diff options
| author | Sagi Grimberg <sagig@mellanox.co.il> | 2012-10-08 16:29:24 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-02-28 06:59:00 -0800 |
| commit | 4209ee0d3f7992af3903b5f9a3359f6d2f597c4b (patch) | |
| tree | 5009887555ccf68907acf7ff9b14c9acfed6ee00 /mm/sparse-vmemmap.c | |
| parent | 362efcc9b0ba020f9124c70c56381ed64491aeca (diff) | |
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 'mm/sparse-vmemmap.c')
0 files changed, 0 insertions, 0 deletions