path: root/virt/kvm
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authorRobin Holt <>2009-04-02 16:59:45 -0700
committerLinus Torvalds <>2009-04-02 19:05:10 -0700
commite8c158bb313c1df421eab7dc4299cd39cbbf5895 (patch)
tree8a5f1d01e58d0e358b2b0c9407fc494912e83c27 /virt/kvm
parent41d577aa35aa0504fe28b76a948908bdb7fbec81 (diff)
Factor out #ifdefs from kernel/spinlock.c to LOCK_CONTENDED_FLAGS
SGI has observed that on large systems, interrupts are not serviced for a long period of time when waiting for a rwlock. The following patch series re-enables irqs while waiting for the lock, resembling the code which is already there for spinlocks. I only made the ia64 version, because the patch adds some overhead to the fast path. I assume there is currently no demand to have this for other architectures, because the systems are not so large. Of course, the possibility to implement raw_{read|write}_lock_flags for any architecture is still there. This patch: The new macro LOCK_CONTENDED_FLAGS expands to the correct implementation depending on the config options, so that IRQ's are re-enabled when possible, but they remain disabled if CONFIG_LOCKDEP is set. Signed-off-by: Petr Tesarik <> Signed-off-by: Robin Holt <> Cc: <> Cc: Ingo Molnar <> Cc: Peter Zijlstra <> Cc: "Luck, Tony" <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'virt/kvm')
0 files changed, 0 insertions, 0 deletions