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From: Andrew Morton <akpm@linux-foundation.org>
To: Valdis.Kletnieks@vt.edu
Cc: andi@firstfloor.org, linux-kernel@vger.kernel.org
Subject: Re: 2.6.25-rc3-mm1 - PROFILE_LIKELY redux..
Date: Wed, 5 Mar 2008 15:49:42 -0800	[thread overview]
Message-ID: <20080305154942.a8dae04d.akpm@linux-foundation.org> (raw)
In-Reply-To: <5762.1204755985@turing-police.cc.vt.edu>

On Wed, 05 Mar 2008 17:26:25 -0500
Valdis.Kletnieks@vt.edu wrote:

> On Wed, 05 Mar 2008 10:02:21 PST, Andrew Morton said:
> 
> > at the top, so it'll be something else.  Perhaps a `likely' snuck in via an
> > inline in a header file.  It would be better to add a #define DONT_DO_THAT
> > at the top of arch/x86/kernel/vsyscall_64.c and
> > arch/x86/vdso/vclock_gettime.c, then use that to defeat likely-profiling.
> > 
> >  arch/x86/kernel/vsyscall_64.c  |   11 ++---------
> >  arch/x86/vdso/vclock_gettime.c |   11 ++---------
> >  include/linux/compiler.h       |    3 ++-
> >  3 files changed, 6 insertions(+), 19 deletions(-)
> 
> Confirming that this patch works and my system goes multi-user cleanly.

Thanks.

