Subject: + ipcmsg-introduce-lockless-functions-to-obtain-the-ipc-object.patch added to -mm tree To: davidlohr.bueso@xxxxxx,andi@xxxxxxxxxxxxxx,riel@xxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Fri, 24 May 2013 13:17:40 -0700 The patch titled Subject: ipc,msg: introduce lockless functions to obtain the ipc object has been added to the -mm tree. Its filename is ipcmsg-introduce-lockless-functions-to-obtain-the-ipc-object.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Davidlohr Bueso <davidlohr.bueso@xxxxxx> Subject: ipc,msg: introduce lockless functions to obtain the ipc object Add msq_obtain_object() and msq_obtain_object_check(), which will allow us to get the ipc object without acquiring the lock. Just as with semaphores, these functions are basically wrappers around ipc_obtain_object*(). Signed-off-by: Davidlohr Bueso <davidlohr.bueso@xxxxxx> Cc: Andi Kleen <andi@xxxxxxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- ipc/msg.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff -puN ipc/msg.c~ipcmsg-introduce-lockless-functions-to-obtain-the-ipc-object ipc/msg.c --- a/ipc/msg.c~ipcmsg-introduce-lockless-functions-to-obtain-the-ipc-object +++ a/ipc/msg.c @@ -166,6 +166,27 @@ static inline struct msg_queue *msg_lock return container_of(ipcp, struct msg_queue, q_perm); } +static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id) +{ + struct kern_ipc_perm *ipcp = ipc_obtain_object(&msg_ids(ns), id); + + if (IS_ERR(ipcp)) + return ERR_CAST(ipcp); + + return container_of(ipcp, struct msg_queue, q_perm); +} + +static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns, + int id) +{ + struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id); + + if (IS_ERR(ipcp)) + return ERR_CAST(ipcp); + + return container_of(ipcp, struct msg_queue, q_perm); +} + static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) { ipc_rmid(&msg_ids(ns), &s->q_perm); _ Patches currently in -mm which might be from davidlohr.bueso@xxxxxx are linux-next.patch shm-fix-null-pointer-deref-when-userspace-specifies-invalid-hugepage-size-fix.patch softirq-use-_ret_ip_.patch ipc-move-rcu-lock-out-of-ipc_addid.patch ipc-introduce-ipc-object-locking-helpers.patch ipc-close-open-coded-spin-lock-calls.patch ipc-move-locking-out-of-ipcctl_pre_down_nolock.patch ipcmsg-shorten-critical-region-in-msgctl_down.patch ipcmsg-introduce-msgctl_nolock.patch ipcmsg-introduce-lockless-functions-to-obtain-the-ipc-object.patch ipcmsg-make-msgctl_nolock-lockless.patch ipcmsg-shorten-critical-region-in-msgsnd.patch ipcmsg-shorten-critical-region-in-msgrcv.patch ipc-remove-unused-functions.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html