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| author | Sagi Grimberg <sagig@mellanox.co.il> | 2012-10-08 16:29:24 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-02-28 06:32:24 -0800 |
| commit | ed5ac19078a65a66008f9bef0037b56828349b5b (patch) | |
| tree | 89ae3c7b9ac90ca25ce93bc1b5e7caf4ed02d7de /include | |
| parent | 0eec39b02834d2af586ec6ebe84117273995021c (diff) | |
| download | lwn-ed5ac19078a65a66008f9bef0037b56828349b5b.tar.gz lwn-ed5ac19078a65a66008f9bef0037b56828349b5b.zip | |
mm: mmu_notifier: have mmu_notifiers use a global SRCU so they may safely schedule
commit 21a92735f660eaecf69a6f2e777f18463760ec32 upstream.
With an RCU based mmu_notifier implementation, any callout to
mmu_notifier_invalidate_range_{start,end}() or
mmu_notifier_invalidate_page() would not be allowed to call schedule()
as that could potentially allow a modification to the mmu_notifier
structure while it is currently being used.
Since srcu allocs 4 machine words per instance per cpu, we may end up
with memory exhaustion if we use srcu per mm. So all mms share a global
srcu. Note that during large mmu_notifier activity exit & unregister
paths might hang for longer periods, but it is tolerable for current
mmu_notifier clients.
Signed-off-by: Sagi Grimberg <sagig@mellanox.co.il>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Haggai Eran <haggaie@mellanox.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mmu_notifier.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 1d1b1e13f79f..ee2baf034fc4 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -4,6 +4,7 @@ #include <linux/list.h> #include <linux/spinlock.h> #include <linux/mm_types.h> +#include <linux/srcu.h> struct mmu_notifier; struct mmu_notifier_ops; |