This is where the mm_autonuma structure is being handled. Just like
sched_autonuma, this is only allocated at runtime if the hardware the
kernel is running on has been detected as NUMA. On not NUMA hardware
the memory cost is reduced to one pointer per mm.
To get rid of the pointer in the each mm, the kernel can be compiled
with CONFIG_AUTONUMA=n.
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
---
kernel/fork.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index d323eb1..22f102e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -526,6 +526,8 @@ static void mm_init_aio(struct mm_struct *mm)
static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
{
+ if (unlikely(alloc_mm_autonuma(mm)))
+ goto out_free_mm;
atomic_set(&mm->mm_users, 1);
atomic_set(&mm->mm_count, 1);
init_rwsem(&mm->mmap_sem);
@@ -548,6 +550,8 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
return mm;
}
+ free_mm_autonuma(mm);
+out_free_mm:
free_mm(mm);
return NULL;
}
@@ -597,6 +601,7 @@ void __mmdrop(struct mm_struct *mm)
destroy_context(mm);
mmu_notifier_mm_destroy(mm);
check_mm(mm);
+ free_mm_autonuma(mm);
free_mm(mm);
}
EXPORT_SYMBOL_GPL(__mmdrop);
@@ -880,6 +885,7 @@ fail_nocontext:
* If init_new_context() failed, we cannot use mmput() to free the mm
* because it calls destroy_context()
*/
+ free_mm_autonuma(mm);
mm_free_pgd(mm);
free_mm(mm);
return NULL;
@@ -1706,6 +1712,7 @@ void __init proc_caches_init(void)
mm_cachep = kmem_cache_create("mm_struct",
sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
+ mm_autonuma_init();
vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC);
mmap_init();
nsproxy_cache_init();
--
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