Magnus Damm [Thu, 24 Apr 2008 12:47:15 +0000 (21:47 +0900)]
sh: no high level trigger on some sh3 cpus
The processor models sh7706, sh7707 and sh7709 don't support high
level trigger sense configuration. And the intc code looks like
crap these days so what's the difference.
Signed-off-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Magnus Damm [Thu, 24 Apr 2008 12:41:12 +0000 (21:41 +0900)]
sh: clean up sh7710 and sh7720 intc tables
Clean up the intc tables by removing unneeded #ifdefs. The vector
list is what selects which interrupt sources that should be added,
having unsupported bitfields listed is ok as long as the vector
is excluded from the list.
Signed-off-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Magnus Damm [Thu, 24 Apr 2008 12:36:34 +0000 (21:36 +0900)]
sh: add interrupt ack code to sh3
This patch adds interrupt acknowledge code for external interrupt
sources on sh3 processors. Only really required for edge triggered
interrupts, but we ack regardless of sense configuration.
Signed-off-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Magnus Damm [Thu, 24 Apr 2008 12:30:09 +0000 (21:30 +0900)]
sh: unify external irq pin code for sh3
This patch unifies the sh3 external irq pin code. It buys us some
savings with reduced code redundancy, but the main feature with
this change is irq sense selection support for all sh3 processors.
Signed-off-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Linus Torvalds [Wed, 7 May 2008 00:09:27 +0000 (17:09 -0700)]
Revert "uml: fix gcc problem"
This reverts commit 22eecde2f9034764a3fd095eecfa3adfb8ec9a98. Uli
reports that it breaks UML on x86-64 with the Fedora 8 gcc (gcc 4.1.2),
causing a crash on startup. See
OGAWA Hirofumi [Tue, 6 May 2008 19:02:53 +0000 (04:02 +0900)]
Fix bogus warning in sysdev_driver_register()
if ((drv->entry.next != drv->entry.prev) ||
(drv->entry.next != NULL)) {
warns list_empty(&drv->entry).
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Greg KH <gregkh@suse.de> Cc: Len Brown <lenb@kernel.org>
[ Version 2 totally redone based on suggestions from Linus & Greg ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Tue, 6 May 2008 20:13:37 +0000 (13:13 -0700)]
VFS: fix unused variable warning
Commit 33dcdac2df54e66c447ae03f58c95c7251aa5649 ("kill ->put_inode")
removed the final use of i_op->put_inode, but left the now totally
unused "op" variable in iput().
Hugh Dickins [Tue, 6 May 2008 19:49:23 +0000 (20:49 +0100)]
x86: fix PAE pmd_bad bootup warning
Fix warning from pmd_bad() at bootup on a HIGHMEM64G HIGHPTE x86_32.
That came from 9fc34113f6880b215cbea4e7017fc818700384c2 x86: debug pmd_bad();
but we understand now that the typecasting was wrong for PAE in the previous
version: pagetable pages above 4GB looked bad and stopped Arjan from booting.
And revert that cded932b75ab0a5f9181ee3da34a0a488d1a14fd x86: fix pmd_bad
and pud_bad to support huge pages. It was the wrong way round: we shouldn't
weaken every pmd_bad and pud_bad check to let huge pages slip through - in
part they check that we _don't_ have a huge page where it's not expected.
Put the x86 pmd_bad() and pud_bad() definitions back to what they have long
been: they can be improved (x86_32 should use PTE_MASK, to stop PAE thinking
junk in the upper word is good; and x86_64 should follow x86_32's stricter
comparison, to stop thinking any subset of required bits is good); but that
should be a later patch.
Fix Hans' good observation that follow_page() will never find pmd_huge()
because that would have already failed the pmd_bad test: test pmd_huge in
between the pmd_none and pmd_bad tests. Tighten x86's pmd_huge() check?
