diff options
| author | Sagi Grimberg <sagig@mellanox.co.il> | 2012-10-08 16:29:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-09 16:22:23 +0900 |
| commit | 21a92735f660eaecf69a6f2e777f18463760ec32 (patch) | |
| tree | 15299bab0280cfccfce1d97168234411cb4799b8 /mm/nommu.c | |
| parent | 48af0d7cb3c87fae2ff38af372821dcb0b019c9e (diff) | |
| download | linux-21a92735f660eaecf69a6f2e777f18463760ec32.tar.bz2 | |
mm: mmu_notifier: have mmu_notifiers use a global SRCU so they may safely schedule
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>
Diffstat (limited to 'mm/nommu.c')
0 files changed, 0 insertions, 0 deletions