The timer migration expiry check should prevent the migration of a
timer to another CPU when the timer expires before the next event is
scheduled on the other CPU. Migrating the timer might delay it because
we can not reprogram the clock event device on the other CPU. But the
code implementing that check has two flaws:
- for !HIGHRES the check compares the expiry value with the clock
events device expiry value which is wrong for CLOCK_REALTIME based
timers.
- the check is racy. It holds the hrtimer base lock of the target CPU,
but the clock event device expiry value can be modified
nevertheless, e.g. by an timer interrupt firing.
The !HIGHRES case is easy to fix as we can enqueue the timer on the
cpu which was selected by the load balancer. It runs the idle
balancing code once per jiffy anyway. So the maximum delay for the
timer is the same as when we keep the tick on the current cpu going.
In the HIGHRES case we can get the next expiry value from the hrtimer
cpu_base of the target CPU and serialize the update with the cpu_base
lock. This moves the lock section in hrtimer_interrupt() so we can set
next_event to KTIME_MAX while we are handling the expired timers and
set it to the next expiry value after we handled the timers under the
base lock. While the expired timers are processed timer migration is
blocked because the expiry time of the timer is always <= KTIME_MAX.
Also remove the now useless clockevents_get_next_event() function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The timer migration code needs to check whether the expiry time of the
timer is before the programmed clock event expiry time when the timer
is enqueued on another CPU because we can not reprogram the timer
device on the other CPU. The current logic checks the expiry time even
if we enqueue on the current CPU when nohz_get_load_balancer() returns
current CPU. This might lead to an endless loop in the expiry check
code when the expiry time of the timer is before the current
programmed next event.
Check whether nohz_get_load_balancer() returns current CPU and skip
the expiry check if this is the case.
The bug was triggered from the networking code. The patch fixes the
regression http://bugzilla.kernel.org/show_bug.cgi?id=13738
(Soft-Lockup/Race in networking in 2.6.31-rc1+195)
Cc: Arun Bharadwaj <arun@linux.vnet.ibm.com
Tested-by: Joao Correia <joaomiguelcorreia@gmail.com>
Tested-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When the kernel is configured with CONFIG_TIMER_STATS but timer
stats are runtime disabled we still get calls to
__timer_stats_timer_set_start_info which initializes some
fields in the corresponding struct timer_list.
So add some quick checks in the the timer stats setup functions
to avoid function calls to __timer_stats_timer_set_start_info
when timer stats are disabled.
In an artificial workload that does nothing but playing ping
pong with a single tcp packet via loopback this decreases cpu
consumption by 1 - 1.5%.
This is part of a modified function trace output on SLES11:
perl-2497 [00] 28630647177732388 [+ 125]: sk_reset_timer <-tcp_v4_rcv
perl-2497 [00] 28630647177732513 [+ 125]: mod_timer <-sk_reset_timer
perl-2497 [00] 28630647177732638 [+ 125]: __timer_stats_timer_set_start_info <-mod_timer
perl-2497 [00] 28630647177732763 [+ 125]: __mod_timer <-mod_timer
perl-2497 [00] 28630647177732888 [+ 125]: __timer_stats_timer_set_start_info <-__mod_timer
perl-2497 [00] 28630647177733013 [+ 93]: lock_timer_base <-__mod_timer
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mustafa Mesanovic <mustafa.mesanovic@de.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <20090623153811.GA4641@osiris.boeblingen.de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin: (27 commits)
Blackfin: fix dma-mapping build errors
Blackfin: hook up new perf_counter_open syscall
Blackfin: drop BF535-specific text for exception 0x2A (unaligned instruction)
Blackfin: fix early crash when booting on wrong cpu
Blackfin: fix GPTMR0_CLOCKSOURCE dependency on BFIN_GPTIMERS
Blackfin: drop unused ISP1760 port1_disable from board resources
Blackfin: bf526-ezbrd: handle different SDRAM chips
Blackfin: fix typo in TRAS define in mem_init.h header
Blackfin: unify memory map headers
Blackfin: stick the CPU name into boot image name
Blackfin: update defconfigs
Blackfin: decouple unrelated cache settings to get exact behavior
Blackfin: update I-pipe patch level
Blackfin: remove obsolete mcount support from I-pipe code
Blackfin: allow CONFIG_TICKSOURCE_GPTMR0 with interrupt pipeline
Blackfin: convert interrupt pipeline to irqflags
Blackfin: allow people to select BF51x-0.1 silicon rev
Blackfin: bf526-ezbrd: set SPI flash resources to SST device
Blackfin: fix accidental reset in some boot modes
Blackfin: abstract irq14 lowering in do_irq
...
