To decrease the chance of a missed enable, always enable the timer when we
sample it, we'll always disable it when we find that there are no active timers
in the jiffy tick.
This fixes a flood of warnings reported by Mike Galbraith.
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Implement Linus's suggestion: introduce the hpet_cnt_ahead()
helper function to compare hpet time values - like other
wrapping counter comparisons are abstracted away elsewhere.
(jiffies, ktime_t, etc.)
Reported-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Mike Galbraith reported that the new warning in thread_group_cputimer()
triggers en masse with Amarok running.
Oleg Nesterov observed:
Can't fastpath_timer_check()->thread_group_cputimer() have the
false warning too? Suppose we had the timer, then posix_cpu_timer_del()
removes this timer, but task_cputime_zero(&sig->cputime_expires) still
not true.
Remove the spurious debug warning.
Reported-by: Mike Galbraith <efault@gmx.de>
Explained-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change the process wide cpu timers/clocks so that we:
1) don't mess up the kernel with too many threads,
2) don't have a per-cpu allocation for each process,
3) have no impact when not used.
In order to accomplish this we're going to split it into two parts:
- clocks; which can take all the time they want since they run
from user context -- ie. sys_clock_gettime(CLOCK_PROCESS_CPUTIME_ID)
- timers; which need constant time sampling but since they're
explicity used, the user can pay the overhead.
The clock readout will go back to a full sum of the thread group, while the
timers will run of a global 'clock' that only runs when needed, so only
programs that make use of the facility pay the price.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We're going to split the process wide cpu accounting into two parts:
- clocks; which can take all the time they want since they run
from user context.
- timers; which need constant time tracing but can affort the overhead
because they're default off -- and rare.
The clock readout will go back to a full sum of the thread group, for this
we need to re-add the exit stats that were removed in the initial itimer
rework (f06febc9: timers: fix itimer/many thread hang).
Furthermore, since that full sum can be rather slow for large thread groups
and we have the complete dead task stats, revert the do_notify_parent time
computation.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merging it here because an upcoming timers/urgent fix relies on
a change already in sched/urgent and not yet upstream.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There's a small problem with hpet_rtc_reinit function - it checks
for the:
hpet_readl(HPET_COUNTER) - hpet_t1_cmp > 0
to continue increasing both the HPET_T1_CMP (register) and the
hpet_t1_cmp (variable).
But since the HPET_COUNTER is always 32-bit, if the hpet_t1_cmp
is 64-bit this condition will always be FALSE once the latter hits
the 32-bit boundary, and we can have a situation, when we don't
increase the HPET_T1_CMP register high enough.
The result - timer stops ticking, since HPET_T1_CMP becomes less,
than the COUNTER and never increased again.
The solution is (based on Linus's suggestion) to not compare 64-bits
(on 64-bit x86), but to do the comparison on 32-bit signed
integers.
Reported-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Christian Borntraeger reports:
> After a logical cpu offline, even on a complete idle system, there
> is one cpu with full ticks. It turns out that nohz.cpu_mask has the
> the offlined cpu still set.
>
> In select_nohz_load_balancer() we check if the system is completely
> idle to turn of load balancing. We compare cpu_online_map with
> nohz.cpu_mask. Since cpu_online_map is updated on cpu unplug,
> but nohz.cpu_mask is not, the check fails and the scheduler believes
> that we need an "idle load balancer" even on a fully idle system.
> Since the ilb cpu does not deactivate the timer tick this breaks NOHZ.
Fix the select_nohz_load_balancer() to not set the nohz.cpu_mask
while a cpu is going offline.
