The patch titled Subject: mm/mmu_notifier: init notifier if necessary has been removed from the -mm tree. Its filename was mm-mmu_notifier-init-notifier-if-necessary.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx> Subject: mm/mmu_notifier: init notifier if necessary While registering MMU notifier, new instance of MMU notifier_mm will be allocated and later free'd if currrent mm_struct's MMU notifier_mm has been initialized. That causes some overhead. The patch tries to elominate that. Signed-off-by: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx> Signed-off-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Avi Kivity <avi@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx> Cc: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx> Cc: Sagi Grimberg <sagig@xxxxxxxxxxxxxx> Cc: Haggai Eran <haggaie@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mmu_notifier.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff -puN mm/mmu_notifier.c~mm-mmu_notifier-init-notifier-if-necessary mm/mmu_notifier.c --- a/mm/mmu_notifier.c~mm-mmu_notifier-init-notifier-if-necessary +++ a/mm/mmu_notifier.c @@ -207,22 +207,23 @@ static int do_mmu_notifier_register(stru */ BUG_ON(!srcu.per_cpu_ref); - ret = -ENOMEM; - mmu_notifier_mm = kmalloc(sizeof(struct mmu_notifier_mm), GFP_KERNEL); - if (unlikely(!mmu_notifier_mm)) - goto out; - if (take_mmap_sem) down_write(&mm->mmap_sem); ret = mm_take_all_locks(mm); if (unlikely(ret)) - goto out_cleanup; + goto out; if (!mm_has_notifiers(mm)) { + mmu_notifier_mm = kmalloc(sizeof(struct mmu_notifier_mm), + GFP_KERNEL); + if (unlikely(!mmu_notifier_mm)) { + ret = -ENOMEM; + goto out_of_mem; + } INIT_HLIST_HEAD(&mmu_notifier_mm->list); spin_lock_init(&mmu_notifier_mm->lock); + mm->mmu_notifier_mm = mmu_notifier_mm; - mmu_notifier_mm = NULL; } atomic_inc(&mm->mm_count); @@ -238,13 +239,12 @@ static int do_mmu_notifier_register(stru hlist_add_head(&mn->hlist, &mm->mmu_notifier_mm->list); spin_unlock(&mm->mmu_notifier_mm->lock); +out_of_mem: mm_drop_all_locks(mm); -out_cleanup: +out: if (take_mmap_sem) up_write(&mm->mmap_sem); - /* kfree() does nothing if mmu_notifier_mm is NULL */ - kfree(mmu_notifier_mm); -out: + BUG_ON(atomic_read(&mm->mm_users) <= 0); return ret; } _ Patches currently in -mm which might be from shangw@xxxxxxxxxxxxxxxxxx are origin.patch mm-slab-remove-duplicate-check.patch mm-memblock-reduce-overhead-in-binary-search.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