* git://git.infradead.org/~dwmw2/iommu-2.6.31:
intel-iommu: Fix one last ia64 build problem in Pass Through Support
VT-d: support the device IOTLB
VT-d: cleanup iommu_flush_iotlb_psi and flush_unmaps
VT-d: add device IOTLB invalidation support
VT-d: parse ATSR in DMA Remapping Reporting Structure
PCI: handle Virtual Function ATS enabling
PCI: support the ATS capability
intel-iommu: dmar_set_interrupt return error value
intel-iommu: Tidy up iommu->gcmd handling
intel-iommu: Fix tiny theoretical race in write-buffer flush.
intel-iommu: Clean up handling of "caching mode" vs. IOTLB flushing.
intel-iommu: Clean up handling of "caching mode" vs. context flushing.
VT-d: fix invalid domain id for KVM context flush
Fix !CONFIG_DMAR build failure introduced by Intel IOMMU Pass Through Support
Intel IOMMU Pass Through Support
Fix up trivial conflicts in drivers/pci/{intel-iommu.c,intr_remapping.c}
As noted in the previous patch, the NFSv4 client mount code currently
has several limitations. If the mount path contains symlinks, or
referrals, or even if it just contains a '..', then the client code in
nfs4_path_walk() will fail with an error.
This patch replaces the nfs4_path_walk()-based lookup with a helper
function that sets up a private namespace to represent the namespace on the
server, then uses the ordinary VFS and NFS path lookup code to walk down the
mount path in that namespace.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The purpose of this patch is to improve the remote mount path lookup
support for distributed filesystems such as the NFSv4 client.
When given a mount command of the form "mount server:/foo/bar /mnt", the
NFSv4 client is required to look up the filehandle for "server:/", and
then look up each component of the remote mount path "foo/bar" in order
to find the directory that is actually going to be mounted on /mnt.
Following that remote mount path may involve following symlinks,
crossing server-side mount points and even following referrals to
filesystem volumes on other servers.
Since the standard VFS path lookup code already supports walking paths
that contain all these features (using in-kernel automounts for
following referrals) we would like to be able to reuse that rather than
duplicate the full path traversal functionality in the NFSv4 client code.
This patch therefore defines a VFS helper function create_mnt_ns(), that
sets up a temporary filesystem namespace and attaches a root filesystem to
it. It exports the create_mnt_ns() and put_mnt_ns() function for use by
filesystem modules.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to allow modules to use it without having to export vfsmount_lock.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SLAB uses get/put_online_cpus() which use a mutex which is itself only
initialized when cpu_hotplug_init() is called. Currently we hang suring
boot in SLAB due to doing that too late.
Reported by James Bottomley and Sachin Sant (and possibly others).
Debugged by Benjamin Herrenschmidt.
This just removes the dynamic initialization of the data structures, and
replaces it with a static one, avoiding this dependency entirely, and
removing one unnecessary special initcall.
Tested-by: Sachin Sant <sachinp@in.ibm.com>
Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The recent deprecation of dma_sync_{sg,single} ironically broke Blackfin
systems. This is because we don't define dma_sync_sg_for_cpu at all, so
until the DMA asm-generic conversion/cleanup is done after the next
release, simply stub out the dma_sync_sg_for_{cpu,device} functions.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We don't support the BF535 at all, and the exception 0x2A text specific to
it is pretty verbose and confusing (since the behavior is simply odd), so
punt it to keep the noise down.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Make sure we process the kernel command line before poking the hardware,
so that we can process early printk. This helps ensure that if you boot
a kernel configured for a different processor, something will be left in
the log buffer.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The GPTMR0_CLOCKSOURCE Kconfig option requires the gptimers framework, so
make sure it is selected when this option is enabled.
