Re: [PATCH 1/5] mm: memcontrol: generalize locking for the page->mem_cgroup binding
From: Vladimir Davydov <hidden>
Date: 2016-01-27 14:31:01
Also in:
linux-mm, lkml
On Tue, Jan 26, 2016 at 04:00:02PM -0500, Johannes Weiner wrote:
quoted hunk ↗ jump to hunk
@@ -683,17 +683,17 @@ int __set_page_dirty_buffers(struct page *page) } while (bh != head); } /* - * Use mem_group_begin_page_stat() to keep PageDirty synchronized with - * per-memcg dirty page counters. + * Lock out page->mem_cgroup migration to keep PageDirty + * synchronized with per-memcg dirty page counters. */ - memcg = mem_cgroup_begin_page_stat(page); + memcg = lock_page_memcg(page); newly_dirty = !TestSetPageDirty(page); spin_unlock(&mapping->private_lock); if (newly_dirty) __set_page_dirty(page, mapping, memcg, 1);
Do we really want to pass memcg to __set_page_dirty and then to account_page_dirtied, increasing stack/regs usage even in case memory cgroup is disabled? May be, it'd be better to make mem_cgroup_update_page_stat take a page instead of a memcg? Thanks, Vladimir
- mem_cgroup_end_page_stat(memcg); + unlock_page_memcg(memcg); if (newly_dirty) __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);