No, once it's a hugepage entry, it can get quite far from a good pmd: for
example, PROT_NONE leaves it with only ACCESSED of the KERN_PGTABLE bits.
However... though follow_page() contains this and another test for huge
pages, so it's nice to keep it working on them, where does it actually get
called on a huge page? get_user_pages() checks is_vm_hugetlb_page(vma) to
to call alternative hugetlb processing, as does unmap_vmas() and others.
Signed-off-by: Hugh Dickins <hugh@veritas.com> Earlier-version-tested-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jeff Chua <jeff.chua.linux@gmail.com> Cc: Hans Rosenfeld <hans.rosenfeld@amd.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Al Viro [Tue, 6 May 2008 17:58:34 +0000 (13:58 -0400)]
[PATCH] fix SMP ordering hole in fcntl_setlk()
fcntl_setlk()/close() race prevention has a subtle hole - we need to
make sure that if we *do* have an fcntl/close race on SMP box, the
access to descriptor table and inode->i_flock won't get reordered.
As it is, we get STORE inode->i_flock, LOAD descriptor table entry vs.
STORE descriptor table entry, LOAD inode->i_flock with not a single
lock in common on both sides. We do have BKL around the first STORE,
but check in locks_remove_posix() is outside of BKL and for a good
reason - we don't want BKL on common path of close(2).
Solution is to hold ->file_lock around fcheck() in there; that orders
us wrt removal from descriptor table that preceded locks_remove_posix()
on close path and we either come first (in which case eviction will be
handled by the close side) or we'll see the effect of close and do
eviction ourselves. Note that even though it's read-only access,
we do need ->file_lock here - rcu_read_lock() won't be enough to
order the things.
And with that last patch to affs killing the last put_inode instance we
can finally, after many years of transition kill this racy and awkward
interface.
(It's kinda funny that even the description in
Documentation/filesystems/vfs.txt was entirely wrong..)
Also remove a very misleading comment above the defintion of
struct super_operations.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Roman Zippel [Tue, 29 Apr 2008 15:02:20 +0000 (17:02 +0200)]
[PATCH] fix reservation discarding in affs
- remove affs_put_inode, so preallocations aren't discared unnecessarily
often.
- remove affs_drop_inode, it's called with a spinlock held, so it can't
use a mutex.
- make i_opencnt atomic
- avoid direct b_count manipulations
- a few allocation failure fixes, so that these are more gracefully
handled now. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Linus Torvalds [Tue, 6 May 2008 16:17:03 +0000 (09:17 -0700)]
Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: (27 commits)
pata_atiixp: Don't disable
sata_inic162x: update intro comment, up the version and drop EXPERIMENTAL
sata_inic162x: add cardbus support
sata_inic162x: kill now unused SFF related stuff
sata_inic162x: use IDMA for ATAPI commands
sata_inic162x: use IDMA for non DMA ATA commands
sata_inic162x: kill now unused bmdma related stuff
sata_inic162x: use IDMA for ATA_PROT_DMA
sata_inic162x: update TF read handling
sata_inic162x: add / update constants
sata_inic162x: misc clean ups
sata_mv use hweight16() for bit counting (V2)
sata_mv NCQ-EH for FIS-based switching
sata_mv delayed eh handling
libata: export ata_eh_analyze_ncq_error
sata_mv new mv_port_intr function
sata_mv fix mv_host_intr bug for hc_irq_cause
sata_mv NCQ and SError fixes for mv_err_intr
sata_mv rearrange mv_config_fbs
sata_mv errata workaround for sata25 part 1
...
Alan Cox [Fri, 2 May 2008 22:13:39 +0000 (15:13 -0700)]
pata_atiixp: Don't disable
A couple of distributions (Fedora, Ubuntu) were having weird problems with the
ATI IXP series PATA controllers being reported as simplex. At the heart of
the problem is that both distros ignored the recommendations to load pata_acpi
and ata_generic *AFTER* specific host drivers.