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add kernel-doc notation for @lock:
include/linux/sched.h:457: No description found for parameter 'lock'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI hotplug: Change link order of pciehp & acpiphp
PCI hotplug: fakephp: Allocate PCI resources before adding the device
PCI MSI: Fix undefined shift by 32
PCI PM: Do not wait for buses in B2 or B3 during resume
PCI PM: Power up devices before restoring their state
PCI PM: Fix hibernation breakage on EeePC 701
PCI: irq and pci_ids patch for Intel Tigerpoint DeviceIDs
PCI PM: Fix suspend error paths and testing facility breakage
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
slub: fix per cpu kmem_cache_cpu array memory leak
kmalloc: return NULL instead of link failure
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
fbdev/atyfb: Fix DSP config on some PowerMacs & PowerBooks
powerpc: Fix oops on some machines due to incorrect pr_debug()
powerpc/ps3: Printing fixups for l64 to ll64 convserion drivers/net
powerpc/5200: update device tree binding documentation
powerpc/5200: Bugfix for PCI mapping of memory and IMMR
powerpc/5200: update defconfigs
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched_rt: don't use first_cpu on cpumask created with cpumask_and
sched: fix buddie group latency
sched: clear buddies more aggressively
sched: symmetric sync vs avg_overlap
sched: fix sync wakeups
cpuset: fix possible deadlock in async_rebuild_sched_domains
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
pxamci: enable DMA for write ops after CMD/RESP
pxamci: replace #ifdef CONFIG_PXA27x with if (cpu_is_pxa27x())
ricoh_mmc: Use suspend_late/resume_early
mmci: Add support for ST Micro derivate
mmc: Add a MX2/MX3 specific SDHC driver
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
icside: fix PCB version 6 support (v2)
tx4939ide: typo fix and minor cleanup
ide: add CS5536 host driver (v3)
ide: Force VIA IDE legacy interrupts for AmigaOne boards
IDE: Unregister and disable devices if initialization fails.
ide: fix ide_register_port() failure handling
ide: struct device - replace bus_id with dev_name(), dev_set_name()
ide-cd: fix DMA for non bio-backed requests
* 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/dvrabel/uwb:
uwb: lock rc->rsvs_lock with spin_lock_bh()
wusb: timeout when waiting for ASL/PZL updates in whci-hcd
uwb: remove unused #include <version.h>'s
wusb: return -ENOTCONN when resetting a port with no connected device
uwb: safely remove all reservations
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: add text file detailing queue/ sysfs files
bio.h: If they MUST be inlined, then use __always_inline
Fix misleading comment in bio.h
block: fix inconsistent parenthesisation of QUEUE_FLAG_DEFAULT
block: fix oops in blk_queue_io_stat()
The host really shouldn't be notifying us of config changes
before the device status is VIRTIO_CONFIG_S_DRIVER or
VIRTIO_CONFIG_S_DRIVER_OK.
However, if we do happen to be interrupted while we're not
attached to a driver, we really shouldn't oops. Prevent
this simply by checking that device->driver is non-NULL
before trying to notify the driver of config changes.
Problem observed by doing a "set_link virtio.0 down" with
QEMU before the net driver had been loaded.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current refcounting for modules (done if CONFIG_MODULE_UNLOAD=y) is
using a lot of memory.
Each 'struct module' contains an [NR_CPUS] array of full cache lines.
This patch uses existing infrastructure (percpu_modalloc() &
percpu_modfree()) to allocate percpu space for the refcount storage.
Instead of wasting NR_CPUS*128 bytes (on i386), we now use
nr_cpu_ids*sizeof(local_t) bytes.
On a typical distro, where NR_CPUS=8, shiping 2000 modules, we reduce
size of module files by about 2 Mbytes. (1Kb per module)
Instead of having all refcounters in the same memory node - with TLB misses
because of vmalloc() - this new implementation permits to have better
NUMA properties, since each CPU will use storage on its preferred node,
thanks to percpu storage.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the PXA270 MMC hardware, there seems to be an issue of
data corruption on writes where a 4KB data block is offset
by one byte.
