The RT team has been searching for a nasty latency. This latency shows
up out of the blue and has been seen to be as big as 5ms!
Using ftrace I found the cause of the latency.
pcscd-2995 3dNh1 52360300us : irq_exit (smp_apic_timer_interrupt)
pcscd-2995 3dN.2 52360301us : idle_cpu (irq_exit)
pcscd-2995 3dN.2 52360301us : rcu_irq_exit (irq_exit)
pcscd-2995 3dN.1 52360771us : smp_apic_timer_interrupt (apic_timer_interrupt
)
pcscd-2995 3dN.1 52360771us : exit_idle (smp_apic_timer_interrupt)
Here's an example of a 400 us latency. pcscd took a timer interrupt and
returned with "need resched" enabled, but did not reschedule until after
the next interrupt came in at 52360771us 400us later!
At first I thought we somehow missed a preemption check in entry.S. But
I also noticed that this always seemed to happen during a __delay call.
pcscd-2995 3dN.2 52360836us : rcu_irq_exit (irq_exit)
pcscd-2995 3.N.. 52361265us : preempt_schedule (__delay)
Looking at the x86 delay, I found my problem.
In git commit 35d5d08a08, Andrew Morton
placed preempt_disable around the entire delay due to TSC's not working
nicely on SMP. Unfortunately for those that care about latencies this
is devastating! Especially when we have callers to mdelay(8).
Here I enable preemption during the loop and account for anytime the task
migrates to a new CPU. The delay asked for may be extended a bit by
the migration, but delay only guarantees that it will delay for that minimum
time. Delaying longer should not be an issue.
[
Thanks to Thomas Gleixner for spotting that cpu wasn't updated,
and to place the rep_nop between preempt_enabled/disable.
]
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: akpm@osdl.org
Cc: Clark Williams <clark.williams@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Luis Claudio R. Goncalves" <lclaudio@uudg.org>
Cc: Gregory Haskins <ghaskins@novell.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <andi-suse@firstfloor.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
for http://bugzilla.kernel.org/show_bug.cgi?id=10613
BIOS bug, APIC version is 0 for CPU#0! fixing up to 0x10. (tell your hw vendor)
v2: fix 64 bit compilation
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Gabriel C <nix.or.die@googlemail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Since mmc_spi.h uses irqreturn_t type, it should include appropriate
header, otherwise build will break if users didn't include it (some of
them do not use interrupts).
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6:
8250 Serial Driver: revert extra IRQ flag definition patch
Blackfin arch: update anomaly headers from toolchain trunk
Blackfin arch: Remove bad and usless code
Blackfin arch: Fix bug - set corret SSEL and IRQ to enable AD7877 on BF527
Blackfin arch: Fix typo. it should be _outsw_8
Blackfin arch: Cleanup no functional changes
When we introduced support for KBUILD_EXTRA_SYMBOLS
we started to include the externam module's kbuild
file when doing the final modpost step.
As external modules often do:
ccflags-y := -I$(src)
We had problems because $(src) was unassinged and
gcc then used the next parameter for -I resulting in
strange build failures.
Fix is to assign $(src) and $(obj) when building
external modules.
This fixes: http://bugzilla.kernel.org/show_bug.cgi?id=10798
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Tvrtko <tvrtko.ursulin@sophos.com>
Cc: Andrea Arcangeli <andrea@qumranet.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
As Russell pointed out, original patch will break some serial configurations
because of the dependency of the <asm/serial.h> header file.
Revert it first and try to find out other solution later
Cc: Javier Herrero <jherrero@hvsistemas.es>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
AD7877 use SSEL_2 (P9.9) and IRQ_PF8 (P9.14) on BF527
- populating JP3 to enable STAMP
- disable SW11.2 to disconnect SSEL_2/PF12 from Rotary NAND
- disable SW18.1 to disconnect SSEL_2 from MAX1233 touchscreen chip
Signed-off-by: Bryan Wu <cooloney@kernel.org>
The node for DMA2 in the MPC8610 HPCD device tree has the wrong compatible
properties. This breaks the DMA driver and the sound driver.
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently ext4 and fuse fail to link if modular:
ERROR: "copy_page" [fs/fuse/fuse.ko] undefined!
ERROR: "empty_zero_page" [fs/ext4/ext4dev.ko] undefined!
make[3]: *** [__modpost] Error 1
make[2]: *** [modules] Error 2
make[1]: *** [sub-make] Error 2
While arch ppc exists it may as well compile, so this exports those
symbols (which are already exported in arch/powerpc).