The underlying cause however is that if you D3 and then D0 an ATI IXP it
helpfully throws away some configuration and won't let you rewrite it.
Add checks to ata_generic and pata_acpi to pin ATIIXP devices. Possibly the
real answer here is to quirk them and pin them, but right now we can't do that
before they've been pcim_enable()'d by a driver.
I'm indebted to David Gero for this. His bug report not only reported the
problem but identified the cause correctly and he had tested the right values
to prove what was going on
[If you backport this for 2.6.24 you will need to pull in the 2.6.25
removal of the bogus WARN_ON() in pcim_enagle]
Signed-off-by: Alan Cox <alan@redhat.com> Tested-by: David Gero <davidg@havidave.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
sata_inic162x now doesn't use any SFF features. Remove all SFF
related stuff.
* Mask unsolicited ATA interrupts. This removes our primary source of
spurious interrupts and spurious interrupt handling can be tightened
up. There's no need to clear ATA interrupts by reading status
register either.
* Don't dance with IDMA_CTL_ATA_NIEN and simplify accesses to
IDMA_CTL.
* Inherit from sata_port_ops instead of ata_sff_port_ops.
* Don't initialize or use ioaddr. There's no need to map BAR0-4
anymore.
Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Use IDMA for ATAPI commands. Write and some misc commands time out
when executed using ATAPI_PROT_DMA but ATAPI_PROT_PIO works fine. As
PIO is driven by DMA too, it doesn't make any noticeable difference
for native SATA devices. inic_check_atapi_dma() is implemented to
force PIO for those ATAPI commands.
After this change, sata_inic162x issues all commands using IDMA.
Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Use IDMA for PIO and non-data commands. This allows sata_inic162x to
safely drive LBA48 devices. Kill inic_dev_config() which contains
code to reject LBA48 devices.
With this change, status checking in inic_qc_issue() to avoid hard
lock up after hotplug can go away too.
Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
The modified driver on initio site has enough clue on how to use IDMA.
Use IDMA for ATA_PROT_DMA.
* LBA48 now works as long as it uses DMA (LBA48 devices still aren't
allowed as it can destroy data if PIO is used for any reason).
* No need to mask IRQs for read DMAs as IDMA_DONE is properly raised
after transfer to memory is actually completed. There will be some
spurious interrupts but host_intr will handle it correctly and
manipulating port IRQ mask interacts badly with the other port for
some reason, so command type dependent port IRQ masking is not used
anymore.
Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Tejun Heo [Thu, 1 May 2008 14:55:58 +0000 (23:55 +0900)]
sata_inic162x: update TF read handling
inic162x can't reliably read back TF or at least we don't know how to
do it yet. The only values which seem reliable are status and error.
This patch updates access to TF.
* implement inic_tf_read() which reads the TF area in mmio area
* implement custom inic_qc_fill_rtf() which only returns true if
status indicates device error. it'll be returning bogus addresses
for device errors but it'll be able to report why it failed at
least.
* implement custom inic_check_ready() and use ata_wait_after_reset()
instead of the SFF version.
* use inic_tf_read() for classification.
This is not perfect but it fixes hotplug detection failure and at
least makes the driver report 0's instead of random garbages while
reporting valid status and error for device errors.
Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mark Lord [Fri, 2 May 2008 18:02:28 +0000 (14:02 -0400)]
sata_mv use hweight16() for bit counting (V2)
Some tidying as suggested by Grant Grundler.
Nuke local bit-counting function from sata_mv in favour of using hweight16().
Also add a short explanation for the 15msec timeout used when waiting for empty/idle.
Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mark Lord [Fri, 2 May 2008 06:16:20 +0000 (02:16 -0400)]
sata_mv NCQ-EH for FIS-based switching
Convert sata_mv's EH for FIS-based switching (FBS) over to the
sequence recommended by Marvell. This enables us to catch/analyze
multiple failed links on a port-multiplier when using NCQ.
