realtime-preempt patch-2.6.15-rt18 issues

realtime-preempt patch-2.6.15-rt18 issues

[Rui Nuno Capela]

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Hi, Ingo,

I think I would let you know that I'm still on 2.6.15-rt16, which works
great for the most purposes, on all of my boxes.

My problem is that the current/latest of the realtime-preempt patch,
2.6.15-rt18, has some showstoppers, at least for my day-to-day usage.

First one, and I think this is a return of an old buglet. Its the one that
occurs every time an usb-storage device is unplugged (e.g. a usb flash
stick). Once that happens, the usb subsystem gets seriously crippled.

Here goes a sample dmesg output of this occurrence (the complete listing
is attached, as is the corresponding kernel .config).

...
usb 2-1: new full speed USB device using ohci_hcd and address 2
Initializing USB Mass Storage driver...
scsi0 : SCSI emulation for USB Mass Storage devices
usb-storage: device found at 2
usb-storage: waiting for device to settle before scanning
usbcore: registered new driver usb-storage
USB Mass Storage support registered.
  Vendor: USB 2.0   Model: Flash Disk        Rev: 2.00
  Type:   Direct-Access                      ANSI SCSI revision: 02
SCSI device sda: 2031616 512-byte hdwr sectors (1040 MB)
sda: Write Protect is off
sda: Mode Sense: 0b 00 00 08
sda: assuming drive cache: write through
SCSI device sda: 2031616 512-byte hdwr sectors (1040 MB)
sda: Write Protect is off
sda: Mode Sense: 0b 00 00 08
sda: assuming drive cache: write through
 sda: sda1
sd 0:0:0:0: Attached scsi removable disk sda
usb-storage: device scan complete
usb 2-1: USB disconnect, address 2
slab error in kmem_cache_destroy(): cache `scsi_cmd_cache': Can't free all
objects
 [<c0144603>] kmem_cache_destroy+0x83/0xf8 (8)
 [<c020b1d6>] scsi_destroy_command_freelist+0x4e/0x5a (12)
 [<c020be67>] scsi_host_dev_release+0x4e/0x71 (12)
 [<c01f0fef>] device_release+0x14/0x39 (12)
 [<c01a2c9b>] kobject_cleanup+0x3e/0x5e (4)
 [<c01a2cbb>] kobject_release+0x0/0x8 (8)
 [<e05327ac>] usb_stor_control_thread+0x0/0x183 [usb_storage] (8)
 [<c01a3432>] kref_put+0x3a/0x44 (4)
 [<e053290e>] usb_stor_control_thread+0x162/0x183 [usb_storage] (12)
 [<c027a8a1>] schedule+0xd4/0xf5 (32)
 [<c01230df>] kthread+0x63/0x8f (20)
 [<c012307c>] kthread+0x0/0x8f (12)
 [<c0100d59>] kernel_thread_helper+0x5/0xb (16)


The second issue seems to be related to the RTC and is not strictly
specific to -rt18. AFAICT, my experience goes far as the ALSA MIDI
sequencer is concerned (snd-seq-midi) and it badly shows whenever the RTC
timer is used (snd-rtctimer), moreover if its used by default (i.e.
CONFIG_SND_SEQ_RTCTIMER_DEFAULT=y).

As it seems specific to -rt18, the ALSA sequencer event queueing is
perfectly non-functional if the RTC timer is used. On -rt16, and probably
before, the use of snd-rtctimer is suspiciously related to some complete
and instantaneous system lockups that I was experiencing more than many
times, while doing some MIDI sequencing; it always occurred almost exactly
on queue timer stop/start instants. Once I got rid of the rtctimer,
everything seems to get back to normal, that is, no hard-freezes to date.

My current configurations tries to avoid the RTC use in any circunstance.

So I think RTC is still an open issue, and it has indeed surfaced here and
there, specially regarding the RT patch usage in the Linux Audio/MIDI
niche.

Hope I can help in anyway.

Cheers,
-- 
rncbc aka Rui Nuno Capela
rncbc@rncbc.org

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Re: realtime-preempt patch-2.6.15-rt18 issues

[Ingo Molnar]

* Rui Nuno Capela <rncbc@rncbc.org> wrote:

> Hi, Ingo,
> 
> I think I would let you know that I'm still on 2.6.15-rt16, which 
> works great for the most purposes, on all of my boxes.
> 
> My problem is that the current/latest of the realtime-preempt patch, 
> 2.6.15-rt18, has some showstoppers, at least for my day-to-day usage.

> The second issue seems to be related to the RTC and is not strictly 
> specific to -rt18. AFAICT, my experience goes far as the ALSA MIDI 
> sequencer is concerned (snd-seq-midi) and it badly shows whenever the 
> RTC timer is used (snd-rtctimer), moreover if its used by default 
> (i.e. CONFIG_SND_SEQ_RTCTIMER_DEFAULT=y).

does the patch below (from Karsten Wiese) solve the second problem?

	Ingo

-------

> the tasklet code was reworked too to be PREEMPT_RT friendly: the new 
> PI code unearthed a fundamental livelock scenario with PREEMPT_RT, and 
> the fix was to rework the tasklet code to get rid of the 'retrigger 
> softirqs' approach.

following patch re enables tasklet_hi. needed by ALSA MIDI.

      Karsten

--- linux/kernel/softirq.c.orig
+++ linux/kernel/softirq.c
@@ -351,13 +351,13 @@
 static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec) = { NULL };
 
 static void inline
-__tasklet_common_schedule(struct tasklet_struct *t, struct tasklet_head *head)
+__tasklet_common_schedule(struct tasklet_struct *t, struct tasklet_head *head, unsigned int nr)
 {
 	if (tasklet_trylock(t)) {
 		WARN_ON(t->next != NULL);
 		t->next = head->list;
 		head->list = t;
-		raise_softirq_irqoff(TASKLET_SOFTIRQ);
+		raise_softirq_irqoff(nr);
 		tasklet_unlock(t);
 	}
 }
@@ -367,7 +367,7 @@
 	unsigned long flags;
 
 	raw_local_irq_save(flags);
-	__tasklet_common_schedule(t, &__get_cpu_var(tasklet_vec));
+	__tasklet_common_schedule(t, &__get_cpu_var(tasklet_vec), TASKLET_SOFTIRQ);
 	raw_local_irq_restore(flags);
 }
 