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Gcc might re-order MMIO accessors vs. surrounding consistent
memory accesses, which is a "bad thing", and could break drivers.
This fixes it by adding a "memory" clobber to the MMIO accessors,
which should prevent gcc from doing that reordering.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch silences the build warnings concerning o2net_init_nst()
and friends when building without CONFIG_DEBUG_FS enabled.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch silences the build warnings concerning dlm_debug_init()
and friends when building without CONFIG_DEBUG_FS enabled.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch silences the build warnings concerning o2net_debugfs_init()
and friends when building without CONFIG_DEBUG_FS enabled.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The static structure describing the userspace cluster plugin for ocfs2
was named 'user_stack', which is a real pain when people are grep(1)ing
the tree for the program stack object 'user_stack'. Change the name to
something distinct and namespaced.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
lguest: notify on empty
virtio: force callback on empty.
virtio_blk: fix endianess annotations
virtio_config: fix len calculation of config elements
virtio_net: another race with virtio_net and enable_cb
virtio: An entropy device, as suggested by hpa.
virtio_blk: allow read-only disks
lguest: fix ugly <NULL> in /proc/interrupts
virtio: set device index in common code.
virtio: virtio_pci should not set bus_id.
virtio: bus_id for devices should contain 'virtio'
Fix crash in virtio_blk during modprobe ; rmmod ; modprobe
lguest: use ioremap_cache, not ioremap
* Wim Van Sebroeck <wim@iguana.be> wrote:
> Author: Jordan Crouse <jordan.crouse@amd.com>
> Date: Mon Jan 21 10:07:00 2008 -0700
>
> [WATCHDOG] Add a watchdog driver based on the CS5535/CS5536 MFGPT timers
-tip testing found the following build failure on latest -git:
drivers/watchdog/geodewdt.c: In function 'geodewdt_probe':
drivers/watchdog/geodewdt.c:225: error: too many arguments to function 'geode_mfgpt_alloc_timer'
make[1]: *** [drivers/watchdog/geodewdt.o] Error 1
make: *** [drivers/watchdog/geodewdt.o] Error 2
with this config:
http://redhat.com/~mingo/misc/config-Fri_May_30_15_19_52_CEST_2008.bad
find the fix below.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When Greg "fixed" the sysfs usage of that driver a while back, he seem
to have introduced a bug where the quotes are added around the name of
our specific sysfs files, thus breaking the user space tool.
This fixes it. Tested DLPAR operations on a POWER6 machine successfully.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Change the partial Device IDs of nvidia MCP7B AHCI controller in ahci.c,
as the actual PCI IDs deployed in the field differed from the forecasted ones
preemptively placed in the driver.
Signed-off-by: Peer Chen <peerchen@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
The following commit (4c9bf4e799):
libata: replace tf_read with qc_fill_rtf for non-SFF drivers
Broke the sata_fsl.c driver in 2.6.26-rc. I know the following patch fixes
the issue, it clearly also adds port multipler support. The current
2.6.26-rc driver is broken.
On boot with debug enabled we get something like (w/o this patch):
spurious interrupt!!, CC = 0x1
interrupt status 0x1
xx_scr_read, reg_in = 1
spurious interrupt!!, CC = 0x1
interrupt status 0x1
xx_scr_read, reg_in = 1
spurious interrupt!!, CC = 0x1
interrupt status 0x1
xx_scr_read, reg_in = 1
.. continues for ever.
This change fixes this as a side effect of adding port multiplier support.
Signed-off-by: Ashish Kalra <ashish.kalra@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
As in sil4726, SRST can't be trusted on sil3726 causing detection
problems under certain configuraitons. I thought it was from the
Config Disk device but apparently not.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Fix libata-scsi kernel-doc notation:
Warning(linux-2.6.25-git15//drivers/ata/libata-scsi.c:1659): No description found for parameter 'cmd'
Warning(linux-2.6.25-git15//drivers/ata/libata-scsi.c:1971): No description found for parameter 'buf'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
ICH8M on macbooks are peculiar in that some of them lock up when the
second port is enabled, some return bogus values on SIDPR access while
yet others hang on SIDPR access. Also, the ich8m_apple_sata entry was
wrongly added below generic ich8m entry making it virtually useless.
