Mariusz Kozlowski reported lockdep's warning:
> =================================
> [ INFO: inconsistent lock state ]
> 2.6.23-rc2-mm1 #7
> ---------------------------------
> inconsistent {in-hardirq-W} -> {hardirq-on-W} usage.
> ifconfig/5492 [HC0[0]:SC0[0]:HE1:SE1] takes:
> (&tp->lock){+...}, at: [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too]
> {in-hardirq-W} state was registered at:
> [<c0138eeb>] __lock_acquire+0x949/0x11ac
> [<c01397e7>] lock_acquire+0x99/0xb2
> [<c0452ff3>] _spin_lock+0x35/0x42
> [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too]
> [<c0147a5d>] handle_IRQ_event+0x28/0x59
> [<c01493ca>] handle_level_irq+0xad/0x10b
> [<c0105a13>] do_IRQ+0x93/0xd0
> [<c010441e>] common_interrupt+0x2e/0x34
...
> other info that might help us debug this:
> 1 lock held by ifconfig/5492:
> #0: (rtnl_mutex){--..}, at: [<c0451778>] mutex_lock+0x1c/0x1f
>
> stack backtrace:
...
> [<c0452ff3>] _spin_lock+0x35/0x42
> [<de8706e0>] rtl8139_interrupt+0x27/0x46b [8139too]
> [<c01480fd>] free_irq+0x11b/0x146
> [<de871d59>] rtl8139_close+0x8a/0x14a [8139too]
> [<c03bde63>] dev_close+0x57/0x74
...
This shows that a driver's irq handler was running both in hard interrupt
and process contexts with irqs enabled. The latter was done during
free_irq() call and was possible only with CONFIG_DEBUG_SHIRQ enabled.
This was fixed by another patch.
But similar problem is possible with request_irq(): any locks taken from
irq handler could be vulnerable - especially with soft interrupts. This
patch fixes it by disabling local interrupts during handler's run. (It
seems, disabling softirqs should be enough, but it needs more checking
on possible races or other special cases).
Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we're going to run the handler from free_irq() then we must do it with
local irq's disabled. Otherwise lockdep complains that the handler is taking
irq-safe spinlocks in a non-irq-safe fashion.
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Level type interrupts are resent by the interrupt hardware when they are
still active at irq_enable().
Suppress the resend mechanism for interrupts marked as level.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 5a43a066b1: "genirq: Allow fasteoi
handler to retrigger disabled interrupts" was erroneously applied to
handle_level_irq(). This added the irq retrigger / resend functionality
to the level irq handler.
Revert the offending bits.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 0fc4969b86. It was
always meant to be temporary, but it's generating more useless noise
than anything else, and we probably should never have done it in the
generic kernel (only had the people involved test it on their own).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Marcin Slusarz reported a ne2k-pci "hung network interface" regression.
delayed disable relies on the ability to re-trigger the interrupt in the
case that a real interrupt happens after the software disable was set.
In this case we actually disable the interrupt on the hardware level
_after_ it occurred.
On enable_irq, we need to re-trigger the interrupt. On i386 this relies
on a hardware resend mechanism (send_IPI_self()).
Actually we only need the resend for edge type interrupts. Level type
interrupts come back once enable_irq() re-enables the interrupt line.
I assume that the interrupt in question is level triggered because it is
shared and above the legacy irqs 0-15:
17: 12 IO-APIC-fasteoi eth1, eth0
Looking into the IO_APIC code, the resend via send_IPI_self() happens
unconditionally. So the resend is done for level and edge interrupts.
This makes the problem more mysterious.
The code in question lib8390.c does
disable_irq();
fiddle_with_the_network_card_hardware()
enable_irq();
The fiddle_with_the_network_card_hardware() might cause interrupts,
which are cleared in the same code path again,
Marcin found that when he disables the irq line on the hardware level
(removing the delayed disable) the card is kept alive.
So the difference is that we can get a resend on enable_irq, when an
interrupt happens during the time, where we are in the disabled region.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we handle spurious IRQ activity based upon seeing a lot of
invalid interrupts, and we clear things back on the base of lots of valid
interrupts.
Unfortunately in some cases you get legitimate invalid interrupts caused by
timing asynchronicity between the PCI bus and the APIC bus when disabling
interrupts and pulling other tricks. In this case although the spurious
IRQs are not a problem our unhandled counters didn't clear and they act as
a slow running timebomb. (This is effectively what the serial port/tty
problem that was fixed by clearing counters when registering a handler
showed up)
It's easy enough to add a second parameter - time. This means that if we
see a regular stream of harmless spurious interrupts which are not harming
processing we don't go off and do something stupid like disable the IRQ
after a month of running. OTOH lockups and performance killers show up a
lot more than 10/second
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With irqpoll enabled, trying to test the IRQF_IRQPOLL flag in the
actions would cause a NULL pointer dereference if no action was
installed (for example, the driver might have been unloaded with
interrupts still pending).