@@ -378,7 +378,7 @@
 	unsigned long flags;
 
 	raw_local_irq_save(flags);
-	__tasklet_common_schedule(t, &__get_cpu_var(tasklet_hi_vec));
+	__tasklet_common_schedule(t, &__get_cpu_var(tasklet_hi_vec), HI_SOFTIRQ);
 	raw_local_irq_restore(flags);
 }
 

Re: realtime-preempt patch-2.6.15-rt18 issues

[Ingo Molnar]

* Rui Nuno Capela <rncbc@rncbc.org> wrote:

> Hi, Ingo,
> 
> I think I would let you know that I'm still on 2.6.15-rt16, which 
> works great for the most purposes, on all of my boxes.
> 
> My problem is that the current/latest of the realtime-preempt patch, 
> 2.6.15-rt18, has some showstoppers, at least for my day-to-day usage.
> 
> First one, and I think this is a return of an old buglet. Its the one 
> that occurs every time an usb-storage device is unplugged (e.g. a usb 
> flash stick). Once that happens, the usb subsystem gets seriously 
> crippled.
> 
> Here goes a sample dmesg output of this occurrence (the complete listing
> is attached, as is the corresponding kernel .config).
> 
> ...
> usb 2-1: USB disconnect, address 2
> slab error in kmem_cache_destroy(): cache `scsi_cmd_cache': Can't free all
> objects

hm, this implicates the SLAB code. I've uploaded -rt19, does it work any 
better [there i've included a newer version of the rt-SLAB code]? If you 
still get the same problem even under -rt19, do things improve if you 
enable CONFIG_EMBEDDED and CONFIG_SLOB?

(-rt19 also has the tasklet/ALSA fix, and some other fixlets)

	Ingo

Re: realtime-preempt patch-2.6.15-rt18 issues

[Rui Nuno Capela]

Ingo,

> Rui Nuno Capela wrote:
>
>>
>> ...
>> usb 2-1: USB disconnect, address 2 slab error in kmem_cache_destroy():
>> cache `scsi_cmd_cache': Can't free all objects
>
> hm, this implicates the SLAB code. I've uploaded -rt19, does it work any
> better [there i've included a newer version of the rt-SLAB code]? If you
> still get the same problem even under -rt19, do things improve if you
> enable CONFIG_EMBEDDED and CONFIG_SLOB?
>
> (-rt19 also has the tasklet/ALSA fix, and some other fixlets)
>

-rt19 doesn't compile here (either with CONFIG_EMBEDDED=y or not):

  ...
  CC      mm/slab.o
mm/slab.c:703: error: request for member 'lock' in something not a
structure or union
mm/slab.c:703: error: request for member 'lock' in something not a
structure or union
mm/slab.c:703: error: request for member 'lock' in something not a
structure or union
mm/slab.c:703: error: request for member 'lock' in something not a
structure or union
mm/slab.c:703: error: initializer element is not constant
mm/slab.c:703: error: (near initialization for 'cache_cache.spinlock')
make[1]: *** [mm/slab.o] Error 1
make: *** [mm] Error 2


Cheers.
-- 
rncbc aka Rui Nuno Capela
rncbc@rncbc.org

[PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues)

[Jan Altenberg]

Hi,

> -rt19 doesn't compile here (either with CONFIG_EMBEDDED=y or not):

same problem here. Looks like a typo...
Am I right?

Signed-off-by: Jan Altenberg <tb10alj@tglx.de>

--------------------------------------------------

--- slab.c.orig 2006-03-07 10:27:35.000000000 +0100
+++ slab.c      2006-03-07 10:28:17.000000000 +0100
@@ -700,7 +700,7 @@ static struct kmem_cache cache_cache = {
        .shared = 1,
        .buffer_size = sizeof(struct kmem_cache),
        .flags = SLAB_NO_REAP,
-       .spinlock = SPIN_LOCK_UNLOCKED(&cache_cache.spinlock),
+       .spinlock = SPIN_LOCK_UNLOCKED(cache_cache.spinlock),
        .name = "kmem_cache",
 #if DEBUG
        .obj_size = sizeof(struct kmem_cache),

Re: [PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues)

[Ingo Molnar]

* Jan Altenberg <tb10alj@tglx.de> wrote:

> Hi,
> 
> > -rt19 doesn't compile here (either with CONFIG_EMBEDDED=y or not):
> 
> same problem here. Looks like a typo...
> Am I right?

> -       .spinlock = SPIN_LOCK_UNLOCKED(&cache_cache.spinlock),
> +       .spinlock = SPIN_LOCK_UNLOCKED(cache_cache.spinlock),

indeed - i've uploaded -rt20 with this fix.

	Ingo

Re: [PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues)

[Rui Nuno Capela]

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On Tue, March 7, 2006 09:40, Jan Altenberg wrote:
> Hi,
>
>
>> -rt19 doesn't compile here (either with CONFIG_EMBEDDED=y or not):
>>
>
> same problem here. Looks like a typo... Am I right?
>

OK. Apllited to -rt19 and tested it all in a hurry.

- The ALSA sequencer RTC timer issue, which was completely broken on
-rt18, seems to be solved. However, its way too early to tell a thing
about the mentioned system lockups.

- The SLAB related usb-storage crash on disconnect is still there:

