path: root/include/linux/ipc.h
diff options
authorManfred Spraul <manfred@colorfullife.com>2017-07-12 14:34:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-12 16:26:01 -0700
commitdba4cdd39e698d8dcdad0656825423052ac90ccd (patch)
tree908f984f4652a42f603aac8f2db4edd059d11256 /include/linux/ipc.h
parent1a23395672658969a4035dcc518ea6cab835c579 (diff)
ipc: merge ipc_rcu and kern_ipc_perm
ipc has two management structures that exist for every id: - struct kern_ipc_perm, it contains e.g. the permissions. - struct ipc_rcu, it contains the rcu head for rcu handling and the refcount. The patch merges both structures. As a bonus, we may save one cacheline, because both structures are cacheline aligned. In addition, it reduces the number of casts, instead most codepaths can use container_of. To simplify code, the ipc_rcu_alloc initializes the allocation to 0. [manfred@colorfullife.com: really include the memset() into ipc_alloc_rcu()] Link: http://lkml.kernel.org/r/564f8612-0601-b267-514f-a9f650ec9b32@colorfullife.com Link: http://lkml.kernel.org/r/20170525185107.12869-3-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/ipc.h')
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/ipc.h b/include/linux/ipc.h
index 71fd92d81b26..5591f055e13f 100644
--- a/include/linux/ipc.h
+++ b/include/linux/ipc.h
@@ -20,6 +20,9 @@ struct kern_ipc_perm {
umode_t mode;
unsigned long seq;
void *security;
+ struct rcu_head rcu;
+ atomic_t refcount;
} ____cacheline_aligned_in_smp;
#endif /* _LINUX_IPC_H */