linux_dsm_epyc7002/drivers
John Kacur 804a5cb526 [SCSI] hpsa: fix warning with smp_processor_id() in preemptible
section Signed-off-by: John Kacur <jkacur@redhat.com>

On a 3.6-rt (real-time patch) kernel we are seeing the following BUG
However, it appears to be relevant for non-realtime (mainline) as well.

[   49.688847] hpsa 0000:03:00.0: hpsa0: <0x323a> at IRQ 67 using DAC
[   49.749928] scsi0 : hpsa
[   49.784437] BUG: using smp_processor_id() in preemptible [00000000
00000000] code: kworker/u:0/6
[   49.784465] caller is enqueue_cmd_and_start_io+0x5a/0x100 [hpsa]
[   49.784468] Pid: 6, comm: kworker/u:0 Not tainted
3.6.11.5-rt37.52.el6rt.x86_64.debug #1
[   49.784471] Call Trace:
[   49.784512]  [<ffffffff812abe83>] debug_smp_processor_id+0x123/0x150
[   49.784520]  [<ffffffffa009043a>] enqueue_cmd_and_start_io+0x5a/0x100
[hpsa]
[   49.784529]  [<ffffffffa00905cb>]
hpsa_scsi_do_simple_cmd_core+0xeb/0x110 [hpsa]
[   49.784537]  [<ffffffff812b09c8>] ? swiotlb_dma_mapping_error+0x18/0x30
[   49.784544]  [<ffffffff812b09c8>] ? swiotlb_dma_mapping_error+0x18/0x30
[   49.784553]  [<ffffffffa0090701>]
hpsa_scsi_do_simple_cmd_with_retry+0x91/0x280 [hpsa]
[   49.784562]  [<ffffffffa0093558>]
hpsa_scsi_do_report_luns.clone.2+0xd8/0x130 [hpsa]
[   49.784571]  [<ffffffffa00935ea>]
hpsa_gather_lun_info.clone.3+0x3a/0x1a0 [hpsa]
[   49.784580]  [<ffffffffa00963df>] hpsa_update_scsi_devices+0x11f/0x4f0
[hpsa]
[   49.784592]  [<ffffffff81592019>] ? sub_preempt_count+0xa9/0xe0
[   49.784601]  [<ffffffffa00968ad>] hpsa_scan_start+0xfd/0x150 [hpsa]
[   49.784613]  [<ffffffff8158cba8>] ? rt_spin_lock_slowunlock+0x78/0x90
[   49.784626]  [<ffffffff813b04d7>] do_scsi_scan_host+0x37/0xa0
[   49.784632]  [<ffffffff813b05da>] do_scan_async+0x1a/0x30
[   49.784643]  [<ffffffff8107c4ab>] async_run_entry_fn+0x9b/0x1d0
[   49.784655]  [<ffffffff8106ae92>] process_one_work+0x1f2/0x620
[   49.784661]  [<ffffffff8106ae20>] ? process_one_work+0x180/0x620
[   49.784668]  [<ffffffff8106d4fe>] ? worker_thread+0x5e/0x3a0
[   49.784674]  [<ffffffff8107c410>] ? async_schedule+0x20/0x20
[   49.784681]  [<ffffffff8106d5d3>] worker_thread+0x133/0x3a0
[   49.784688]  [<ffffffff8106d4a0>] ? manage_workers+0x190/0x190
[   49.784696]  [<ffffffff81073236>] kthread+0xa6/0xb0
[   49.784707]  [<ffffffff815970a4>] kernel_thread_helper+0x4/0x10
[   49.784715]  [<ffffffff81082a7c>] ? finish_task_switch+0x8c/0x110
[   49.784721]  [<ffffffff8158e44b>] ? _raw_spin_unlock_irq+0x3b/0x70
[   49.784727]  [<ffffffff8158e85d>] ? retint_restore_args+0xe/0xe
[   49.784734]  [<ffffffff81073190>] ? kthreadd+0x1e0/0x1e0
[   49.784739]  [<ffffffff815970a0>] ? gs_change+0xb/0xb

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

This is caused by
enqueue_cmd_and_start_io()->
        set_performant_mode()->
                smp_processor_id()
Which if you have debugging enabled calls debug_processor_id() and triggers the warning.

The code here is
 c->Header.ReplyQueue = smp_processor_id() % h->nreply_queues;

Since it is not critical that the code complete on the same processor,
but the cpu is a hint used in generating the ReplyQueue and will still work if
the cpu migrates or is preempted, it is safe to use the raw_smp_processor_id()
to surpress the false positve warning.