usb 2-1: new full speed USB device using ohci_hcd and address 2
Initializing USB Mass Storage driver...
scsi0 : SCSI emulation for USB Mass Storage devices
usb-storage: device found at 2
usb-storage: waiting for device to settle before scanning
usbcore: registered new driver usb-storage
USB Mass Storage support registered.
  Vendor: USB 2.0   Model: Flash Disk        Rev: 2.00
  Type:   Direct-Access                      ANSI SCSI revision: 02
SCSI device sda: 2031616 512-byte hdwr sectors (1040 MB)
sda: Write Protect is off
sda: Mode Sense: 0b 00 00 08
sda: assuming drive cache: write through
SCSI device sda: 2031616 512-byte hdwr sectors (1040 MB)
sda: Write Protect is off
sda: Mode Sense: 0b 00 00 08
sda: assuming drive cache: write through
 sda: sda1
sd 0:0:0:0: Attached scsi removable disk sda
usb-storage: device scan complete
usb 2-1: USB disconnect, address 2
slab error in kmem_cache_destroy(): cache `scsi_cmd_cache': Can't free all
objects
 [<c0141d1e>] kmem_cache_destroy+0x66/0xdb (8)
 [<c020487c>] scsi_destroy_command_freelist+0x4e/0x5a (12)
 [<c02054eb>] scsi_host_dev_release+0x4b/0x6e (12)
 [<c01eaca7>] device_release+0x14/0x39 (12)
 [<c019d07f>] kobject_cleanup+0x3e/0x5e (4)
 [<c019d09f>] kobject_release+0x0/0x8 (8)
 [<e054178c>] usb_stor_control_thread+0x0/0x183 [usb_storage] (8)
 [<c019d7ce>] kref_put+0x3a/0x44 (4)
 [<e05418ee>] usb_stor_control_thread+0x162/0x183 [usb_storage] (12)
 [<c0272dc9>] schedule+0xd4/0xf5 (32)
 [<c01226bf>] kthread+0x63/0x8f (20)
 [<c012265c>] kthread+0x0/0x8f (12)
 [<c0100d39>] kernel_thread_helper+0x5/0xb (16)


On reconnect, thereafter:

usb 2-1: new full speed USB device using ohci_hcd and address 3
kmem_cache_create: duplicate cache scsi_cmd_cache
 [<c0141aab>] kmem_cache_create+0x439/0x469 (8)
 [<c0157600>] __d_lookup+0xee/0xf8 (32)
 [<c02047bb>] scsi_setup_command_freelist+0x60/0xd3 (36)
 [<c020572f>] scsi_host_alloc+0x221/0x2ec (28)
 [<c01ebea5>] __device_attach+0x0/0x5 (16)
 [<e0541f44>] storage_probe+0x2b/0x1d0 [usb_storage] (4)
 [<c01ebea5>] __device_attach+0x0/0x5 (24)
 [<e002e071>] usb_probe_interface+0x4b/0x77 [usbcore] (4)
 [<c01ebe56>] driver_probe_device+0x32/0x81 (12)
 [<c01eb8cb>] bus_for_each_drv+0x36/0x58 (16)
 [<c01ebee6>] device_attach+0x3c/0x4b (32)
 [<c01ebea5>] __device_attach+0x0/0x5 (4)
 [<c01eb996>] bus_add_device+0x20/0x75 (12)
 [<c01eaf66>] device_add+0xd0/0x12e (20)
 [<e0034612>] usb_set_configuration+0x31d/0x377 [usbcore] (20)
 [<e002ffd2>] usb_new_device+0xef/0x148 [usbcore] (52)
 [<e0030d7f>] hub_port_connect_change+0x260/0x302 [usbcore] (20)
 [<e002ed50>] clear_port_feature+0x2b/0x30 [usbcore] (28)
 [<e00310aa>] hub_events+0x289/0x34d [usbcore] (28)
 [<c0272dc9>] schedule+0xd4/0xf5 (24)
 [<e003116e>] hub_thread+0x0/0xcb [usbcore] (16)
 [<e0031177>] hub_thread+0x9/0xcb [usbcore] (4)
 [<c0122a57>] autoremove_wake_function+0x0/0x2d (12)
 [<c01226bf>] kthread+0x63/0x8f (16)
 [<c012265c>] kthread+0x0/0x8f (12)
 [<c0100d39>] kernel_thread_helper+0x5/0xb (16)
 [<c014ae4a>] lookup_bdev+0x1f/0x71 (20)
usb-storage: Unable to allocate the scsi host
usb-storage: probe of 2-1:1.0 failed with error -12


Complete dmesg and .config on attach, as usual.

Cheers.
-- 
rncbc aka Rui Nuno Capela
rncbc@rncbc.org

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Re: [PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues)

[Rui Nuno Capela]

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Hi,

Still got the blues whenever I try to unplug a usb-storage stick on -rt20 ;)

usb 2-1: new full speed USB device using ohci_hcd and address 2
Initializing USB Mass Storage driver...
scsi0 : SCSI emulation for USB Mass Storage devices
usb-storage: device found at 2
usb-storage: waiting for device to settle before scanning
usbcore: registered new driver usb-storage
USB Mass Storage support registered.
  Vendor: USB 2.0   Model: Flash Disk        Rev: 2.00
  Type:   Direct-Access                      ANSI SCSI revision: 02
SCSI device sda: 2031616 512-byte hdwr sectors (1040 MB)
sda: Write Protect is off
sda: Mode Sense: 0b 00 00 08
sda: assuming drive cache: write through
SCSI device sda: 2031616 512-byte hdwr sectors (1040 MB)
sda: Write Protect is off
sda: Mode Sense: 0b 00 00 08
sda: assuming drive cache: write through
 sda: sda1
sd 0:0:0:0: Attached scsi removable disk sda
usb-storage: device scan complete
usb 2-1: USB disconnect, address 2
slab error in kmem_cache_destroy(): cache `scsi_cmd_cache': Can't free all
objects
 [<c0141d1e>] kmem_cache_destroy+0x66/0xdb (8)
 [<c020487c>] scsi_destroy_command_freelist+0x4e/0x5a (12)
 [<c02054eb>] scsi_host_dev_release+0x4b/0x6e (12)
 [<c01eaca7>] device_release+0x14/0x39 (12)
 [<c019d07f>] kobject_cleanup+0x3e/0x5e (4)
 [<c019d09f>] kobject_release+0x0/0x8 (8)
 [<e053278c>] usb_stor_control_thread+0x0/0x183 [usb_storage] (8)
 [<c019d7ce>] kref_put+0x3a/0x44 (4)
 [<e05328ee>] usb_stor_control_thread+0x162/0x183 [usb_storage] (12)
 [<c0272dc1>] schedule+0xd4/0xf5 (32)
 [<c01226bf>] kthread+0x63/0x8f (20)
 [<c012265c>] kthread+0x0/0x8f (12)
 [<c0100d39>] kernel_thread_helper+0x5/0xb (16)

BR
-- 
rncbc aka Rui Nuno Capela
rncbc@rncbc.org

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Re: realtime-preempt patch-2.6.15-rt18 issues

[Jan Altenberg]

Hi,

> - The SLAB related usb-storage crash on disconnect is still there:

