Naoya-san reports that hugetlb pages now get charged as file cache, which wreaks all kinds of havoc during migration, uncharge etc.
The file-specific charge path used to filter PageCompound(), but it wasn't commented and so it got lost when unifying the charge paths. We can't add PageCompound() back into a unified charge path because of THP, so filter huge pages directly in add_to_page_cache(). Reported-by: Naoya Horiguchi <[email protected]> Signed-off-by: Johannes Weiner <[email protected]> --- mm/filemap.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 114cd89c1cc2..c088ac01e856 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -31,6 +31,7 @@ #include <linux/security.h> #include <linux/cpuset.h> #include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */ +#include <linux/hugetlb.h> #include <linux/memcontrol.h> #include <linux/cleancache.h> #include <linux/rmap.h> @@ -560,19 +561,24 @@ static int __add_to_page_cache_locked(struct page *page, pgoff_t offset, gfp_t gfp_mask, void **shadowp) { + int huge = PageHuge(page); struct mem_cgroup *memcg; int error; VM_BUG_ON_PAGE(!PageLocked(page), page); VM_BUG_ON_PAGE(PageSwapBacked(page), page); - error = mem_cgroup_try_charge(page, current->mm, gfp_mask, &memcg); - if (error) - return error; + if (!huge) { + error = mem_cgroup_try_charge(page, current->mm, + gfp_mask, &memcg); + if (error) + return error; + } error = radix_tree_maybe_preload(gfp_mask & ~__GFP_HIGHMEM); if (error) { - mem_cgroup_cancel_charge(page, memcg); + if (!huge) + mem_cgroup_cancel_charge(page, memcg); return error; } @@ -587,14 +593,16 @@ static int __add_to_page_cache_locked(struct page *page, goto err_insert; __inc_zone_page_state(page, NR_FILE_PAGES); spin_unlock_irq(&mapping->tree_lock); - mem_cgroup_commit_charge(page, memcg, false); + if (!huge) + mem_cgroup_commit_charge(page, memcg, false); trace_mm_filemap_add_to_page_cache(page); return 0; err_insert: page->mapping = NULL; /* Leave page->index set: truncation relies upon it */ spin_unlock_irq(&mapping->tree_lock); - mem_cgroup_cancel_charge(page, memcg); + if (!huge) + mem_cgroup_cancel_charge(page, memcg); page_cache_release(page); return error; } -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