If we delay enabling the DMA for writes until after the CMD/RESP
has finished, the problem seems to be fixed.
related to PXA270 Erratum #91
Tested-by: Vernon Sauder <VernonInHand@gmail.com>
Signed-off-by: Cliff Brake <cbrake@bec-systems.com>
Acked-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
If ricoh_mmc suspends before sdhci_pci, it will pull the card
out from under the controller, which could leave the system in
a very confused state.
Using suspend_late/resume_early ensures that sdhci_pci suspends first
and resumes second.
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch adds support for the ST Microelectronics version of
the PL180 PrimeCell. They use designer ID 0x80 and have a few
alterations/bugfixes related to open drain and HW flow control.
They also add some SDIO registers, I am unsure if these are
in ST HW only or if this is things also added in later ARM
revisions, but they are included in the mmci.h file for
completeness.
Signed-off-by: Linus Walleij <linus.walleij@ericsson.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch adds a MX2/MX3 specific SDHC driver. The hardware is basically
the same as in the MX1, but unlike the MX1 controller the MX2
controller just works as expected. Since the MX1 driver has more
workarounds for bugs than anything else I had no success with supporting
MX1 and MX2 in a sane way in one driver.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
We need to pass struct ide_port_info also to ide_host_register().
v2:
Fix v5/v6 mismatch noticed by Russell.
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
The bcount is greater than 0 and less than or equal to 0x10000.
Thus '(bcount & 0xffff) == 0x0000' can be simplified as 'bcount == 0x10000'.
Suggested-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
This is a port of libata's pata_cs5536.c (written by Martin K. Petersen)
to IDE subsystem.
Changes done while at it:
* Reprogram PIO/MWDMA timings if needed before and after DMA transfer
(chipset uses shared PIO/MWDMA timings).
* Fix cable detection to report 80-wires cable if BIOS set it for any
device on a port (IDE core will do drive-side cable detection later).
* Don't disable UDMA while programming PIO timings.
* Simplify PCI/MSR support.
Pros of having IDE host driver in addition to libata's one:
* IDE is much lighter than SCSI+libata, the host driver itself is also
a bit smaller:
text data bss dec hex filename
1261 496 4 1761 6e1 drivers/ata/pata_cs5536.o
1242 128 4 1374 55e drivers/ide/cs5536.o
* This allows use of IDE features which are unavailable under libata.
v2:
* Fixes per review from Sergei:
- simplify dependency check in Kconfig
- use IDE_DRV_MASK also for ->drive_data
- disable UDMA when programming MWDMA
- program new DTC timings only when necessary
- fix printk() level in cs5536_init_one()
* Fix patch description according to comments from Alan and Sergei.
v3:
* Smarter masking of UDMA bits per Sergei's suggestion.
Cc: Martin K. Petersen <mkp@mkp.net>
Cc: Karl Auerbach <karl@iwl.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
The AmigaOne uses the onboard VIA IDE controller in legacy mode (like the
Pegasos).
Signed-off-by: Gerhard Pircher <gerhard_pircher@gmx.net>
Cc: "Grant Likely" <grant.likely@secretlab.ca>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
On reboot the loop in device_shutdown gets confused by these partially
initialized devices and goes into an infinite loop. Therefore unregister
and disable these devices.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
[bart: remove leftover hwif->present clearing + update patch description]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Factor out port freeing from ide_host_free() to ide_free_port().
* Add ide_disable_port() and use it on ide_register_port() failure.
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
bvec_kmap_irq() and bvec_kunmap_irq() comments say they MUST be inlined,
so mark them as __always_inline.
Signed-off-by: Alberto Bertogli <albertito@blitiri.com.ar>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The comment says "remember to add offset!", but the function already adds
it.
Signed-off-by: Alberto Bertogli <albertito@blitiri.com.ar>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Some initial probe requests don't have disk->queue mapped yet, so we
can't rely on a non-NULL queue in blk_queue_io_stat(). Wrap it in
blk_do_io_stat().