I'm facing the same problem with -rt21. Kernel config, lspci -vvx
and dmesg output can be downloaded from:
http://www.tglx.de/private/tb10alj/rt21/

Unplugging the USB device causes:

 slab error in kmem_cache_destroy(): cache `scsi_cmd_cache': Can't free all objects
  [<c0161576>] kmem_cache_destroy+0xe9/0x11c (8)
  [<c037eac7>] scsi_destroy_command_freelist+0x4b/0x79 (24)
  [<c037fa47>] scsi_host_dev_release+0x46/0x8c (24)
  [<c031559c>] device_release+0x1c/0x51 (16)
  [<c02814b7>] kobject_cleanup+0x98/0x9a (16)
  [<c02814b9>] kobject_release+0x0/0xa (12)
  [<c03cf161>] usb_stor_control_thread+0x0/0x1a8 (8)
  [<c0281e91>] kref_put+0x3d/0x80 (4)
  [<c02814e1>] kobject_put+0x1e/0x22 (24)
  [<c02814b9>] kobject_release+0x0/0xa (8)
  [<c03cf2f5>] usb_stor_control_thread+0x194/0x1a8 (4)
  [<c04a1091>] schedule+0x47/0x134 (36)
  [<c011cfeb>] complete+0x4c/0x75 (4)
  [<c0134bfd>] kthread+0xb1/0xb7 (36)
  [<c0134b4c>] kthread+0x0/0xb7 (32)
  [<c01013ed>] kernel_thread_helper+0x5/0xb (16)

After reconnecting:

 kmem_cache_create: duplicate cache scsi_cmd_cache
  [<c016112d>] kmem_cache_create+0x638/0x6ae (8)
  [<c01398f1>] _spin_lock_init+0x2f/0x33 (52)
  [<c037e9fd>] scsi_setup_command_freelist+0x8d/0x10c (24)
  [<c013965a>] __init_MUTEX+0x20/0x28 (40)
  [<c037fcc0>] scsi_host_alloc+0x233/0x360 (16)
  [<c03cfa82>] storage_probe+0x36/0x221 (52)
  [<c03b0bf0>] usb_probe_interface+0x7d/0xa8 (52)
  [<c0317251>] driver_probe_device+0x69/0xd0 (24)
  [<c03172b8>] __device_attach+0x0/0x5 (28)
  [<c0316921>] bus_for_each_drv+0x65/0x7b (8)
  [<c0317327>] device_attach+0x6a/0x6e (48)
  [<c03172b8>] __device_attach+0x0/0x5 (16)
  [<c0316a62>] bus_add_device+0x51/0xcc (12)
  [<c03159bb>] device_add+0x122/0x198 (32)
  [<c03b903f>] usb_set_configuration+0x2c3/0x430 (36)
  [<c03b3585>] usb_new_device+0xe4/0x19d (80)
  [<c03b46e2>] hub_port_connect_change+0x214/0x3df (40)
  [<c03b000a>] cdrom_get_last_written+0xca/0x136 (28)
  [<c03b4b72>] hub_events+0x2c5/0x427 (40)
  [<c03b4ceb>] hub_thread+0x17/0xea (52)
  [<c01350c1>] autoremove_wake_function+0x0/0x57 (12)
  [<c01350c1>] autoremove_wake_function+0x0/0x57 (32)
  [<c04a11dc>] preempt_schedule+0x5e/0x84 (20)
  [<c03b4cd4>] hub_thread+0x0/0xea (16)
  [<c0134bfd>] kthread+0xb1/0xb7 (4)
  [<c0134b4c>] kthread+0x0/0xb7 (32)
  [<c01013ed>] kernel_thread_helper+0x5/0xb (16)


Cheers,
JAN

Re: [PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues)

[karsten wiese]

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--- Rui Nuno Capela <rncbc@rncbc.org> schrieb:
> - The SLAB related usb-storage crash on disconnect is
> still there:

and its still in up to rc6-rt3, unless you apply attached
patch. My uniprocessor behaves with it.

Ingo, what exactly needs fixing here?

cheers,
Karsten


	

	
		
___________________________________________________________ 
Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de

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--- ./mm/slab.c~	2006-03-15 00:15:49.000000000 +0100
+++ ./mm/slab.c	2006-03-15 00:15:49.000000000 +0100
@@ -2169,7 +2169,7 @@
 	int node;
 
 // FIXME:
-//	smp_call_function_all_cpus(do_drain, cachep);
+	smp_call_function_all_cpus(do_drain, cachep);
 	check_irq_on();
 	for_each_online_node(node) {
 		l3 = cachep->nodelists[node];

Re: [PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues)

[Ingo Molnar]

* karsten wiese <annabellesgarden@yahoo.de> wrote:

> 
> --- Rui Nuno Capela <rncbc@rncbc.org> schrieb:
> > - The SLAB related usb-storage crash on disconnect is
> > still there:
> 
> and its still in up to rc6-rt3, unless you apply attached patch. My 
> uniprocessor behaves with it.

ah, indeed!

> Ingo, what exactly needs fixing here?

smp_call_function() will call things in a hardirq context, so calling 
do_drain() from there [which uses preemptible spinlocks, etc.] is 
unsafe. (it will work most of the time, but not all of the time) It 
should rather be done from some per-CPU task.

a better fix would be the one below - it still does the call on the 
current CPU, and skips other CPUs (on SMP). Does this solve the problem 
on your box too?

	Ingo

Index: linux-rt.q/mm/slab.c
===================================================================
--- linux-rt.q.orig/mm/slab.c
+++ linux-rt.q/mm/slab.c
@@ -2192,19 +2192,20 @@ static void check_spinlock_acquired_node
  */
 static void smp_call_function_all_cpus(void (*func)(void *arg), void *arg)
 {
-	unsigned long flags;
+	unsigned int this_cpu;
 
 	check_irq_on();
-	preempt_disable();
+//	preempt_disable();
 
-	slab_irq_disable(flags);
+	slab_irq_disable(this_cpu);
 	func(arg);
-	slab_irq_enable(flags);
+	slab_irq_enable(this_cpu);
 
-	if (smp_call_function(func, arg, 1, 1))
-		BUG();
+// FIXME
+//	if (smp_call_function(func, arg, 1, 1))
+//		BUG();
 
-	preempt_enable();
+//	preempt_enable();
 }
 
 static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac,
@@ -2231,8 +2232,7 @@ static void drain_cpu_caches(struct kmem
 	int this_cpu;
 	int node;
 
-// FIXME:
-//	smp_call_function_all_cpus(do_drain, cachep);
+	smp_call_function_all_cpus(do_drain, cachep);
 	check_irq_on();
 	for_each_online_node(node) {
 		l3 = cachep->nodelists[node];

Re: [PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues)

[Jan Altenberg]

Hi,

> a better fix would be the one below - it still does the call on the 
> current CPU, and skips other CPUs (on SMP). Does this solve the problem 
> on your box too?

