diff options
| author | Yinghai Lu <yinghai@kernel.org> | 2014-05-13 11:39:34 -0400 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2014-06-04 14:18:34 +0200 |
| commit | ac2a55395eddccd6e3e39532df9869d61e97b2ee (patch) | |
| tree | 398113d67fd253cac9189fe566a5db9a401fe358 | |
| parent | d2cfd3105094f593bc1fbd0b042a7752ddf08691 (diff) | |
x86: irq: Get correct available vectors for cpu disable
check_irq_vectors_for_cpu_disable() can overestimate the number of
available interrupt vectors, so the check for cpu down succeeds, but
the actual cpu removal fails.
It iterates from FIRST_EXTERNAL_VECTOR to NR_VECTORS, which is wrong
because the systems vectors are not taken into account.
Limit the search to first_system_vector instead of NR_VECTORS.
The second indicator for vector availability the used_vectors bitmap
is not taken into account at all. So system vectors,
e.g. IA32_SYSCALL_VECTOR (0x80) and IRQ_MOVE_CLEANUP_VECTOR (0x20),
are accounted as available.
Add a check for the used_vectors bitmap and do not account vectors
which are marked there.
[ tglx: Simplified code. Rewrote changelog and code comments. ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Prarit Bhargava <prarit@redhat.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Elliott, Robert (Server Storage)" <Elliott@hp.com>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1400160305-17774-2-git-send-email-prarit@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | arch/x86/kernel/irq.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 283a76a9cc4..11ccfb0a63e 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -17,6 +17,7 @@ #include <asm/idle.h> #include <asm/mce.h> #include <asm/hw_irq.h> +#include <asm/desc.h> #define CREATE_TRACE_POINTS #include <asm/trace/irq_vectors.h> @@ -334,10 +335,17 @@ int check_irq_vectors_for_cpu_disable(void) for_each_online_cpu(cpu) { if (cpu == this_cpu) continue; - for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; - vector++) { - if (per_cpu(vector_irq, cpu)[vector] < 0) - count++; + /* + * We scan from FIRST_EXTERNAL_VECTOR to first system + * vector. If the vector is marked in the used vectors + * bitmap or an irq is assigned to it, we don't count + * it as available. + */ + for (vector = FIRST_EXTERNAL_VECTOR; + vector < first_system_vector; vector++) { + if (!test_bit(vector, used_vectors) && + per_cpu(vector_irq, cpu)[vector] < 0) + count++; } } |