Signed-off-by: John Kacur <jkacur@redhat.com>
Acked-by: Stephen Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-26 18:53:50 +04:00
..
accessibility printk: move braille console support into separate braille.[ch] files 2013-07-31 14:41:03 -07:00
acpi ACPI: Try harder to resolve _ADR collisions for bridges 2013-08-07 22:55:00 +02:00
amba
ata pata_imx: expose module alias for loading from device-tree 2013-07-29 12:13:08 -04:00
atm
auxdisplay
base regmap: cache: Make sure to sync the last register in a block 2013-08-05 15:51:09 +01:00
bcma
block Merge branch 'for-3.11/drivers' of git://git.kernel.dk/linux-block 2013-07-22 19:02:52 -07:00
bluetooth Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2013-07-31 15:11:50 -04:00
bus
cdrom
char More virtio console fixes than I'm happy with, but all real issues, 2013-08-08 09:32:20 -07:00
clk
clocksource
connector
cpufreq cpufreq: rename ignore_nice as ignore_nice_load 2013-08-07 22:25:06 +02:00
cpuidle Revert "cpuidle: Quickly notice prediction failure for repeat mode" 2013-07-29 13:32:29 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2013-07-24 11:05:18 -07:00
dca
devfreq
dio
dma ARM: SoC fixes for v3.11-rc 2013-08-08 09:28:08 -07:00
edac EDAC: Fix lockdep splat 2013-07-23 16:01:28 -07:00
eisa
extcon
firewire firewire: fix libdc1394/FlyCap2 iso event regression 2013-07-27 20:24:36 +02:00
firmware dmi_scan: add comments on dmi_present() and the loop in dmi_scan_machine() 2013-07-31 14:41:02 -07:00
fmc
gpio gpio_msm: Fix build error due to missing err.h 2013-07-31 00:34:31 +02:00
gpu Merge tag 'drm-intel-fixes-2013-08-08' of git://people.freedesktop.org/~danvet/drm-intel into drm-fixes 2013-08-09 09:09:37 +10:00
hid Revert "HID: hid-logitech-dj: querying_devices was never set" 2013-08-09 11:34:19 +02:00
hsi
hv Drivers: hv: balloon: Do not post pressure status if interrupted 2013-07-16 23:19:19 -07:00
hwmon hwmon: (adt7470) Fix incorrect return code check 2013-08-08 12:43:07 -07:00
hwspinlock
i2c i2c: Fix Kontron PLD prescaler calculation 2013-08-05 10:31:18 +02:00
ide
idle
iio iio: ti_am335x_adc: Fix wrong samples received on 1st read 2013-07-21 18:27:35 +01:00
infiniband [SCSI] IB/iser: Add Discovery support 2013-08-26 18:53:49 +04:00
input
iommu
ipack
irqchip
isdn
leds
lguest
macintosh powerpc/windfarm: Fix noisy slots-fan on Xserve (rm31) 2013-08-01 13:11:47 +10:00
mailbox
md [SCSI] Return ENODATA on medium error 2013-08-23 12:54:53 -04:00
media Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2013-08-09 15:04:09 -07:00
memory
memstick
message
mfd
misc Char/Misc patches for 3.11-rc3 2013-07-26 11:36:12 -07:00
mmc ARM: pxa: propagate errors from regulator_enable() to pxamci 2013-07-23 12:15:15 -07:00
mtd
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-08-03 15:00:23 -07:00
nfc
ntb
nubus
of of/irq: init struct resource to 0 in of_irq_to_resource() 2013-07-22 19:40:38 +01:00
oprofile
parisc parisc: Fix interrupt routing for C8000 serial ports 2013-07-31 23:42:32 +02:00
parport
pci ACPI: Try harder to resolve _ADR collisions for bridges 2013-08-07 22:55:00 +02:00
pcmcia
pinctrl pinctrl: fix a memleak when freeing maps 2013-07-25 17:18:36 +02:00
platform
pnp PNP / ACPI: avoid garbage in resource name 2013-07-18 01:38:59 +02:00
power
pps
ps3
ptp
pwm
rapidio rapidio: fix use after free in rio_unregister_scan() 2013-07-31 14:41:02 -07:00
regulator
remoteproc
reset
rpmsg
rtc drivers/rtc/rtc-twl.c: fix: rtcX/wakealarm attribute isn't created 2013-07-31 14:41:03 -07:00
s390 s390/dasd: fix hanging devices after path events 2013-07-30 16:17:25 +02:00
sbus
scsi [SCSI] hpsa: fix warning with smp_processor_id() in preemptible 2013-08-26 18:53:50 +04:00
sfi
sh
sn
spi spi: spi-davinci: Fix direction in dma_map_single() 2013-07-29 20:27:54 +01:00
ssb
staging staging: zcache: fix "zcache=" kernel parameter 2013-07-29 11:45:09 -07:00
target
tc
thermal Thermal: Fix lockup of cpu_down() 2013-07-22 09:34:46 +08:00
tty parisc: Fix interrupt routing for C8000 serial ports 2013-07-31 23:42:32 +02:00
uio
usb usb: xhci: add missing dma-mapping.h includes 2013-07-31 11:27:18 -07:00
uwb
vfio vfio-pci: Avoid deadlock on remove 2013-07-24 16:36:41 -06:00
vhost vhost: more fixes for 3.11 2013-07-23 14:38:20 -07:00
video fbdev fixes: 2013-08-09 11:52:34 -07:00
virt
virtio
vlynq
vme
w1
watchdog
xen Fixes: 2013-07-31 11:37:43 -07:00
zorro
Kconfig
Makefile