diff options
| author | Matthew Wilcox <matthew@wil.cx> | 2008-11-20 22:09:33 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-11-20 22:17:40 +0100 |
| commit | 0ca4b6b00113b064c080d26d803d0d7c80fb5dc8 (patch) | |
| tree | 69e25f61bf252f2db0c0d01244555f90ad48aaf1 | |
| parent | SUNRPC: Fix a performance regression in the RPC authentication code (diff) | |
| download | linux-0ca4b6b00113b064c080d26d803d0d7c80fb5dc8.tar.xz linux-0ca4b6b00113b064c080d26d803d0d7c80fb5dc8.zip | |
x86: Fix interrupt leak due to migration
When we migrate an interrupt from one CPU to another, we set the
move_in_progress flag and clean up the vectors later once they're not
being used. If you're unlucky and call destroy_irq() before the vectors
become un-used, the move_in_progress flag is never cleared, which causes
the interrupt to become unusable.
This was discovered by Jesse Brandeburg for whom it manifested as an
MSI-X device refusing to use MSI-X mode when the driver was unloaded
and reloaded repeatedly.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/x86/kernel/io_apic.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c index 7a3f2028e2eb..c9513e1ff28d 100644 --- a/arch/x86/kernel/io_apic.c +++ b/arch/x86/kernel/io_apic.c @@ -1140,6 +1140,20 @@ static void __clear_irq_vector(int irq) cfg->vector = 0; cpus_clear(cfg->domain); + + if (likely(!cfg->move_in_progress)) + return; + cpus_and(mask, cfg->old_domain, cpu_online_map); + for_each_cpu_mask_nr(cpu, mask) { + for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; + vector++) { + if (per_cpu(vector_irq, cpu)[vector] != irq) + continue; + per_cpu(vector_irq, cpu)[vector] = -1; + break; + } + } + cfg->move_in_progress = 0; } void __setup_vector_irq(int cpu) |