Tested in all a hurry and it seems to work for me too.

Cheers,
JAN

Re: [PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues)

[Ingo Molnar]

* Jan Altenberg <tb10alj@tglx.de> wrote:

> > a better fix would be the one below - it still does the call on the 
> > current CPU, and skips other CPUs (on SMP). Does this solve the problem 
> > on your box too?
> 
> Tested in all a hurry and it seems to work for me too.

a full fix is below: this re-enables the full SLAB related smp-call 
functionality on PREEMPT_RT too (without any hackery), and fixes a 
couple of rt-NUMA bugs as well.

	Ingo

Index: linux-rt.q/mm/slab.c
===================================================================
--- linux-rt.q.orig/mm/slab.c
+++ linux-rt.q/mm/slab.c
@@ -147,9 +147,9 @@
 # define slab_spin_unlock_irqrestore(lock, flags, cpu) \
  	do { spin_unlock_irqrestore(lock, flags); } while (0)
 #else
-DEFINE_PER_CPU_LOCKED(int, slab_locks) = { 0, };
-# define slab_irq_disable(cpu)		get_cpu_var_locked(slab_locks, &(cpu))
-# define slab_irq_enable(cpu)		put_cpu_var_locked(slab_locks, cpu)
+DEFINE_PER_CPU_LOCKED(int, slab_irq_locks) = { 0, };
+# define slab_irq_disable(cpu)		get_cpu_var_locked(slab_irq_locks, &(cpu))
+# define slab_irq_enable(cpu)		put_cpu_var_locked(slab_irq_locks, cpu)
 # define slab_irq_save(flags, cpu) \
 	do { slab_irq_disable(cpu); (void) (flags); } while (0)
 # define slab_irq_restore(flags, cpu) \
@@ -989,7 +989,8 @@ static void __drain_alien_cache(struct k
 /*
  * Called from cache_reap() to regularly drain alien caches round robin.
  */
-static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
+static void
+reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3, int *this_cpu)
 {
 	int node = __get_cpu_var(reap_node);
 
@@ -997,7 +998,7 @@ static void reap_alien(struct kmem_cache
 		struct array_cache *ac = l3->alien[node];
 		if (ac && ac->avail) {
 			spin_lock_irq(&ac->lock);
-			__drain_alien_cache(cachep, ac, node);
+			__drain_alien_cache(cachep, ac, node, this_cpu);
 			spin_unlock_irq(&ac->lock);
 		}
 	}
@@ -1022,7 +1023,7 @@ static void drain_alien_cache(struct kme
 #else
 
 #define drain_alien_cache(cachep, alien) do { } while (0)
-#define reap_alien(cachep, l3) do { } while (0)
+#define reap_alien(cachep, l3, this_cpu) do { } while (0)
 
 static inline struct array_cache **alloc_alien_cache(int node, int limit)
 {
@@ -2164,14 +2165,6 @@ static void check_irq_on(void)
 #endif
 }
 
-static void check_spinlock_acquired(struct kmem_cache *cachep)
-{
-#ifdef CONFIG_SMP
-	check_irq_off();
-	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
-#endif
-}
-
 static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
 {
 #ifdef CONFIG_SMP
@@ -2183,39 +2176,57 @@ static void check_spinlock_acquired_node
 #else
 #define check_irq_off()	do { } while(0)
 #define check_irq_on()	do { } while(0)
-#define check_spinlock_acquired(x) do { } while(0)
 #define check_spinlock_acquired_node(x, y) do { } while(0)
 #endif
 
+#ifdef CONFIG_PREEMPT_RT
+/*
+ * execute func() for all CPUs. On PREEMPT_RT we dont actually have
+ * to run on the remote CPUs - we only have to take their CPU-locks.
+ * (This is a rare operation, so cacheline bouncing is not an issue.)
+ */
+static void
+smp_call_function_all_cpus(void (*func)(void *arg, int this_cpu), void *arg)
+{
+	unsigned int i;
+
+	check_irq_on();
+	for_each_online_cpu(i) {
+		spin_lock(&__get_cpu_lock(slab_irq_locks, i));
+		func(arg, i);
+		spin_unlock(&__get_cpu_lock(slab_irq_locks, i));
+	}
+}
+#else
 /*
  * Waits for all CPUs to execute func().
  */
 static void smp_call_function_all_cpus(void (*func)(void *arg), void *arg)
 {
-	unsigned long flags;
+	unsigned int this_cpu;
 
 	check_irq_on();
 	preempt_disable();
 
-	slab_irq_disable(flags);
+	slab_irq_disable(this_cpu);
 	func(arg);
-	slab_irq_enable(flags);
+	slab_irq_enable(this_cpu);
 
 	if (smp_call_function(func, arg, 1, 1))
 		BUG();
 
 	preempt_enable();
 }
+#endif
 
 static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac,
 				int force, int node);
 
-static void do_drain(void *arg)
+static void __do_drain(void *arg, int this_cpu)
 {
 	struct kmem_cache *cachep = (struct kmem_cache *) arg;
+	int node = cpu_to_node(this_cpu);
 	struct array_cache *ac;
-	int node = numa_node_id();
-	int this_cpu = smp_processor_id();
 
 	check_irq_off();
 	ac = cpu_cache_get(cachep, this_cpu);
@@ -2225,14 +2236,25 @@ static void do_drain(void *arg)
 	ac->avail = 0;
 }
 
+#ifdef CONFIG_PREEMPT_RT
+static void do_drain(void *arg, int this_cpu)
+{
+	__do_drain(arg, this_cpu);
+}
+#else
+static void do_drain(void *arg)
+{
+	__do_drain(arg, smp_processor_id());
+}
+#endif
+
 static void drain_cpu_caches(struct kmem_cache *cachep)
 {
 	struct kmem_list3 *l3;
 	int this_cpu;
 	int node;
 