To do this, we clear the ERR_DEV bit in the EDMA Halt-Conditions register,
so that the EDMA engine doesn't self-disable on the first NCQ error.
Our EH code sets the MV_PP_FLAG_DELAYED_EH flag to prevent new commands
being queued while we await completion of all outstanding NCQ commands
on all links of the failed PM.
The SATA Test Control register tells us which links have failed,
so we must only wait for any other active links to finish up
before we stop the EDMA and run the .error_handler afterward.
The patch also includes skeleton code for handling of non-NCQ FBS operation.
This is more for documentation purposes right now, as that mode is not yet
enabled in sata_mv.
Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mark Lord [Fri, 2 May 2008 06:15:37 +0000 (02:15 -0400)]
sata_mv delayed eh handling
Introduce a new "delayed error handling" mechanism in sata_mv,
to enable us to eventually deal with multiple simultaneous NCQ
failures on a single host link when a PM is present.
This involves a port flag (MV_PP_FLAG_DELAYED_EH) to prevent new
commands being queued, and a pmp bitmap to indicate which pmp links
had NCQ errors.
The new mv_pmp_error_handler() uses those values to invoke
ata_eh_analyze_ncq_error() on each failed link, prior to freezing
the port and passing control to sata_pmp_error_handler().
This is based upon a strategy suggested by Tejun.
For now, we just implement the delayed mechanism.
The next patch in this series will add the multiple-NCQ EH code
to take advantage of it.
Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mark Lord [Fri, 2 May 2008 06:12:34 +0000 (02:12 -0400)]
sata_mv NCQ and SError fixes for mv_err_intr
Sigh. Undo some earlier changes to mv_port_intr(),
so that we now read/clear SError again in all cases.
Arrange the top of the function to be as close as possible
to what we need for a later update (in this series) for ERR_DEV handling.
Fix things so that libata-eh can attempt a READ_LOG_EXT_10H
in response to a failed NCQ command, by just doing a local
mv_eh_freeze() rather than ata_port_freeze().
This will now fully handle NCQ errors much of the time,
but more fixes are needed for FBS/PMP, and for certain chip errata.
Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mark Lord [Fri, 2 May 2008 06:10:02 +0000 (02:10 -0400)]
sata_mv new mv_qc_defer method
The EDMA engine cannot tolerate a mix of NCQ/non-NCQ commands,
and cannot be used for PIO at all. So we need to prevent libata
from trying to feed us such mixtures.
Introduce mv_qc_defer() for this purpose, and use it for all chip versions.
Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mark Lord [Fri, 2 May 2008 06:09:14 +0000 (02:09 -0400)]
sata_mv wait for empty+idle
When performing EH, it is recommended to wait for the EDMA engine
to empty out requests-in-progress before disabling EDMA.
Introduce code to poll the EDMA_STATUS register for idle/empty bits
before disabling EDMA. For non-EH operation, this will normally exit
without delay, other than the register read.
A later series of patches may focus on eliminating this and various
other register reads (when possible) throughout the driver,
but for now we're focussing on solid reliablity.
Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mark Lord [Fri, 2 May 2008 06:08:32 +0000 (02:08 -0400)]
sata_mv pci features
Some of the GenIIe EDMA optimizations should not be used
for non-PCI (SOC) devices, and nor for certain configurations
of conventional PCI (non PCI-X, PCIe) buses.
Logic taken/simplified from that in the Marvell proprietary driver.
Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mark Lord [Fri, 2 May 2008 06:07:51 +0000 (02:07 -0400)]
sata_mv more cosmetic changes
More cosmetic changes; no code changes.
-- try and improve consistency of naming.
-- add missing _OFS to tails of register offset definitions.
-- rename mv_setup_ifctl() to mv_setup_ifcfg(), since that's what it really does.
