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  1. 04 6月, 2009 2 次提交
    • A
      x86: fix panic with interrupts off (needed for MCE) · 4ef702c1
      由 Andi Kleen 提交于 
      For some time each panic() called with interrupts disabled
triggered the !irqs_disabled() WARN_ON in smp_call_function(),
producing ugly backtraces and confusing users.

This is a common situation with machine checks for example which
tend to call panic with interrupts disabled, but will also hit
in other situations e.g. panic during early boot.  In fact it
means that panic cannot be called in many circumstances, which
would be bad.

This all started with the new fancy queued smp_call_function,
which is then used by the shutdown path to shut down the other
CPUs.

On closer examination it turned out that the fancy RCU
smp_call_function() does lots of things not suitable in a panic
situation anyways, like allocating memory and relying on complex
system state.

I originally tried to patch this over by checking for panic
there, but it was quite complicated and the original patch
was also not very popular.  This also didn't fix some of the
underlying complexity problems.

The new code in post 2.6.29 tries to patch around this by
checking for oops_in_progress, but that is not enough to make
this fully safe and I don't think that's a real solution
because panic has to be reliable.

So instead use an own vector to reboot.  This makes the reboot
code extremly straight forward, which is definitely a big plus
in a panic situation where it is important to avoid relying on
too much kernel state.  The new simple code is also safe to be
called from interupts off region because it is very very simple.

There can be situations where it is important that panic
is reliable.  For example on a fatal machine check the panic
is needed to get the system up again and running as quickly
as possible.  So it's important that panic is reliable and
all function it calls simple.

This is why I came up with this simple vector scheme.
It's very hard to beat in simplicity.  Vectors are not
particularly precious anymore since all big systems are
using per CPU vectors.

Another possibility would have been to use an NMI similar
to kdump, but there is still the problem that NMIs don't
work reliably on some systems due to BIOS issues.  NMIs
would have been able to stop CPUs running with interrupts
off too.  In the sake of universal reliability I opted for
using a non NMI vector for now.

I put the reboot vector into the highest priority bucket of
the APIC vectors and moved the 64bit UV_BAU message down
instead into the next lower priority.

[ Impact: bug fix, fixes an old regression ]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      4ef702c1
    • A
      x86, mce: implement bootstrapping for machine check wakeups · ccc3c319
      由 Andi Kleen 提交于 
      Machine checks support waking up the mcelog daemon quickly.

The original wake up code for this was pretty ugly, relying on
a idle notifier and a special process flag. The reason it did
it this way is that the machine check handler is not subject
to normal interrupt locking rules so it's not safe
to call wake_up().  Instead it set a process flag
and then either did the wakeup in the syscall return
or in the idle notifier.

This patch adds a new "bootstraping" method as replacement.

The idea is that the handler checks if it's in a state where
it is unsafe to call wake_up(). If it's safe it calls it directly.
When it's not safe -- that is it interrupted in a critical
section with interrupts disables -- it uses a new "self IPI" to trigger
an IPI to its own CPU. This can be done safely because IPI
triggers are atomic with some care. The IPI is raised
once the interrupts are reenabled and can then safely call
wake_up().

When APICs are disabled the event is just queued and will be picked up
eventually by the next polling timer. I think that's a reasonable
compromise, since it should only happen quite rarely.

Contains fixes from Ying Huang.

[ solve conflict on irqinit, make it work on 32bit (entry_arch.h) - HS ]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      ccc3c319
  3. 16 4月, 2009 1 次提交
    • Y
      x86: use used_vectors in init_IRQ() · 77857dc0
      由 Yinghai Lu 提交于 
      Impact: fix crash with many devices

I found this crash:

[  552.616646] general protection fault: 0403 [#1] SMP
[  552.620013] last sysfs file:
/sys/devices/pci0000:00/0000:00:02.0/usb1/1-1/1-1:1.0/host13/target13:0:0/13:0:0:0/block/sr0/size
[  552.620013] CPU 0
[  552.620013] Modules linked in:
[  552.620013] Pid: 0, comm: swapper Not tainted 2.6.30-rc1-tip-01931-g8fcafd8-dirty #28 Sun Fire X4440
[  552.620013] RIP: 0010:[<ffffffff8023bada>]  [<ffffffff8023bada>] default_idle+0x7d/0xda
[  552.620013] RSP: 0018:ffffffff81345e68  EFLAGS: 00010246
[  552.620013] RAX: 0000000000000000 RBX: ffffffff8133d870 RCX: ffffc20000000000
[  552.620013] RDX: 00000000001d0620 RSI: ffffffff8023bad8 RDI: ffffffff802a3169
[  552.620013] RBP: ffffffff81345e98 R08: 0000000000000000 R09: ffffffff812244a0
[  552.620013] R10: ffffffff81345dc8 R11: 7ebe1b6fa0bcac50 R12: 4ec4ec4ec4ec4ec5
[  552.620013] R13: ffffffff813a54d0 R14: ffffffff813a7a40 R15: 0000000000000000
[  552.620013] FS:  00000000006d1880(0000) GS:ffffc20000000000(0000) knlGS:0000000000000000
[  552.620013] CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
[  552.620013] CR2: 00007fec9d936a50 CR3: 000000007d1a9000 CR4: 00000000000006e0
[  552.620013] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  552.620013] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  552.620013] Process swapper (pid: 0, threadinfo ffffffff81344000,task ffffffff812244a0)
[  552.620013] Stack:
[  552.620013]  0000000000000000 ffffc20000000000 00000000001d0620 7ebe1b6fa0bcac50
[  552.620013]  ffffffff8133d870 4ec4ec4ec4ec4ec5 ffffffff81345ec8 ffffffff8023bd84
[  552.620013]  4ec4ec4ec4ec4ec5 ffffffff813a54d0 7ebe1b6fa0bcac50 ffffffff8133d870
[  552.620013] Call Trace:
[  552.620013]  [<ffffffff8023bd84>] c1e_idle+0x109/0x124
[  552.620013]  [<ffffffff8023314b>] cpu_idle+0xb8/0x101
[  552.620013]  [<ffffffff80c16d6a>] rest_init+0x7e/0x94
[  552.620013]  [<ffffffff81357efc>] start_kernel+0x3dc/0x3fd
[  552.620013]  [<ffffffff813572a9>] x86_64_start_reservations+0xb9/0xd4
[  552.620013]  [<ffffffff813573b2>] x86_64_start_kernel+0xee/0x109
[  552.620013] Code: 48 8b 04 25 f8 b4 00 00 83 a0 3c e0 ff ff fb 0f ae f0 65 48 8b 04 25 f8 b4 00 00 f6 80 38 e0 ff ff 08 75 09 e8 71 76 06 00 fb f4 <eb> 06 e8 68 76 06 00 fb 65 48 8b 04 25 f8 b4 00 00 83 88 3c e0
[  552.620013] RIP  [<ffffffff8023bada>] default_idle+0x7d/0xda
[  552.620013]  RSP <ffffffff81345e68>
[  552.828646] ---[ end trace 4cbfc5c01382af7f ]---