Reported-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The BF526-EZBRD changed SDRAM chips between board revisions, so create a
timing table that can accommodate both.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We defined SDRAM_tRAS to TRAS_4, but then wrongly defined SDRAM_tRAS_num
to 3.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Many aspects of the Blackfin memory map is exactly the same across all
variants. Rather than copy and paste all of these duplicated values in
each header, unify all of these into the common Blackfin memory map header
file. In the process, push down BF561 SMP specific stuff to the BF561
specific header to keep the noise down.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Rather than use "Linux" in the boot image name (as this is redundant --
the image type is already set to "linux"), use the CPU name. This makes
it fairly obvious when a wrong image is accidentally booted. Otherwise
there is no kernel output and you waste time scratching your head
wondering wtf just happened.
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The current cache options don't really represent the hardware features.
They end up setting different aspects of the hardware so that the end
result is to turn on/off the cache. Unfortunately, when we hit cache
problems with the hardware, it's difficult to test different settings to
root cause the problem. The current settings also don't cleanly allow for
different caching behaviors with different regions of memory.
So split the configure options such that they properly reflect the settings
that are applied to the hardware.
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The BF526-EZBRD has a SST SPI flash on it, not a ST Micro.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We read the SWRST (Software Reset) register to get at the last reset
state, and then we may configure the DOUBLE_FAULT bit to control behavior
when a double fault occurs. But if the lower bits of the register is
already set (like UART boot mode on a BF54x), we inadvertently make the
system reset by writing to the SYSTEM_RESET field at the same time. So
make sure the lower 4 bits are always cleared.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Split out the optional IRQ14 lowering code to further simplify the
asm_do_IRQ() function and keep the ifdef nest under control.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Take a page from x86 and abstract the stack checking out of the
asm_do_IRQ() function so that the result is easier to digest.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
With the common IRQ code initializing much more of the irq_desc state, we
can't blindly initialize it ourselves to the local bad_irq state. If we
do, we end up wrongly clobbering many fields. So punt most of the bad irq
code as the common layers will handle the default state, and simply call
handle_bad_irq() directly when the IRQ we are processing is invalid.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The BF533-EZKIT has two Flash In-System Programming devices hooked up to
the async memory bus, so add resources for the primary flashes and the
SRAMs on the devices.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The kgdb (in multiple places) and traps code developed pretty much
identical checks for how to access different regions of the Blackfin
memory map, but each wasn't 100%, so unify them to avoid duplication,
bitrot, and bugs with edge cases.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
* git://git.infradead.org/mtd-2.6: (63 commits)
mtd: OneNAND: Allow setting of boundary information when built as module
jffs2: leaking jffs2_summary in function jffs2_scan_medium
mtd: nand: Fix memory leak on txx9ndfmc probe failure.
mtd: orion_nand: use burst reads with double word accesses
mtd/nand: s3c6400 support for s3c2410 driver
[MTD] [NAND] S3C2410: Use DIV_ROUND_UP
[MTD] [NAND] S3C2410: Deal with unaligned lengths in S3C2440 buffer read/write
[MTD] [NAND] S3C2410: Allow the machine code to get the BBT table from NAND
[MTD] [NAND] S3C2410: Added a kerneldoc for s3c2410_nand_set
mtd: physmap_of: Add multiple regions and concatenation support
mtd: nand: max_retries off by one in mxc_nand
mtd: nand: s3c2410_nand_setrate(): use correct macros for 2412/2440
mtd: onenand: add bbt_wait & unlock_all as replaceable for some platform
mtd: Flex-OneNAND support
mtd: nand: add OMAP2/OMAP3 NAND driver
mtd: maps: Blackfin async: fix memory leaks in probe/remove funcs
mtd: uclinux: mark local stuff static
mtd: uclinux: do not allow to be built as a module
mtd: uclinux: allow systems to override map addr/size
mtd: blackfin NFC: fix hang when using NAND on BF527-EZKITs
...