-- remove/move some dead comments
Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Tejun Heo [Thu, 1 May 2008 01:03:08 +0000 (10:03 +0900)]
ata_piix: verify SIDPR access before enabling it
On certain configurations (certain macbooks), even though all the
conditions for SIDPR access described in the datasheet are met,
actually reading those registers just returns 0 and have no effect on
write. Verify SIDPR is actually working before enabling it.
This is reported by Ryan Roth in bz#10512.
Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Ryan Roth <ryan.roth@ch2m.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Tejun Heo [Thu, 1 May 2008 14:41:41 +0000 (23:41 +0900)]
libata: improve post-reset device ready test
Some controllers (jmb and inic162x) use 0x77 and 0x7f to indicate that
the device isn't ready yet. It looks like they use 0xff if device
presence is detected but connection isn't established. 0x77 or 0x7f
after connection is established and use the value from signature FIS
after receiving it.
This patch implements ata_check_ready(), which takes TF status value
and determines whether the port is ready or not considering the above
and other conditions, and use it in @check_ready() functions. This is
safe as both 0x77 and 0x7f aren't valid ready status value even though
they have BSY bit cleared.
This fixes hot plug detection failures which can be triggered with
certain drives if they aren't already spun up when the data connector
is hot plugged.
Tested on sil, sil24, ahci (jmb/ich), piix and inic162x combined with
eight drives from all major vendors.
Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
net_cls_act: act_simple dont ignore realloc code
iwlwifi: make IWLWIFI a tristate
Revert "atm: Do not free already unregistered net device."
dccp: return -EINVAL on invalid feature length
irda: fix !PNP support for drivers/net/irda/smsc-ircc2.c
irda: fix !PNP support in drivers/net/irda/nsc-ircc.c
net_cls_act: Make act_simple use of netlink policy.
ip: Use inline function dst_metric() instead of direct access to dst->metric[]
ip: Make use of the inline function dst_metric_locked()
atm: Bad locking on br2684_devs modifications.
atm: Do not free already unregistered net device.
mac80211: Do not free net device after it is unregistered.
bridge: Consolidate error paths in br_add_bridge().
bridge: Net device leak in br_add_bridge().
niu: Fix probing regression for maramba on-board chips.
lapbeth: Release ->ethdev when unregistering device.
xfrm: convert empty xfrm_audit_* macros to functions
net: Fix useless comment reference loop.
sch_htb: remove from event queue in htb_parent_to_leaf()
Adrian Bunk [Tue, 6 May 2008 07:04:47 +0000 (00:04 -0700)]
iwlwifi: make IWLWIFI a tristate
IWLWIFI should be a tristate so that if IWLCORE and/or IWL3945 are m
and none of them is y kbuild doesn't create an empty
drivers/net/wireless/built-in.o
This patch also removes the pointless "default n".
Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Tue, 6 May 2008 00:31:41 +0000 (17:31 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
mlx4_core: Support creation of FMRs with pages smaller than 4K
IB/ehca: Fix function return types
RDMA/cxgb3: Bump up the MPA connection setup timeout.
RDMA/cxgb3: Silently ignore close reply after abort.
RDMA/cxgb3: QP flush fixes
IB/ipoib: Fix transmit queue stalling forever
IB/mlx4: Fix off-by-one errors in calls to mlx4_ib_free_cq_buf()
Linus Torvalds [Tue, 6 May 2008 00:31:14 +0000 (17:31 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-fixes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-fixes:
sched: default to n for GROUP_SCHED and FAIR_GROUP_SCHED
sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
sched, x86: add HAVE_UNSTABLE_SCHED_CLOCK
sched: fix cpu clock
sched: fair-group: fix a Div0 error of the fair group scheduler
sched: fix missing locking in sched_domains code
sched: make clock sync tunable by architecture code
sched: fix debugging
sched: fix sched_info_switch not being called according to documentation
sched: fix hrtick_start_fair and CPU-Hotplug
sched: fix SCHED_FAIR wake-idle logic error
sched: fix RT task-wakeup logic
sched: add statics, don't return void expressions
sched: add debug checks to idle functions
sched: remove old sched doc
sched: make rt_sched_class, idle_sched_class static
sched: optimize calc_delta_mine()
sched: fix normalized sleeper
Oren Duer [Mon, 5 May 2008 22:56:52 +0000 (15:56 -0700)]
mlx4_core: Support creation of FMRs with pages smaller than 4K
Don't hard code a test against a minimum page shift of 12, since the
device may support smaller pages. Test against the actual smallest
page size from the device capabilities.