-// FIXME:
-//	smp_call_function_all_cpus(do_drain, cachep);
+	smp_call_function_all_cpus(do_drain, cachep);
 	check_irq_on();
 	for_each_online_node(node) {
 		l3 = cachep->nodelists[node];
@@ -2759,7 +2781,7 @@ cache_alloc_refill(struct kmem_cache *ca
 		 */
 		batchcount = BATCHREFILL_LIMIT;
 	}
-	l3 = cachep->nodelists[numa_node_id()];
+	l3 = cachep->nodelists[cpu_to_node(*this_cpu)];
 
 	BUG_ON(ac->avail > 0 || !l3);
 	spin_lock(&l3->list_lock);
@@ -2792,14 +2814,14 @@ cache_alloc_refill(struct kmem_cache *ca
 
 		slabp = list_entry(entry, struct slab, list);
 		check_slabp(cachep, slabp);
-		check_spinlock_acquired(cachep);
+		check_spinlock_acquired_node(cachep, cpu_to_node(*this_cpu));
 		while (slabp->inuse < cachep->num && batchcount--) {
 			STATS_INC_ALLOCED(cachep);
 			STATS_INC_ACTIVE(cachep);
 			STATS_SET_HIGH(cachep);
 
 			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
-							    numa_node_id());
+						    cpu_to_node(*this_cpu));
 		}
 		check_slabp(cachep, slabp);
 
@@ -2818,7 +2840,7 @@ cache_alloc_refill(struct kmem_cache *ca
 
 	if (unlikely(!ac->avail)) {
 		int x;
-		x = cache_grow(cachep, flags, numa_node_id(), this_cpu);
+		x = cache_grow(cachep, flags, cpu_to_node(*this_cpu), this_cpu);
 
 		// cache_grow can reenable interrupts, then ac could change.
 		ac = cpu_cache_get(cachep, *this_cpu);
@@ -2901,7 +2923,7 @@ ____cache_alloc(struct kmem_cache *cache
 	if (unlikely(current->mempolicy && !in_interrupt())) {
 		int nid = slab_node(current->mempolicy);
 
-		if (nid != numa_node_id())
+		if (nid != cpu_to_node(*this_cpu))
 			return __cache_alloc_node(cachep, flags, nid, this_cpu);
 	}
 #endif
@@ -3043,11 +3065,12 @@ static void free_block(struct kmem_cache
 	}
 }
 
-static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac, int *this_cpu)
+static void
+cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac, int *this_cpu)
 {
 	int batchcount;
 	struct kmem_list3 *l3;
-	int node = numa_node_id();
+	int node = cpu_to_node(*this_cpu);
 
 	batchcount = ac->batchcount;
 #if DEBUG
@@ -3117,11 +3140,11 @@ __cache_free(struct kmem_cache *cachep, 
 	{
 		struct slab *slabp;
 		slabp = virt_to_slab(objp);
-		if (unlikely(slabp->nodeid != numa_node_id())) {
+		if (unlikely(slabp->nodeid != cpu_to_node(*this_cpu))) {
 			struct array_cache *alien = NULL;
 			int nodeid = slabp->nodeid;
 			struct kmem_list3 *l3 =
-			    cachep->nodelists[numa_node_id()];
+			    cachep->nodelists[cpu_to_node(*this_cpu)];
 
 			STATS_INC_NODEFREES(cachep);
 			if (l3->alien && l3->alien[nodeid]) {
@@ -3231,7 +3254,7 @@ void *kmem_cache_alloc_node(struct kmem_
 
 	cache_alloc_debugcheck_before(cachep, flags);
 	slab_irq_save(save_flags, this_cpu);
-	if (nodeid == -1 || nodeid == numa_node_id() ||
+	if (nodeid == -1 || nodeid == cpu_to_node(this_cpu) ||
 	    !cachep->nodelists[nodeid])
 		ptr = ____cache_alloc(cachep, flags, &this_cpu);
 	else
@@ -3508,18 +3531,31 @@ struct ccupdate_struct {
 	struct array_cache *new[NR_CPUS];
 };
 
-static void do_ccupdate_local(void *info)
+static void __do_ccupdate_local(void *info, int this_cpu)
 {
 	struct ccupdate_struct *new = (struct ccupdate_struct *)info;
 	struct array_cache *old;
 
 	check_irq_off();
-	old = cpu_cache_get(new->cachep, smp_processor_id());
+	old = cpu_cache_get(new->cachep, this_cpu);
 
-	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
-	new->new[smp_processor_id()] = old;
+	new->cachep->array[this_cpu] = new->new[this_cpu];
+	new->new[this_cpu] = old;
 }
 
+#ifdef CONFIG_PREEMPT_RT
+static void do_ccupdate_local(void *arg, int this_cpu)
+{
+	__do_ccupdate_local(arg, this_cpu);
+}
+#else
+static void do_ccupdate_local(void *info)
+{
+	__do_ccupdate_local(arg, smp_processor_id());
+}
+#endif
+
+
 static int do_tune_cpucache(struct kmem_cache *cachep, int limit, int batchcount,
 			    int shared)
 {
@@ -3654,9 +3690,9 @@ static void drain_array_locked(struct km
  */
 static void cache_reap(void *unused)
 {
+	int this_cpu = raw_smp_processor_id();
 	struct list_head *walk;
 	struct kmem_list3 *l3;
-	int this_cpu;
 
 	if (!mutex_trylock(&cache_chain_mutex)) {
 		/* Give up. Setup the next iteration. */
@@ -3678,12 +3714,13 @@ static void cache_reap(void *unused)
 
 		check_irq_on();
 
-		l3 = searchp->nodelists[numa_node_id()];
-		reap_alien(searchp, l3);
+		l3 = searchp->nodelists[cpu_to_node(this_cpu)];
+		reap_alien(searchp, l3, &this_cpu);
+
 		slab_spin_lock_irq(&l3->list_lock, this_cpu);
 
 		drain_array_locked(searchp, cpu_cache_get(searchp, this_cpu), 0,
-				   numa_node_id());
+				   cpu_to_node(this_cpu));
 
 		if (time_after(l3->next_reap, jiffies))
 			goto next_unlock;
@@ -3692,7 +3729,7 @@ static void cache_reap(void *unused)
 
 		if (l3->shared)
 			drain_array_locked(searchp, l3->shared, 0,
-					   numa_node_id());
+					   cpu_to_node(this_cpu));
 
 		if (l3->free_touched) {
 			l3->free_touched = 0;

