From 0dd1c7bbce8d1d142bb25aefaa50262dfd77cb78 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Tue, 21 Jan 2014 15:49:49 -0800 Subject: mm/rmap: extend rmap_walk_xxx() to cope with different cases There are a lot of common parts in traversing functions, but there are also a little of uncommon parts in it. By assigning proper function pointer on each rmap_walker_control, we can handle these difference correctly. Following are differences we should handle. 1. difference of lock function in anon mapping case 2. nonlinear handling in file mapping case 3. prechecked condition: checking memcg in page_referenced(), checking VM_SHARE in page_mkclean() checking temporary vma in try_to_unmap() 4. exit condition: checking page_mapped() in try_to_unmap() So, in this patch, I introduce 4 function pointers to handle above differences. Signed-off-by: Joonsoo Kim Cc: Naoya Horiguchi Cc: Mel Gorman Cc: Hugh Dickins Cc: Rik van Riel Cc: Ingo Molnar Cc: Hillf Danton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/ksm.c | 7 +++++++ mm/rmap.c | 37 +++++++++++++++++++++++++++++-------- 2 files changed, 36 insertions(+), 8 deletions(-) (limited to 'mm') diff --git a/mm/ksm.c b/mm/ksm.c index c3035fee8080..91b8cb35f7cc 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -2032,12 +2032,19 @@ again: if ((rmap_item->mm == vma->vm_mm) == search_new_forks) continue; + if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg)) + continue; + ret = rwc->rmap_one(page, vma, rmap_item->address, rwc->arg); if (ret != SWAP_AGAIN) { anon_vma_unlock_read(anon_vma); goto out; } + if (rwc->done && rwc->done(page)) { + anon_vma_unlock_read(anon_vma); + goto out; + } } anon_vma_unlock_read(anon_vma); } diff --git a/mm/rmap.c b/mm/rmap.c index f8f10ad5d359..97bf8f0396f8 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1684,10 +1684,14 @@ void __put_anon_vma(struct anon_vma *anon_vma) } #ifdef CONFIG_MIGRATION -static struct anon_vma *rmap_walk_anon_lock(struct page *page) +static struct anon_vma *rmap_walk_anon_lock(struct page *page, + struct rmap_walk_control *rwc) { struct anon_vma *anon_vma; + if (rwc->anon_lock) + return rwc->anon_lock(page); + /* * Note: remove_migration_ptes() cannot use page_lock_anon_vma_read() * because that depends on page_mapped(); but not all its usages @@ -1713,16 +1717,22 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc) struct anon_vma_chain *avc; int ret = SWAP_AGAIN; - anon_vma = rmap_walk_anon_lock(page); + anon_vma = rmap_walk_anon_lock(page, rwc); if (!anon_vma) return ret; anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) { struct vm_area_struct *vma = avc->vma; unsigned long address = vma_address(page, vma); + + if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg)) + continue; + ret = rwc->rmap_one(page, vma, address, rwc->arg); if (ret != SWAP_AGAIN) break; + if (rwc->done && rwc->done(page)) + break; } anon_vma_unlock_read(anon_vma); return ret; @@ -1740,15 +1750,26 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc) mutex_lock(&mapping->i_mmap_mutex); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { unsigned long address = vma_address(page, vma); + + if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg)) + continue; + ret = rwc->rmap_one(page, vma, address, rwc->arg); if (ret != SWAP_AGAIN) - break; + goto done; + if (rwc->done && rwc->done(page)) + goto done; } - /* - * No nonlinear handling: being always shared, nonlinear vmas - * never contain migration ptes. Decide what to do about this - * limitation to linear when we need rmap_walk() on nonlinear. - */ + + if (!rwc->file_nonlinear) + goto done; + + if (list_empty(&mapping->i_mmap_nonlinear)) + goto done; + + ret = rwc->file_nonlinear(page, mapping, vma); + +done: mutex_unlock(&mapping->i_mmap_mutex); return ret; } -- cgit v1.2.3