 -08:00
padata.c padata: use __this_cpu_read per-cpu helper 2012-12-06 17:16:23 +08:00
panic.c panic: fix a possible deadlock in panic() 2012-07-30 17:25:13 -07:00
params.c params: replace printk(KERN_<LVL>...) with pr_<lvl>(...) 2012-05-04 17:28:18 -07:00
pid.c kernel/pid.c: reenable interrupts when alloc_pid() fails because init has exited 2013-02-12 14:34:00 -08:00
pid_namespace.c pidns: Stop pid allocation when init dies 2012-12-25 16:10:05 -08:00
posix-cpu-timers.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:05:45 -08:00
posix-timers.c posix-timers: Fix clock_adjtime to always return timex data on success 2013-01-15 18:16:07 -08:00
printk.c Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 17:47:58 -08:00
profile.c profiling: Remove unused timer hook 2013-01-24 15:37:26 +01:00
ptrace.c uprobes: Add exports for module use 2013-02-08 17:47:13 +01:00
range.c
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rcu.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcupdate.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutiny.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutiny_plugin.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcutorture.c rcu: Allow rcutorture to be built at low optimization levels 2013-02-04 12:18:20 -08:00
rcutree.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutree.h Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutree_plugin.h rcu: Make rcu_nocb_poll an early_param instead of module_param 2013-01-08 14:12:19 -08:00
rcutree_trace.c rcu: Separate accounting of callbacks from callback-free CPUs 2012-11-16 10:05:57 -08:00
relay.c splice: fix racy pipe->buffers uses 2012-06-13 21:16:42 +02:00
res_counter.c res_counter: return amount of charges after res_counter_uncharge() 2012-12-18 15:02:12 -08:00
resource.c kernel/resource.c: fix stack overflow in __reserve_region_with_split() 2012-10-06 03:05:31 +09:00
rtmutex-debug.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex-debug.h
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rtmutex-tester.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex.h
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rtmutex_common.h
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rwsem.c lockdep, rwsem: provide down_write_nest_lock() 2013-01-11 14:54:55 -08:00
seccomp.c seccomp: Make syscall skipping and nr changes more consistent 2012-10-02 21:14:29 +10:00
semaphore.c semaphore: fix improper comment reference to mutex 2012-04-05 17:15:55 -07:00
signal.c This implements the cputime accounting on full dynticks CPUs. 2013-02-05 13:10:33 +01:00
smp.c smp: Fix SMP function call empty cpu mask race 2013-01-28 11:21:57 +01:00
smpboot.c smpboot: Allow selfparking per cpu threads 2013-02-14 15:29:37 +01:00
smpboot.h smpboot: Provide infrastructure for percpu hotplug threads 2012-08-13 17:01:07 +02:00
softirq.c cputime: Safely read cputime of full dynticks CPUs 2013-01-27 20:35:47 +01:00
spinlock.c locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage 2012-03-23 13:18:57 +01:00
srcu.c srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock() 2013-02-07 15:19:36 -08:00
stacktrace.c
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stop_machine.c stop_machine: Use smpboot threads 2013-02-14 15:29:38 +01:00
sys.c cputime: Rename thread_group_times to thread_group_cputime_adjusted 2012-11-28 17:07:57 +01:00
sys_ni.c module: add syscall to load module from fd 2012-12-14 13:05:22 +10:30
sysctl.c sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice 2013-02-07 20:51:07 +01:00
sysctl_binary.c pidns: Use task_active_pid_ns where appropriate 2012-11-19 05:59:09 -08:00
task_work.c task_work: task_work_add() should not succeed after exit_task_work() 2012-09-13 16:47:34 +02:00
taskstats.c taskstats: cgroupstats_user_cmd() may leak on error 2012-10-06 03:05:31 +09:00
test_kprobes.c
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time.c time, Fix setting of hardware clock in NTP code 2013-02-08 15:07:05 -08:00
timeconst.pl timeconst.pl: Eliminate Perl warning 2013-02-07 17:14:08 -08:00
timer.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
tracepoint.c
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tsacct.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
uid16.c userns: Convert setting and getting uid and gid system calls to use kuid and kgid 2012-05-03 03:28:41 -07:00
up.c
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user-return-notifier.c
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user.c proc: Usable inode numbers for the namespace file descriptors. 2012-11-20 04:19:49 -08:00
user_namespace.c userns: Fix typo in description of the limitation of userns_install 2012-12-14 18:36:36 -08:00
utsname.c userns: Require CAP_SYS_ADMIN for most uses of setns. 2012-12-14 16:12:03 -08:00
utsname_sysctl.c
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wait.c propagate name change to comments in kernel source 2012-12-06 10:39:54 +01:00
watchdog.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
workqueue.c workqueue: un-GPL function delayed_work_timer_fn() 2013-02-19 10:09:13 -08:00
workqueue_internal.h workqueue: rename cpu_workqueue to pool_workqueue 2013-02-13 19:29:12 -08:00