This patch works around macbook ich8m problems by
* moving ich8m_apple_sata entry above generic ich8m entry
* dropping PIIX_FLAG_SIDPR from ich8m_apple_sata
* adding subsystem 106b:00a1 as ich8m_apple_sata
Reported and tested by MATSUBAYASHI.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: MATSUBAYASHI 'Shaolin' Kohji <shaolin@rhythmaning.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
The 5182 System-On-Chip (SOC) variant wants certain lower
bits to be cleared on any write to the PHY_MODE3 register.
If/when support is added for other SOC variants, we'll need
some way to uniquely identify the 5182, and not perform this
workaround for the others.
But for now, it is the only SOC variant we support here.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
The "B2" variant of the 6041/6081 (genII) chips requires
that the PHY_MODE3 register be rewritten after any write
to PHY_MODE4.
This fixes a regression introduced by an earlier patch.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
The only public release of the 6042/7042 chips was/is revision "B0".
Remove code that attempted to deal with earlier, non-released revs.
This matches the logic of the current Marvell "proprietary" driver.
Also, bump up the sata_mv version number, to reflect this batch of erratas.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Fix and update the errata handling for the PHY_MODEx registers.
This improves receiver noise tolerance, among other things.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Convert the System-on-Chip flag from a host flag to an hpriv flag,
for better consistency with other chip-rev flags, and for easier use
in errata fixes etc.
Also change the related "HAS_PCI()" into "!IS_SOC()" for better consistency
of naming/use (everything else SOC-related already uses "SOC").
There are no functionality changes in this patch.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
[S390] Update default configuration.
[S390] disassembler: fix idte instruction format.
[S390] tape: fix race with stack local wait_queue_head_t.
[S390] 3270: fix race with stack local wait_queue_head_t.
[S390] dasd: use a generic wait_queue for sleep_on
[S390] sclp_vt220: fix scheduling while atomic bug.
[S390] showmem: Only walk spanned pages.
[S390] appldata: prevent cpu hotplug when walking cpu_online_map.
[S390] Fix section mismatch warnings.
[S390] s390 types: make dma_addr_t 64 bit capable
[S390] tape: Fix race condition in tape block device driver
[S390] fix sparsemem related compile error with allnoconfig on s390
In this case we want a constant pointer to constant chars:
drivers/misc/thinkpad_acpi.c:3824:19: error: Just how const do you want this type to be?
Like the error says.
drivers/misc/thinkpad_acpi.c:3863:19: error: Just how const do you want this type to be?
drivers/misc/thinkpad_acpi.c:3864:19: error: Just how const do you want this type to be?
drivers/misc/thinkpad_acpi.c:3865:19: error: Just how const do you want this type to be?
drivers/misc/thinkpad_acpi.c:3866:19: error: Just how const do you want this type to be?
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The SW_RADIO code for EV_SW events has a name that is not descriptive
enough of its intended function, and could induce someone to think
KEY_RADIO is its EV_KEY counterpart, which is false.
Rename it to SW_RFKILL_ALL, and document what this event is for. Keep
the old name around, to avoid userspace ABI breaks.
The SW_RFKILL_ALL event is meant to be used by rfkill master switches. It
is not bound to a particular radio switch type, and usually applies to all
types. It is semantically tied to master rfkill switches that enable or
disable every radio in a system.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
The code would try to free 'report' twice upon input_register_device()
failure.
Reported-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
llc_sap_rcv was being preceded by skb_set_owner_r, then calling
llc_state_process that calls sock_queue_rcv_skb, that in turn calls
skb_set_owner_r again making the space allowed to be used by the socket to be
leaked, making the socket to get stuck.
Fix it by setting skb->sk at llc_sap_rcv and leave the accounting to be done
only at sock_queue_rcv_skb.
Reported-by: Dmitry Petukhov <dmgenp@gmail.com>
Tested-by: Dmitry Petukhov <dmgenp@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The correct instruction format of idte is "idte r1,r3,r2" with
r1 at bit 24, r3 at bit 16 and r2 at bit 28.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A wait_event call with a stack local wait_queue_head_t structure that is
used to do the wake up for the wait_event is inherently racy. After the
wait_event finished the wake_up call might not have completed yet.
Replace the stack local wait_queue_head_t in tape_do_io and
tape_do_io_interruptible with a per device wait queue.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
A wait_event call with a stack local wait_queue_head_t structure that is
used to do the wake up for the wait_event is inherently racy. After the
wait_event finished the wake_up call might not have completed yet.
Remove the stack local wait_queue_head_t from raw3270_start_init and
use the global raw3270_wait_queue instead.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