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Since the complete re-write in 2.6.10, some PowerMacs (At least PowerMac 5500
and PowerMac G3 Beige rev A) with ATI Mach64 chip have suffered from unstable
columns in their framebuffer image. This seems to depend on a value (4) read
from PLL_EXT_CNTL register, which leads to incorrect DSP config parameters to
be written to the chip. This patch uses a value calculated by aty_init_pll_ct
instead, as a starting point.
There are questions as to whether this should be extended to other platforms
or maybe made dependent on specific chip types, but in the meantime, this has
been tested on various powermacs and works for them so let's commit it.
Signed-off-by: Risto Suominen <Risto.Suominen@gmail.com>
Tested-by: Michael Pettersson <mike@it.uu.se>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Recently, a patch left DEBUG enabled in the powerpc common PCI code,
resulting in an old bug in a pr_debug() statement to show up and cause
a NULL dereference on some machines.
This fixes the pr_debug() statement and reverts to DEBUG not being
force-enabled in that file.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This essentially reverts commit 8edb08caf6.
It downgraded our mmap semaphore to a read-lock while mlocking pages, in
order to allow other threads (and external accesses like "ps" et al) to
walk the vma lists and take page faults etc. Which is a nice idea, but
the implementation does not work.
Because we cannot upgrade the lock back to a write lock without
releasing the mmap semaphore, the code had to release the lock entirely
and then re-take it as a writelock. However, that meant that the caller
possibly lost the vma chain that it was following, since now another
thread could come in and mmap/munmap the range.
The code tried to work around that by just looking up the vma again and
erroring out if that happened, but quite frankly, that was just a buggy
hack that doesn't actually protect against anything (the other thread
could just have replaced the vma with another one instead of totally
unmapping it).
The only way to downgrade to a read map _reliably_ is to do it at the
end, which is likely the right thing to do: do all the 'vma' operations
with the write-lock held, then downgrade to a read after completing them
all, and then do the "populate the newly mlocked regions" while holding
just the read lock. And then just drop the read-lock and return to user
space.
The (perhaps somewhat simpler) alternative is to just make all the
callers of mlock_vma_pages_range() know that the mmap lock got dropped,
and just re-grab the mmap semaphore if it needs to mlock more than one
vma region.
So we can do this "downgrade mmap sem while populating mlocked regions"
thing right, but the way it was done here was absolutely not correct.
Thus the revert, in the expectation that we will do it all correctly
some day.
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Just like with the s5h1411, the s5h1409 needs a soft-reset in order for it
to know that the tuner has been told to change frequencies. This change
changes the behavior from "random tuning times between 500ms to complete
tuning lock failures" to "tuning lock consistently within 700ms".
Thanks to Robert Krakora <rob.krakora@messagenetsystems.com> for doing
initial testing of the patch on the KWorld 330U.
Thanks to Andy Walls <awalls@radix.net> for doing testing of the patch on
the HVR-1600.
Thanks to Michael Krufky <mkrufky@linuxtv.org> for doing additional testing.
Signed-off-by: Devin Heitmueller <dheitmueller@linuxtv.org>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
According with saa7130 public datasheet, saa7130 doesn't support
digital audio. This is also confirmed by experimental tests. So, it
doesn't make sense to let saa7134-alsa register for those chipsets.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
cpumask_and() only initializes nr_cpu_ids bits, so the (deprecated)
first_cpu() might find one of those uninitialized bits if nr_cpu_ids
is less than NR_CPUS (as it can be for CONFIG_CPUMASK_OFFSTACK).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Similar to the previous patch, by not clearing buddies we can select entities
past their run quota, which can increase latency. This means we have to clear
group buddies as well.
Do not use the group clear for pick_next_task(), otherwise that'll get O(n^2).
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It was noticed that a task could get re-elected past its run quota due to buddy
affinities. This could increase latency a little. Cure it by more aggresively
clearing buddy state.
We do so in two situations:
- when we force preempt
- when we select a buddy to run
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reinstate the weakening of the sync hint if set. This yields a more
symmetric usage of avg_overlap.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
