Subject: [merged] ipc-utilc-ipc_rcu_alloc-cacheline-align-allocation.patch removed from -mm tree To: manfred@xxxxxxxxxxxxxxxx,davidlohr.bueso@xxxxxx,riel@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Tue, 09 Jul 2013 16:21:51 -0700 The patch titled Subject: ipc/util.c, ipc_rcu_alloc: cacheline align allocation has been removed from the -mm tree. Its filename was ipc-utilc-ipc_rcu_alloc-cacheline-align-allocation.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx> Subject: ipc/util.c, ipc_rcu_alloc: cacheline align allocation Enforce that ipc_rcu_alloc returns a cacheline aligned pointer on SMP. Rationale: The SysV sem code tries to move the main spinlock into a seperate cacheline (____cacheline_aligned_in_smp). This works only if ipc_rcu_alloc returns cacheline aligned pointers. vmalloc and kmalloc return cacheline algined pointers, the implementation of ipc_rcu_alloc breaks that. [akpm@xxxxxxxxxxxxxxxxxxxx: coding-style fixes] Signed-off-by: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Davidlohr Bueso <davidlohr.bueso@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- ipc/util.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff -puN ipc/util.c~ipc-utilc-ipc_rcu_alloc-cacheline-align-allocation ipc/util.c --- a/ipc/util.c~ipc-utilc-ipc_rcu_alloc-cacheline-align-allocation +++ a/ipc/util.c @@ -468,9 +468,7 @@ void ipc_free(void* ptr, int size) struct ipc_rcu { struct rcu_head rcu; atomic_t refcount; - /* "void *" makes sure alignment of following data is sane. */ - void *data[0]; -}; +} ____cacheline_aligned_in_smp; /** * ipc_rcu_alloc - allocate ipc and rcu space @@ -488,12 +486,14 @@ void *ipc_rcu_alloc(int size) if (unlikely(!out)) return NULL; atomic_set(&out->refcount, 1); - return out->data; + return out + 1; } int ipc_rcu_getref(void *ptr) { - return atomic_inc_not_zero(&container_of(ptr, struct ipc_rcu, data)->refcount); + struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1; + + return atomic_inc_not_zero(&p->refcount); } /** @@ -507,7 +507,7 @@ static void ipc_schedule_free(struct rcu void ipc_rcu_putref(void *ptr) { - struct ipc_rcu *p = container_of(ptr, struct ipc_rcu, data); + struct ipc_rcu *p = ((struct ipc_rcu *)ptr) - 1; if (!atomic_dec_and_test(&p->refcount)) return; _ Patches currently in -mm which might be from manfred@xxxxxxxxxxxxxxxx are origin.patch slab-leaks3-default-y.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