> Actual numbers after about 10 minutes of uptime:
> 
> % wc -l /proc/likely_prof 
> 2635 /proc/likely_prof
> % grep '^[^ ]' /proc/likely_prof 
> Likely Profiling Results
> [+- ] Type | # True | # False | Function:Filename@Line
> +unlikely |        1|        0  in_dev_get()@:include/linux/inetdevice.h@185
> +unlikely |      513|        0  dst_input()@:include/net/dst.h@254
> -likely   |        0|      148  ip6_mc_input()@:net/ipv6/ip6_input.c@271
> -likely   |        0|        1  sock_error()@:include/net/sock.h@1211
> -likely   |      851|     1219  tcp_transmit_skb()@:net/ipv4/tcp_output.c@493
> +unlikely |        1|        0  signal_pending()@:include/linux/sched.h@1927
> -likely   |        0|  1172946  audit_syscall_entry()@:kernel/auditsc.c@1522
> +unlikely |  1172716|        0  syscall_trace_enter()@:arch/x86/kernel/ptrace.c@1556
> -likely   |        0|  1173020  audit_syscall_exit()@:kernel/auditsc.c@1551
> +unlikely |  1172831|        0  syscall_trace_leave()@:arch/x86/kernel/ptrace.c@1573
> -likely   |        0|     1272  audit_alloc()@:kernel/auditsc.c@841
> +unlikely |        3|        0  icmp_unreach()@:net/ipv4/icmp.c@773
> +unlikely |        2|        1  nf_ct_attach()@:net/netfilter/core.c@230
> -likely   |        0|        2  dst_gc_task()@:net/core/dst.c@82
> +unlikely |      143|       61  fput_light()@:include/linux/file.h@77
> +unlikely |      892|      424  _read_unlock_irqrestore()@:kernel/spinlock.c@375
> +unlikely |       28|        0  sched_move_task()@:kernel/sched.c@7835
> +unlikely |       28|        0  sched_move_task()@:kernel/sched.c@7828
> +unlikely |      108|        0  verify_export_symbols()@:kernel/module.c@1401
> +unlikely |      313|        0  verify_export_symbols()@:kernel/module.c@1393
> +unlikely |       14|        0  ll_front_merge_fn()@:block/blk-merge.c@347
> -likely   |       17|     1150  audit_free()@:kernel/auditsc.c@1428
> -likely   |       17|  1174290  audit_get_context()@:kernel/auditsc.c@711
> +unlikely |       33|        0  inotify_find_update_watch()@:fs/inotify.c@591
> +unlikely |     4360|      775  kill_pid_info()@:kernel/signal.c@1065
> +unlikely |     7239|     2767  next_pidmap()@:kernel/pid.c@194
> +unlikely |    42009|    33683  copy_pte_range()@:mm/memory.c@510
> -likely   |        0|        1  qh_completions()@:drivers/usb/host/ehci-q.c@368
> +unlikely |    19934|        0  ll_back_merge_fn()@:block/blk-merge.c@309
> -likely   |      927|     2323  load_elf_binary()@:fs/binfmt_elf.c@896
> +unlikely |     2435|      875  pmd_alloc()@:include/linux/mm.h@862
> +unlikely |       13|       12  psmouse_interrupt()@:drivers/input/mouse/psmouse-base.c@296
> +unlikely |       70|       25  psmouse_interrupt()@:drivers/input/mouse/psmouse-base.c@292
> -likely   |       20|       80  qh_completions()@:drivers/usb/host/ehci-q.c@415
> -likely   |        0|       30  qh_completions()@:drivers/usb/host/ehci-q.c@319
> -likely   |        5|       14  submit_async()@:drivers/usb/host/ehci-q.c@975
> +unlikely |       19|        2  qh_append_tds()@:drivers/usb/host/ehci-q.c@876
> -likely   |        6|       15  atapi_drain_needed()@:drivers/ata/libata-scsi.c@846
> +unlikely |    27395|    18153  add_timer_randomness()@:drivers/char/random.c@628
> +unlikely |    34665|    19948  bio_phys_segments()@:fs/bio.c@226
> -likely   |      347|      678  clocksource_adjust()@:kernel/time/timekeeping.c@418
> -likely   |        1|        4  __ata_qc_from_tag()@:include/linux/libata.h@1319
> -likely   |        0|       15  __cancel_work_timer()@:kernel/workqueue.c@490
> +unlikely |    15638|     1127  queue_delayed_work_on()@:kernel/workqueue.c@233
> +unlikely |        2|        0  srcu_notifier_chain_register()@:kernel/notifier.c@419
> +unlikely |     6502|     2429  queue_work()@:kernel/workqueue.c@171
> +unlikely |        9|        2  blocking_notifier_chain_register()@:kernel/notifier.c@212
> +unlikely |    13631|        0  pre_schedule_rt()@:kernel/sched_rt.c@961
> +unlikely |   591400|   443725  __update_curr()@:kernel/sched_fair.c@313
> +unlikely |   233625|   205658  __switch_to()@:arch/x86/kernel/process_64.c@656
> +unlikely |   313057|   126225  __switch_to()@:arch/x86/kernel/process_64.c@641
> +unlikely |   313053|   126225  __switch_to()@:arch/x86/kernel/process_64.c@637
> +unlikely |   467383|        0  sched_info_switch()@:kernel/sched_stats.h@230
> +unlikely |   188448|    13628  pick_next_task_rt()@:kernel/sched_rt.c@522
> +unlikely |   240619|        0  sched_info_queued()@:kernel/sched_stats.h@188
> -likely   |       61|      644  ifind()@:fs/inode.c@798
> +unlikely |   258562|    61703  scheduler_tick()@:kernel/sched.c@3756
> -likely   |    61220|   241529  acct_update_integrals()@:kernel/tsacct.c@120
> +unlikely |  1189922|   902477  kfree()@:mm/slab.c@3785
> +unlikely |       23|        0  __rmqueue_fallback()@:mm/page_alloc.c@812
> +unlikely |    14376|     9655  rt_policy()@:kernel/sched.c@140

These are all the ones which we got wrong on your setup, yes?

I wonder if assuming that current->audit_context is NULL is realistic
nowadays.


  reply	other threads:[~2008-03-05 23:50 UTC|newest]