Signed-off-by: Oren Duer <oren@mellanox.co.il> Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Roland Dreier <rolandd@cisco.com>
Commit 06916639e2fed9ee475efef2747a1b7429f8fe76 ("driver-core: add
dev_name() to help transition away from using bus_id") added a static
inline dev_name() and used it in dev_printk.
Unfortunately, drivers/edac/edac_core.h defines a macro called
dev_name(). Rename the latter.
David Miller pointed it out that nothing in cpu_clock() sets
prev_cpu_time. This caused __sync_cpu_clock() to be called
all the time - against the intention of this code.
The result was that in practice we hit a global spinlock every
time cpu_clock() is called - which - even though cpu_clock()
is used for tracing and debugging, is suboptimal.
While at it, also:
- move the irq disabling to the outest layer,
this should make cpu_clock() warp-free when called with irqs
enabled.
- use long long instead of cycles_t - for platforms where cycles_t
is 32-bit.
Reported-by: David Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
When the echoed value was less than the number of processores, the result of the
sentence "shares/nr_cpu_ids" was 0, and then the system called div64() to divide
the result, the Div0 error occured.
It is unnecessary that the shares value is divided by nr_cpu_ids, I think.
Because in the function __update_group_shares_cpu() and init_tg_cfs_entry(),
the shares value isn't divided by nr_cpu_ids when setting shares of the sched
entity.
This patch fixes this bug. And echoing ULONG_MAX value into cpu.shares also
causes Div0 error, so we set a macro MAX_SHARES to limit the max value of
shares.
Concurrent calls to detach_destroy_domains and arch_init_sched_domains
were prevented by the old scheduler subsystem cpu hotplug mutex. When
this got converted to get_online_cpus() the locking got broken.
Unlike before now several processes can concurrently enter the critical
sections that were protected by the old lock.
So use the already present doms_cur_mutex to protect these sections again.
Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Peter Zijlstra [Tue, 29 Apr 2008 08:02:46 +0000 (10:02 +0200)]
sched: fix hrtick_start_fair and CPU-Hotplug
Gautham R Shenoy reported:
> While running the usual CPU-Hotplug stress tests on linux-2.6.25,
> I noticed the following in the console logs.
>
> This is a wee bit difficult to reproduce. In the past 10 runs I hit this
> only once.
>
> ------------[ cut here ]------------
>
> WARNING: at kernel/sched.c:962 hrtick+0x2e/0x65()
>
> Just wondering if we are doing a good job at handling the cancellation
> of any per-cpu scheduler timers during CPU-Hotplug.
This looks like its indeed not cancelled at all and migrates the it to
another cpu. Fix it via a proper hotplug notifier mechanism.
Reported-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
We currently use an optimization to skip the overhead of wake-idle
processing if more than one task is assigned to a run-queue. The
assumption is that the system must already be load-balanced or we
wouldnt be overloaded to begin with.
The problem is that we are looking at rq->nr_running, which may include
RT tasks in addition to CFS tasks. Since the presence of RT tasks
really has no bearing on the balance status of CFS tasks, this throws
the calculation off.
This patch changes the logic to only consider the number of CFS tasks
when making the decision to optimze the wake-idle.
projects / linux-2.6 / log