x86/irq: mark NUMA_MIGRATE_IRQ_DESC broken

It causes crash on system with lots of cards with MSI-X
when irq_balancer enabled...

The patches fixing it were both complex and fragile, according
to Eric they were also doing quite dangerous things to the
hardware.

Instead we now have patches that solve this problem via static
NUMA node mappings - not dynamic allocation and balancing.

The patches are much simpler than this method but are still too
large outside of the merge window, so we mark the dynamic balancer
as broken for now, and queue up the new approach for v2.6.31.

[ Impact: deactivate broken kernel feature ]

Reported-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <49E68C41.4020801@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index bc25b9f5e4cd27583ba2a079850b55858546ef43..b1d2be7d91a024e37e1962e0c5e4503e11bb83ab 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -277,6 +277,7 @@ config SPARSE_IRQ
 config NUMA_MIGRATE_IRQ_DESC
        bool "Move irq desc when changing irq smp_affinity"
        depends on SPARSE_IRQ && NUMA
+       depends on BROKEN
        default n
        ---help---
          This enables moving irq_desc to cpu/node that irq will use handled.