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| author |   John Stultz <john.stultz@linaro.org> | 2013-10-07 15:51:59 -0700 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2013-11-06 12:40:26 +0100 |
| commit | 1ca7d67cf5d5a2aef26a8d9afd789006fa098347 (patch) | |
| tree | 8f4f7d1f189d7a08983ab5ef522330f08f337459 /mm/filemap_xip.c | |
| parent | net: Explicitly initialize u64_stats_sync structures for lockdep (diff) | |
| download | linux-dev-1ca7d67cf5d5a2aef26a8d9afd789006fa098347.tar.xz linux-dev-1ca7d67cf5d5a2aef26a8d9afd789006fa098347.zip | |
seqcount: Add lockdep functionality to seqcount/seqlock structures
Currently seqlocks and seqcounts don't support lockdep.
After running across a seqcount related deadlock in the timekeeping
code, I used a less-refined and more focused variant of this patch
to narrow down the cause of the issue.
This is a first-pass attempt to properly enable lockdep functionality
on seqlocks and seqcounts.
Since seqcounts are used in the vdso gettimeofday code, I've provided
non-lockdep accessors for those needs.
I've also handled one case where there were nested seqlock writers
and there may be more edge cases.
Comments and feedback would be appreciated!
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm/filemap_xip.c')
| -rw-r--r-- | mm/filemap_xip.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c index 28fe26b64f8a..d8d9fe3f685c 100644 --- a/mm/filemap_xip.c +++ b/mm/filemap_xip.c @@ -26,7 +26,7 @@ * of ZERO_PAGE(), such as /dev/zero */ static DEFINE_MUTEX(xip_sparse_mutex); -static seqcount_t xip_sparse_seq = SEQCNT_ZERO; +static seqcount_t xip_sparse_seq = SEQCNT_ZERO(xip_sparse_seq); static struct page *__xip_sparse_page; /* called under xip_sparse_mutex */ |