Re: [PATCH] realtime-preempt patch-2.6.15-rt19 compile error (was: realtime-preempt patch-2.6.15-rt18 issues)

[karsten wiese]

[-- Attachment #1: Type: text/plain, Size: 790 bytes --]


--- Ingo Molnar <mingo@elte.hu> schrieb:

> 
> * Jan Altenberg <tb10alj@tglx.de> wrote:
> 
> > > a better fix would be the one below - it still does
> the call on the 
> > > current CPU, and skips other CPUs (on SMP). Does this
> solve the problem 
> > > on your box too?
> > 
> > Tested in all a hurry and it seems to work for me too.
> 
> a full fix is below: this re-enables the full SLAB
> related smp-call 
> functionality on PREEMPT_RT too (without any hackery),
> and fixes a 
> couple of rt-NUMA bugs as well.
> 
Hand applied your full fix against 2.6.15-rt21 (local diff
attached).
Works fine here on uniprocessor, Thanks!

      Karsten


	

	
		
___________________________________________________________ 
Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 3654053042-slab_fix.diff --]
[-- Type: text/x-diff; name="slab_fix.diff", Size: 8476 bytes --]

--- linux-2.6.15/rt21/mm/slab_0.c	2006-03-15 15:04:01.000000000 +0100
+++ linux-2.6.15/rt21/mm/slab.c	2006-03-15 15:04:01.000000000 +0100
@@ -147,9 +147,9 @@
 # define slab_spin_unlock_irqrestore(lock, flags, cpu) \
  	do { spin_unlock_irqrestore(lock, flags); } while (0)
 #else
-DEFINE_PER_CPU_LOCKED(int, slab_locks) = { 0, };
-# define slab_irq_disable(cpu)		get_cpu_var_locked(slab_locks, &(cpu))
-# define slab_irq_enable(cpu)		put_cpu_var_locked(slab_locks, cpu)
+DEFINE_PER_CPU_LOCKED(int, slab_irq_locks) = { 0, };
+# define slab_irq_disable(cpu)		get_cpu_var_locked(slab_irq_locks, &(cpu))
+# define slab_irq_enable(cpu)		put_cpu_var_locked(slab_irq_locks, cpu)
 # define slab_irq_save(flags, cpu) \
 	do { slab_irq_disable(cpu); (void) (flags); } while (0)
 # define slab_irq_restore(flags, cpu) \
@@ -944,6 +944,24 @@
 	}
 }
 
+/*
+ * Called from cache_reap() to regularly drain alien caches round robin.
+ */
+static void
+reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3, int *this_cpu)
+{
+	int node = __get_cpu_var(reap_node);
+
+	if (l3->alien) {
+		struct array_cache *ac = l3->alien[node];
+		if (ac && ac->avail) {
+			spin_lock_irq(&ac->lock);
+			__drain_alien_cache(cachep, ac, node, this_cpu);
+			spin_unlock_irq(&ac->lock);
+		}
+	}
+}
+
 static void drain_alien_cache(struct kmem_cache *cachep, struct array_cache **alien)
 {
 	int i = 0;
@@ -963,6 +981,7 @@
 #else
 
 #define drain_alien_cache(cachep, alien) do { } while (0)
+#define reap_alien(cachep, l3, this_cpu) do { } while (0)
 
 static inline struct array_cache **alloc_alien_cache(int node, int limit)
 {
@@ -2101,14 +2120,6 @@
 #endif
 }
 
-static void check_spinlock_acquired(struct kmem_cache *cachep)
-{
-#ifdef CONFIG_SMP
-	check_irq_off();
-	assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
-#endif
-}
-
 static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
 {
 #ifdef CONFIG_SMP
@@ -2120,39 +2131,57 @@
 #else
 #define check_irq_off()	do { } while(0)
 #define check_irq_on()	do { } while(0)
-#define check_spinlock_acquired(x) do { } while(0)
 #define check_spinlock_acquired_node(x, y) do { } while(0)
 #endif
 
+#ifdef CONFIG_PREEMPT_RT
+/*
+ * execute func() for all CPUs. On PREEMPT_RT we dont actually have
+ * to run on the remote CPUs - we only have to take their CPU-locks.
+ * (This is a rare operation, so cacheline bouncing is not an issue.)
+ */
+static void
+smp_call_function_all_cpus(void (*func)(void *arg, int this_cpu), void *arg)
+{
+	unsigned int i;
+
+	check_irq_on();
+	for_each_online_cpu(i) {
+		spin_lock(&__get_cpu_lock(slab_irq_locks, i));
+		func(arg, i);
+		spin_unlock(&__get_cpu_lock(slab_irq_locks, i));
+	}
+}
+#else
 /*
  * Waits for all CPUs to execute func().
  */
 static void smp_call_function_all_cpus(void (*func)(void *arg), void *arg)
 {
-	unsigned long flags;
+	unsigned int this_cpu;
 
 	check_irq_on();
 	preempt_disable();
 
-	slab_irq_disable(flags);
+	slab_irq_disable(this_cpu);
 	func(arg);
-	slab_irq_enable(flags);
+	slab_irq_enable(this_cpu);
 
 	if (smp_call_function(func, arg, 1, 1))
 		BUG();
 
 	preempt_enable();
 }
+#endif
 
 static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac,
 				int force, int node);
 
-static void do_drain(void *arg)
+static void __do_drain(void *arg, int this_cpu)
 {
 	struct kmem_cache *cachep = (struct kmem_cache *) arg;
+	int node = cpu_to_node(this_cpu);
 	struct array_cache *ac;
-	int node = numa_node_id();
-	int this_cpu = smp_processor_id();
 
 	check_irq_off();
 	ac = cpu_cache_get(cachep, this_cpu);
@@ -2162,14 +2191,25 @@
 	ac->avail = 0;
 }
 
