The patch titled
ipc: recompute msgmni on ipc namespace creation/removal
has been added to the -mm tree. Its filename is
ipc-recompute-msgmni-on-ipc-namespace-creation-removal.patch
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------------------------------------------------------
Subject: ipc: recompute msgmni on ipc namespace creation/removal
From: Nadia Derbey <Nadia.Derbey@xxxxxxxx>
Introduce a notification mechanism that aims at recomputing msgmni each time
an ipc namespace is created or removed.
The ipc namespace notifier chain already defined for memory hotplug management
is used for that purpose too.
Each time a new ipc namespace is allocated or an existing ipc namespace is
removed, the ipcns notifier chain is notified. The callback routine for each
registered ipc namespace is then activated in order to recompute msgmni for
that namespace.
Signed-off-by: Nadia Derbey <Nadia.Derbey@xxxxxxxx>
Cc: Yasunori Goto <y-goto@xxxxxxxxxxxxxx>
Cc: Matt Helsley <matthltc@xxxxxxxxxx>
Cc: Mingming Cao <cmm@xxxxxxxxxx>
Cc: Pierre Peiffer <pierre.peiffer@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/ipc_namespace.h | 25 ++-----------------------
ipc/Makefile | 3 +--
ipc/ipcns_notifier.c | 2 ++
ipc/namespace.c | 12 ++++++++++++
4 files changed, 17 insertions(+), 25 deletions(-)
diff -puN include/linux/ipc_namespace.h~ipc-recompute-msgmni-on-ipc-namespace-creation-removal include/linux/ipc_namespace.h
--- a/include/linux/ipc_namespace.h~ipc-recompute-msgmni-on-ipc-namespace-creation-removal
+++ a/include/linux/ipc_namespace.h
@@ -4,14 +4,14 @@
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/rwsem.h>
-#ifdef CONFIG_MEMORY_HOTPLUG
#include <linux/notifier.h>
-#endif /* CONFIG_MEMORY_HOTPLUG */
/*
* ipc namespace events
*/
#define IPCNS_MEMCHANGED 0x00000001 /* Notify lowmem size changed */
+#define IPCNS_CREATED 0x00000002 /* Notify new ipc namespace created */
+#define IPCNS_REMOVED 0x00000003 /* Notify ipc namespace removed */
#define IPCNS_CALLBACK_PRI 0
@@ -42,9 +42,7 @@ struct ipc_namespace {
int shm_ctlmni;
int shm_tot;
-#ifdef CONFIG_MEMORY_HOTPLUG
struct notifier_block ipcns_nb;
-#endif
};
extern struct ipc_namespace init_ipc_ns;
@@ -53,29 +51,10 @@ extern atomic_t nr_ipc_ns;
#ifdef CONFIG_SYSVIPC
#define INIT_IPC_NS(ns) .ns = &init_ipc_ns,
-#ifdef CONFIG_MEMORY_HOTPLUG
-
extern int register_ipcns_notifier(struct ipc_namespace *);
extern int unregister_ipcns_notifier(struct ipc_namespace *);
extern int ipcns_notify(unsigned long);
-#else /* CONFIG_MEMORY_HOTPLUG */
-
-static inline int register_ipcns_notifier(struct ipc_namespace *ipcns)
-{
- return 0;
-}
-static inline int unregister_ipcns_notifier(struct ipc_namespace *ipcns)
-{
- return 0;
-}
-static inline int ipcns_notify(unsigned long ev)
-{
- return 0;
-}
-
-#endif /* CONFIG_MEMORY_HOTPLUG */
-
#else /* CONFIG_SYSVIPC */
#define INIT_IPC_NS(ns)
#endif /* CONFIG_SYSVIPC */
diff -puN ipc/Makefile~ipc-recompute-msgmni-on-ipc-namespace-creation-removal ipc/Makefile
--- a/ipc/Makefile~ipc-recompute-msgmni-on-ipc-namespace-creation-removal
+++ a/ipc/Makefile
@@ -3,8 +3,7 @@
#
obj-$(CONFIG_SYSVIPC_COMPAT) += compat.o
-obj_mem-$(CONFIG_MEMORY_HOTPLUG) += ipcns_notifier.o
-obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o $(obj_mem-y)
+obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o ipcns_notifier.o
obj-$(CONFIG_SYSVIPC_SYSCTL) += ipc_sysctl.o
obj_mq-$(CONFIG_COMPAT) += compat_mq.o
obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o $(obj_mq-y)
diff -puN ipc/ipcns_notifier.c~ipc-recompute-msgmni-on-ipc-namespace-creation-removal ipc/ipcns_notifier.c
--- a/ipc/ipcns_notifier.c~ipc-recompute-msgmni-on-ipc-namespace-creation-removal
+++ a/ipc/ipcns_notifier.c
@@ -29,6 +29,8 @@ static int ipcns_callback(struct notifie
switch (action) {
case IPCNS_MEMCHANGED: /* amount of lowmem has changed */
+ case IPCNS_CREATED:
+ case IPCNS_REMOVED:
/*
* It's time to recompute msgmni
*/
diff -puN ipc/namespace.c~ipc-recompute-msgmni-on-ipc-namespace-creation-removal ipc/namespace.c
--- a/ipc/namespace.c~ipc-recompute-msgmni-on-ipc-namespace-creation-removal
+++ a/ipc/namespace.c
@@ -26,6 +26,12 @@ static struct ipc_namespace *clone_ipc_n
msg_init_ns(ns);
shm_init_ns(ns);
+ /*
+ * msgmni has already been computed for the new ipc ns.
+ * Thus, do the ipcns creation notification before registering that
+ * new ipcns in the chain.
+ */
+ ipcns_notify(IPCNS_CREATED);
register_ipcns_notifier(ns);
kref_init(&ns->kref);
@@ -97,4 +103,10 @@ void free_ipc_ns(struct kref *kref)
shm_exit_ns(ns);
kfree(ns);
atomic_dec(&nr_ipc_ns);
+
+ /*
+ * Do the ipcns removal notification after decrementing nr_ipc_ns in
+ * order to have a correct value when recomputing msgmni.
+ */
+ ipcns_notify(IPCNS_REMOVED);
}
_
Patches currently in -mm which might be from Nadia.Derbey@xxxxxxxx are
origin.patch
ipc-use-ipc_buildid-directly-from-ipc_addid.patch
ipc-use-ipc_buildid-directly-from-ipc_addid-cleanup.patch
ipc-scale-msgmni-to-the-amount-of-lowmem.patch
ipc-scale-msgmni-to-the-number-of-ipc-namespaces.patch
ipc-define-the-slab_memory_callback-priority-as-a-constant.patch
ipc-recompute-msgmni-on-memory-add--remove.patch
ipc-invoke-the-ipcns-notifier-chain-as-a-work-item.patch
ipc-recompute-msgmni-on-ipc-namespace-creation-removal.patch
ipc-do-not-recompute-msgmni-anymore-if-explicitly-set-by-user.patch
ipc-re-enable-msgmni-automatic-recomputing-msgmni-if-set-to-negative.patch
-
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