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-04  9:19 2.6.25-rc3-mm1 Andrew Morton
2008-03-04 11:59 ` 2.6.25-rc3-mm1 Cornelia Huck
2008-03-04 19:35   ` 2.6.25-rc3-mm1 Greg KH
2008-03-04 13:12 ` [BUG] 2.6.25-rc3-mm1 kernel panic while bootup on powerpc () Kamalesh Babulal
2008-03-04 14:40   ` Michael Neuling
2008-03-04 18:33     ` Andrew Morton
2008-03-05  8:23       ` Benjamin Herrenschmidt
2008-03-06  0:03       ` Benjamin Herrenschmidt
2008-03-06  0:44         ` Andrew Morton
2008-03-06  0:52           ` Benjamin Herrenschmidt
2008-03-04 18:36   ` Andrew Morton
2008-03-04 18:47     ` Pekka Enberg
2008-03-04 19:18     ` Pekka Enberg
2008-03-05  8:22   ` Benjamin Herrenschmidt
2008-03-04 16:35 ` 2.6.25-rc3-mm1 (IDE) Randy Dunlap
2008-03-06 21:14   ` Bartlomiej Zolnierkiewicz
2008-03-04 16:45 ` 2.6.25-rc3-mm1 (CCISS) Randy Dunlap
2008-03-04 17:02   ` Miller, Mike (OS Dev)
2008-03-04 17:14     ` Randy Dunlap
2008-03-04 18:14       ` Jens Axboe
2008-03-04 19:12 ` [PATCH 2.6.25-rc3-mm1] fix ext2 borkage Hugh Dickins
2008-03-04 19:20 ` [BUG] 2.6.25-rc3-mm1 kernel bug while running libhugetlbfs Kamalesh Babulal
2008-03-04 19:51   ` Andrew Morton
2008-03-04 22:01     ` Adam Litke
2008-03-05  7:52       ` Kamalesh Babulal
2008-03-04 20:24 ` 2.6.25-rc3-mm1 (wakeup) Randy Dunlap
2008-03-04 22:33   ` Rafael J. Wysocki
2008-03-05  7:40     ` Sam Ravnborg
2008-03-04 21:26 ` 2.6.25-rc3-mm1 (9p docs) Randy Dunlap
2008-03-04 21:43   ` Eric Van Hensbergen
2008-03-05  7:21 ` 2.6.25-rc3-mm1 - PROFILE_LIKELY redux Valdis.Kletnieks
2008-03-05 17:45   ` Andi Kleen
2008-03-05 18:02     ` Andrew Morton
2008-03-05 18:22       ` Andi Kleen
2008-03-05 22:26       ` Valdis.Kletnieks
2008-03-05 23:49         ` Andrew Morton [this message]
2008-03-05 19:59     ` Valdis.Kletnieks
2008-03-05 21:56       ` Andi Kleen
2008-03-05 10:51 ` prctl(0x8) -> EINVAL [Was: 2.6.25-rc3-mm1] Jiri Slaby
2008-03-05 10:59   ` Jiri Slaby
2008-03-05 14:06   ` Serge E. Hallyn
2008-03-05 15:18     ` Jiri Slaby
2008-03-09 16:28     ` Andrew Morgan
2008-03-05 13:04 ` 2.6.25-rc3-mm1 Pavel Emelyanov
2008-03-05 13:12   ` 2.6.25-rc3-mm1 (SYSFS=n breaks module engine) Pavel Emelyanov
2008-03-05 13:31   ` 2.6.25-rc3-mm1 Kay Sievers
2008-03-05 13:38     ` 2.6.25-rc3-mm1 Pavel Emelyanov
2008-03-05 13:54       ` 2.6.25-rc3-mm1 Kay Sievers
2008-03-05 14:28         ` 2.6.25-rc3-mm1 Pavel Emelyanov
2008-03-05 16:40   ` 2.6.25-rc3-mm1 Greg KH
2008-03-05 16:59     ` 2.6.25-rc3-mm1 Pavel Emelyanov
2008-03-05 17:07       ` 2.6.25-rc3-mm1 Greg KH
2008-03-05 21:34 ` 2.6.25-rc3-mm1 ppc64 boot hang Badari Pulavarty
2008-03-05 21:54   ` Andrew Morton
2008-03-05 22:35     ` Badari Pulavarty
2008-03-05 23:17     ` Stephen Rothwell
2008-03-07  3:58 ` 2.6.25-rc3-mm1 - BUG at system shutdown time Valdis.Kletnieks
2008-03-07  6:16   ` Andrew Morton
2008-03-07  7:52     ` Valdis.Kletnieks
2008-03-07  8:06       ` Thomas Gleixner
2008-03-07  8:23         ` Valdis.Kletnieks
2008-03-07  8:34           ` Thomas Gleixner
2008-03-07 19:30             ` Valdis.Kletnieks
2008-03-12  7:32   ` Andrew Morton
2008-03-13  2:19     ` Valdis.Kletnieks
2008-03-13  2:32       ` Andrew Morton
2008-03-13  3:57         ` Valdis.Kletnieks
2008-03-13  4:27           ` Andrew Morton
2008-03-14 18:50             ` Valdis.Kletnieks
2008-03-21 13:41       ` Ingo Molnar
2008-03-21 19:38         ` Valdis.Kletnieks
2008-03-21 19:58           ` Ingo Molnar
2008-03-21 20:05             ` Valdis.Kletnieks
2008-03-21 20:12               ` Ingo Molnar
2008-03-22  3:11                 ` Hoo-fscking-ray - (was " Valdis.Kletnieks
2008-03-22 12:09                   ` Ingo Molnar

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