+#ifdef CONFIG_PREEMPT_RT
+static void do_drain(void *arg, int this_cpu)
+{
+	__do_drain(arg, this_cpu);
+}
+#else
+static void do_drain(void *arg)
+{
+	__do_drain(arg, smp_processor_id());
+}
+#endif
+
 static void drain_cpu_caches(struct kmem_cache *cachep)
 {
 	struct kmem_list3 *l3;
 	int this_cpu;
 	int node;
 
-// FIXME:
-//	smp_call_function_all_cpus(do_drain, cachep);
+	smp_call_function_all_cpus(do_drain, cachep);
 	check_irq_on();
 	for_each_online_node(node) {
 		l3 = cachep->nodelists[node];
@@ -2696,7 +2736,7 @@
 		 */
 		batchcount = BATCHREFILL_LIMIT;
 	}
-	l3 = cachep->nodelists[numa_node_id()];
+	l3 = cachep->nodelists[cpu_to_node(*this_cpu)];
 
 	BUG_ON(ac->avail > 0 || !l3);
 	spin_lock(&l3->list_lock);
@@ -2729,14 +2769,14 @@
 
 		slabp = list_entry(entry, struct slab, list);
 		check_slabp(cachep, slabp);
-		check_spinlock_acquired(cachep);
+		check_spinlock_acquired_node(cachep, cpu_to_node(*this_cpu));
 		while (slabp->inuse < cachep->num && batchcount--) {
 			STATS_INC_ALLOCED(cachep);
 			STATS_INC_ACTIVE(cachep);
 			STATS_SET_HIGH(cachep);
 
 			ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
-							    numa_node_id());
+						    cpu_to_node(*this_cpu));
 		}
 		check_slabp(cachep, slabp);
 
@@ -2755,7 +2795,7 @@
 
 	if (unlikely(!ac->avail)) {
 		int x;
-		x = cache_grow(cachep, flags, numa_node_id(), this_cpu);
+		x = cache_grow(cachep, flags, cpu_to_node(*this_cpu), this_cpu);
 
 		// cache_grow can reenable interrupts, then ac could change.
 		ac = cpu_cache_get(cachep, *this_cpu);
@@ -2838,7 +2878,7 @@
 	if (unlikely(current->mempolicy && !in_interrupt())) {
 		int nid = slab_node(current->mempolicy);
 
-		if (nid != numa_node_id())
+		if (nid != cpu_to_node(*this_cpu))
 			return __cache_alloc_node(cachep, flags, nid, this_cpu);
 	}
 #endif
@@ -2980,11 +3020,12 @@
 	}
 }
 
-static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac, int *this_cpu)
+static void
+cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac, int *this_cpu)
 {
 	int batchcount;
 	struct kmem_list3 *l3;
-	int node = numa_node_id();
+	int node = cpu_to_node(*this_cpu);
 
 	batchcount = ac->batchcount;
 #if DEBUG
@@ -3054,11 +3095,11 @@
 	{
 		struct slab *slabp;
 		slabp = virt_to_slab(objp);
-		if (unlikely(slabp->nodeid != numa_node_id())) {
+		if (unlikely(slabp->nodeid != cpu_to_node(*this_cpu))) {
 			struct array_cache *alien = NULL;
 			int nodeid = slabp->nodeid;
 			struct kmem_list3 *l3 =
-			    cachep->nodelists[numa_node_id()];
+			    cachep->nodelists[cpu_to_node(*this_cpu)];
 
 			STATS_INC_NODEFREES(cachep);
 			if (l3->alien && l3->alien[nodeid]) {
@@ -3168,7 +3209,7 @@
 
 	cache_alloc_debugcheck_before(cachep, flags);
 	slab_irq_save(save_flags, this_cpu);
-	if (nodeid == -1 || nodeid == numa_node_id() ||
+	if (nodeid == -1 || nodeid == cpu_to_node(this_cpu) ||
 	    !cachep->nodelists[nodeid])
 		ptr = ____cache_alloc(cachep, flags, &this_cpu);
 	else
@@ -3444,18 +3485,31 @@
 	struct array_cache *new[NR_CPUS];
 };
 
-static void do_ccupdate_local(void *info)
+static void __do_ccupdate_local(void *info, int this_cpu)
 {
 	struct ccupdate_struct *new = (struct ccupdate_struct *)info;
 	struct array_cache *old;
 
 	check_irq_off();
-	old = cpu_cache_get(new->cachep, smp_processor_id());
+	old = cpu_cache_get(new->cachep, this_cpu);
 
-	new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
-	new->new[smp_processor_id()] = old;
+	new->cachep->array[this_cpu] = new->new[this_cpu];
+	new->new[this_cpu] = old;
 }
 
+#ifdef CONFIG_PREEMPT_RT
+static void do_ccupdate_local(void *arg, int this_cpu)
+{
+	__do_ccupdate_local(arg, this_cpu);
+}
+#else
+static void do_ccupdate_local(void *info)
+{
+	__do_ccupdate_local(arg, smp_processor_id());
+}
+#endif
+
+
 static int do_tune_cpucache(struct kmem_cache *cachep, int limit, int batchcount,
 			    int shared)
 {
@@ -3590,9 +3644,9 @@
  */
 static void cache_reap(void *unused)
 {
+	int this_cpu = raw_smp_processor_id();
 	struct list_head *walk;
 	struct kmem_list3 *l3;
-	int this_cpu;
 
 	if (down_trylock(&cache_chain_sem)) {
 		/* Give up. Setup the next iteration. */
@@ -3614,13 +3668,13 @@
 
 		check_irq_on();
 
-		l3 = searchp->nodelists[numa_node_id()];
-		if (l3->alien)
-			drain_alien_cache(searchp, l3->alien);
+		l3 = searchp->nodelists[cpu_to_node(this_cpu)];
+		reap_alien(searchp, l3, &this_cpu);
+
 		slab_spin_lock_irq(&l3->list_lock, this_cpu);
 
 		drain_array_locked(searchp, cpu_cache_get(searchp, this_cpu), 0,
-				   numa_node_id());
+				   cpu_to_node(this_cpu));
 
 		if (time_after(l3->next_reap, jiffies))
 			goto next_unlock;
@@ -3629,7 +3683,7 @@
 
 		if (l3->shared)
 			drain_array_locked(searchp, l3->shared, 0,
-					   numa_node_id());
+					   cpu_to_node(this_cpu));
 
 		if (l3->free_touched) {
 			l3->free_touched = 0;