So be a bit more careful about testing the flag by making sure to test
for that case.
(The actual _change_ is trivial, the patch is more than a one-liner
because I rewrote the testing to also be much more readable.
Original (discarded) bugfix by Bernhard Walle.
Cc: Bernhard Walle <bwalle@suse.de>
Tested-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On SN, only allow one bit to be set in the smp_affinty mask when
redirecting an interrupt. Currently setting multiple bits is allowed, but
only the first bit is used in determining the CPU to redirect to. This has
caused confusion among some customers.
[akpm@linux-foundation.org: fixes]
Signed-off-by: John Keller <jpk@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
irqpoll is broken on some architectures that don't use the IRQ 0 for the timer
interrupt like IA64. This patch adds a IRQF_IRQPOLL flag.
Each architecture is handled in a separate pach. As I left the irq == 0 as
condition, this should not break existing architectures that use timer_irq ==
0 and that I did't address with that patch (because I don't know).
This patch:
This patch adds a IRQF_IRQPOLL flag that the interrupt registration code could
use for the interrupt it wants to use for IRQ polling.
Because this must not be the timer interrupt, an additional flag was added
instead of re-using the IRQF_TIMER constant. Until all architectures will
have an IRQF_IRQPOLL interrupt, irq == 0 will stay as alternative as it should
not break anything.
Also, note_interrupt() is called on CPU-specific interrupts to be used as
interrupt source for IRQ polling.
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Grant Grundler <grundler@google.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We noticed a drop in n/w performance due to the irq_desc being cacheline
aligned rather than internode aligned. We see 50% of expected performance
when two e1000 nics local to two different nodes have consecutive irq
descriptors allocated, due to false sharing.
Note that this patch does away with cacheline padding for the UP case, as
it does not seem useful for UP configurations.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
An irqaction structure won't be added to an IRQ descriptor irqaction list if
it doesn't agree with other irqactions on the IRQF_PERCPU flag. Don't check
for this flag to change IRQ descriptor `status' for every irqaction added to
the list, Doing the check only for the first irqaction added is enough.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
setup_irq() releases a desc->lock before calling register_handler_proc(), so
the iteration over the IRQ action list is not protected.
(akpm: the check itself is still racy, but at least it probably won't oops
now).
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
set_irq_msi() currently connects an irq_desc to an msi_desc. The archs call
it at some point in their setup routine, and then the generic code sets up the
reverse mapping from the msi_desc back to the irq.
set_irq_msi() should do both connections, making it the one and only call
required to connect an irq with it's MSI desc and vice versa.
The arch code MUST call set_irq_msi(), and it must do so only once it's sure
it's not going to fail the irq allocation.
Given that there's no need for the arch to return the irq anymore, the return
value from the arch setup routine just becomes 0 for success and anything else
for failure.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
move_native_irqs tries to do the right thing when migrating irqs
by disabling them. However disabling them is a software logical
thing, not a hardware thing. This has always been a little flaky
and after Ingo's latest round of changes it is guaranteed to not
mask the apic.
So this patch fixes move_native_irq to directly call the mask and
unmask chip methods to guarantee that we mask the irq when we
are migrating it. We must do this as it is required by
all code that call into the path.
Since we don't know the masked status when IRQ_DISABLED is
set so we will not be able to restore it. The patch makes the code
just give up and trying again the next time this routing is called.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Never mask interrupts immediately upon request. Disabling interrupts in
high-performance codepaths is rare, and on the other hand this change could
recover lost edges (or even other types of lost interrupts) by conservatively
only masking interrupts after they happen. (NOTE: with this change the
highlevel irq-disable code still soft-disables this IRQ line - and if such an
interrupt happens then the IRQ flow handler keeps the IRQ masked.)
Mark i8529A controllers as 'never loses an edge'.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide funtions to:
- check, whether an interrupt can set the affinity
- pin the interrupt to a given cpu
Necessary for the ability to setup clocksources more flexible (e.g. use the
different HPET channels per CPU)
[akpm@osdl.org: alpha build fix]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a flag so we can prevent the irq balancing of an interrupt. Move the
bits, so we have room for more :)
Necessary for the ability to setup clocksources more flexible (e.g. use the
different HPET channels per CPU)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