Joerg Roedel said
	"The 0403 error code means that there was an external interrupt with vector
	0x80. Yinghai, my theory is that the kernel on this machine has no 32bit
	emulation compiled in, right? In this case the selector points to a zero entry
	which may cause the #gpf right after the hlt.
	But I have no idea where the external int 0x80 comes from"

it turns out that we could use 0x80 for external device on 64-bit
when 32-bit emulation is disabled.

But we forgot to set the gate for it.

try to set gate for it by checking used_vectors.

Also move apic_intr_init() early to avoid setting
that gate two times.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <49E62DFD.6010904@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      77857dc0
  5. 10 4月, 2009 14 次提交
  7. 07 4月, 2009 1 次提交
  9. 30 3月, 2009 1 次提交
  11. 05 3月, 2009 1 次提交
  13. 23 2月, 2009 1 次提交
    • I
      x86: refactor x86_quirks support · 8e6dafd6
      由 Ingo Molnar 提交于 
      Impact: cleanup

Make x86_quirks support more transparent. The highlevel
methods are now named:

  extern void x86_quirk_pre_intr_init(void);
  extern void x86_quirk_intr_init(void);

  extern void x86_quirk_trap_init(void);

  extern void x86_quirk_pre_time_init(void);
  extern void x86_quirk_time_init(void);

This makes it clear that if some platform extension has to
do something here that it is considered ... weird, and is
discouraged.

Also remove arch_hooks.h and move it into setup.h (and other
header files where appropriate).
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      8e6dafd6
  15. 02 2月, 2009 1 次提交
  17. 01 2月, 2009 1 次提交
  19. 27 1月, 2009 1 次提交
  21. 21 1月, 2009 1 次提交
    • T
      x86: make x86_32 use tlb_64.c · 02cf94c3
      由 Tejun Heo 提交于 
      Impact: less contention when issuing invalidate IPI, cleanup

Make x86_32 use the same tlb code as 64bit.  The 64bit code uses
multiple IPI vectors for tlb shootdown to reduce contention.  This
patch makes x86_32 allocate the same 8 IPIs as x86_64 and share the
code paths.

Note that the usage of asmlinkage is inconsistent for x86_32 and 64
and calls for further cleanup.  This has been noted with a FIXME
comment in tlb_64.c.
Signed-off-by: NTejun Heo <tj@kernel.org>
      02cf94c3
  23. 05 1月, 2009 1 次提交
  25. 24 12月, 2008 1 次提交
    • Y
      x86: fix lguest used_vectors breakage, -v2 · b77b881f
      由 Yinghai Lu 提交于 
      Impact: fix lguest, clean up

32-bit lguest used used_vectors to record vectors, but that model of
allocating vectors changed and got broken, after we changed vector
allocation to a per_cpu array.

Try enable that for 64bit, and the array is used for all vectors that
are not managed by vector_irq per_cpu array.

Also kill system_vectors[], that is now a duplication of the
used_vectors bitmap.

[ merged in cpus4096 due to io_apic.c cpumask changes. ]
[ -v2, fix build failure ]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      b77b881f
  27. 08 12月, 2008 3 次提交
    • I
      performance counters: x86 support · 241771ef
      由 Ingo Molnar 提交于 
      Implement performance counters for x86 Intel CPUs.

It's simplified right now: the PERFMON CPU feature is assumed,
which is available in Core2 and later Intel CPUs.

The design is flexible to be extended to more CPU types as well.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      241771ef
    • Y
      x86: use NR_IRQS_LEGACY · 99d093d1
      由 Yinghai Lu 提交于 
      Impact: cleanup

Introduce NR_IRQS_LEGACY instead of hard coded number.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      99d093d1
    • Y
      sparse irq_desc[] array: core kernel and x86 changes · 0b8f1efa
      由 Yinghai Lu 提交于 
      Impact: new feature

Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with
NR_CPUS set to large values. The goal is to be able to scale up to much
larger NR_IRQS value without impacting the (important) common case.

To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of
irq_desc pointers.

When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc,
this also makes the IRQ descriptors NUMA-local (to the site that calls
request_irq()).

This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now
uses desc->chip_data for x86 to store irq_cfg.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      0b8f1efa
  29. 12 11月, 2008 1 次提交
  31. 16 10月, 2008 5 次提交
  33. 11 8月, 2008 1 次提交
  35. 24 5月, 2008 3 次提交