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (49 commits)
[ARM] idle: clean up pm_idle calling, obey hlt_counter
[ARM] S3C: Fix gpio-config off-by-one bug
[ARM] S3C64XX: add to_irq() support for EINT() GPIO
[ARM] S3C64XX: clock.c: fix typo in usb-host clock ctrlbit
[ARM] S3C64XX: fix HCLK gate defines
[ARM] Update mach-types
[ARM] wire up rt_tgsigqueueinfo and perf_counter_open
OMAP2 clock/powerdomain: off by 1 error in loop timeout comparisons
OMAP3 SDRC: set FIXEDDELAY when disabling SDRC DLL
OMAP3: Add support for DPLL3 divisor values higher than 2
OMAP3 SRAM: convert SRAM code to use macros rather than magic numbers
OMAP3 SRAM: add more comments on the SRAM code
OMAP3 clock/SDRC: program SDRC_MR register during SDRC clock change
OMAP3 clock: add a short delay when lowering CORE clk rate
OMAP3 clock: initialize SDRC timings at kernel start
OMAP3 clock: remove wait for DPLL3 M2 clock to stabilize
[ARM] Add old Feroceon support to compressed/head.S
[ARM] 5559/1: Limit the stack unwinding caused by a kthread exit
[ARM] 5558/1: Add extra checks to ARM unwinder to avoid tracing corrupt stacks
[ARM] 5557/1: Discard some ARM.ex*.*exit.text sections when !HOTPLUG or !HOTPLUG_CPU
...
pm_idle is used by infrastructure (eg, cpuidle) which expects architectures
to call it in a certain way. Arrange for ARM to follow x86's lead on this
and call pm_idle() with interrupts already disabled. However, we expect
pm_idle() to enable interrupts before it returns.
Also, OMAP wants to be able to disable hlt-ing, so allow hlt_counter to
prevent all calls to pm_idle.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix the MN10300 vmlinux ldscript. It needs to use various macros from
asm-generic/vmlinux.lds.h to correctly include all that it needs to.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In asm-generic/vmlinux.lds.h, name INIT_RAM_FS consistently, no matter the
setting of CONFIG_BLK_DEV_INITRD. This corrects:
commit ef53dae865
Author: Sam Ravnborg <sam@ravnborg.org>
Date: Sun Jun 7 20:46:37 2009 +0200
Subject: Improve vmlinux.lds.h support for arch specific linker scripts
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-2.6.31' of git://fieldses.org/git/linux-nfsd: (60 commits)
SUNRPC: Fix the TCP server's send buffer accounting
nfsd41: Backchannel: minorversion support for the back channel
nfsd41: Backchannel: cleanup nfs4.0 callback encode routines
nfsd41: Remove ip address collision detection case
nfsd: optimise the starting of zero threads when none are running.
nfsd: don't take nfsd_mutex twice when setting number of threads.
nfsd41: sanity check client drc maxreqs
nfsd41: move channel attributes from nfsd4_session to a nfsd4_channel_attr struct
NFS: kill off complicated macro 'PROC'
sunrpc: potential memory leak in function rdma_read_xdr
nfsd: minor nfsd_vfs_write cleanup
nfsd: Pull write-gathering code out of nfsd_vfs_write
nfsd: track last inode only in use_wgather case
sunrpc: align cache_clean work's timer
nfsd: Use write gathering only with NFSv2
NFSv4: kill off complicated macro 'PROC'
NFSv4: do exact check about attribute specified
knfsd: remove unreported filehandle stats counters
knfsd: fix reply cache memory corruption
knfsd: reply cache cleanups
...
* 'for-2.6.31' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (128 commits)
nfs41: sunrpc: xprt_alloc_bc_request() should not use spin_lock_bh()
nfs41: Move initialization of nfs4_opendata seq_res to nfs4_init_opendata_res
nfs: remove unnecessary NFS_INO_INVALID_ACL checks
NFS: More "sloppy" parsing problems
NFS: Invalid mount option values should always fail, even with "sloppy"
NFS: Remove unused XDR decoder functions
NFS: Update MNT and MNT3 reply decoding functions
NFS: add XDR decoder for mountd version 3 auth-flavor lists
NFS: add new file handle decoders to in-kernel mountd client
NFS: Add separate mountd status code decoders for each mountd version
NFS: remove unused function in fs/nfs/mount_clnt.c
NFS: Use xdr_stream-based XDR encoder for MNT's dirpath argument
NFS: Clean up MNT program definitions
lockd: Don't bother with RPC ping for NSM upcalls
lockd: Update NSM state from SM_MON replies
NFS: Fix false error return from nfs_callback_up() if ipv6.ko is not available
NFS: Return error code from nfs_callback_up() to user space
NFS: Do not display the setting of the "intr" mount option
NFS: add support for splice writes
nfs41: Backchannel: CB_SEQUENCE validation
...
