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| author |   Hugh Dickins <hughd@google.com> | 2010-08-25 23:12:54 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-28 13:54:12 -0700 |
| commit | f18194275c39835cb84563500995e0d503a32d9a (patch) | |
| tree | ec3221ba856e6580e844c4bff200c48f2618c6ac /tools/perf/util/trace-event-scripting.c | |
| parent | Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip (diff) | |
| download | wireguard-linux-f18194275c39835cb84563500995e0d503a32d9a.tar.xz wireguard-linux-f18194275c39835cb84563500995e0d503a32d9a.zip | |
mm: fix hang on anon_vma->root->lock
After several hours, kbuild tests hang with anon_vma_prepare() spinning on
a newly allocated anon_vma's lock - on a box with CONFIG_TREE_PREEMPT_RCU=y
(which makes this very much more likely, but it could happen without).
The ever-subtle page_lock_anon_vma() now needs a further twist: since
anon_vma_prepare() and anon_vma_fork() are liable to change the ->root
of a reused anon_vma structure at any moment, page_lock_anon_vma()
needs to check page_mapped() again before succeeding, otherwise
page_unlock_anon_vma() might address a different root->lock.
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/perf/util/trace-event-scripting.c')
0 files changed, 0 insertions, 0 deletions