diff options
| author | Matthew Wilcox <mawilcox@microsoft.com> | 2018-04-10 16:36:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-11 10:28:39 -0700 |
| commit | f6bb2a2c0b81c47282ddb7883f92e65a063c27dd (patch) | |
| tree | 74eb6dece48af9baee664a3abe1d70b5798f8b0d /kernel/pid.c | |
| parent | e5a955419642e0842fd26e1ada6ab3328018ca16 (diff) | |
xarray: add the xa_lock to the radix_tree_root
This results in no change in structure size on 64-bit machines as it
fits in the padding between the gfp_t and the void *. 32-bit machines
will grow the structure from 8 to 12 bytes. Almost all radix trees are
protected with (at least) a spinlock, so as they are converted from
radix trees to xarrays, the data structures will shrink again.
Initialising the spinlock requires a name for the benefit of lockdep, so
RADIX_TREE_INIT() now needs to know the name of the radix tree it's
initialising, and so do IDR_INIT() and IDA_INIT().
Also add the xa_lock() and xa_unlock() family of wrappers to make it
easier to use the lock. If we could rely on -fplan9-extensions in the
compiler, we could avoid all of this syntactic sugar, but that wasn't
added until gcc 4.6.
Link: http://lkml.kernel.org/r/20180313132639.17387-8-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/pid.c')
| -rw-r--r-- | kernel/pid.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/pid.c b/kernel/pid.c index ed6c343fe50d..157fe4b19971 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -70,7 +70,7 @@ int pid_max_max = PID_MAX_LIMIT; */ struct pid_namespace init_pid_ns = { .kref = KREF_INIT(2), - .idr = IDR_INIT, + .idr = IDR_INIT(init_pid_ns.idr), .pid_allocated = PIDNS_ADDING, .level = 0, .child_reaper = &init_task, |