memcgroup: tidy up mem_cgroup_charge_common (3be91277) · Commits · 戴 / test

mm/memcontrol.c

+15 −29

Original line number	Diff line number	Diff line
		@@ -345,23 +345,22 @@ retry:
		goto done;
		}
		}

		unlock_page_cgroup(page);

		pc = kzalloc(sizeof(struct page_cgroup), gfp_mask);
		if (pc == NULL)
		goto err;

		rcu_read_lock();
		/*
		* We always charge the cgroup the mm_struct belongs to
		* the mm_struct's mem_cgroup changes on task migration if the
		* We always charge the cgroup the mm_struct belongs to.
		* The mm_struct's mem_cgroup changes on task migration if the
		* thread group leader migrates. It's possible that mm is not
		* set, if so charge the init_mm (happens for pagecache usage).
		*/
		if (!mm)
		mm = &init_mm;

		rcu_read_lock();
		mem = rcu_dereference(mm->mem_cgroup);
		/*
		* For every charge from the cgroup, increment reference
		@@ -375,12 +374,8 @@ retry:
		* the cgroup limit.
		*/
		while (res_counter_charge(&mem->res, PAGE_SIZE)) {
		bool is_atomic = gfp_mask & GFP_ATOMIC;
		/*
		* We cannot reclaim under GFP_ATOMIC, fail the charge
		*/
		if (is_atomic)
		goto noreclaim;
		if (!(gfp_mask & __GFP_WAIT))
		goto out;

		if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
		continue;
		@@ -394,23 +389,12 @@ retry:
		*/
		if (res_counter_check_under_limit(&mem->res))
		continue;
		/*
		* Since we control both RSS and cache, we end up with a
		* very interesting scenario where we end up reclaiming
		* memory (essentially RSS), since the memory is pushed
		* to swap cache, we eventually end up adding those
		* pages back to our list. Hence we give ourselves a
		* few chances before we fail
		*/
		else if (nr_retries--) {
		congestion_wait(WRITE, HZ/10);
		continue;

		if (!nr_retries--) {
		mem_cgroup_out_of_memory(mem, gfp_mask);
		goto out;
		}
		noreclaim:
		css_put(&mem->css);
		if (!is_atomic)
		mem_cgroup_out_of_memory(mem, GFP_KERNEL);
		goto free_pc;
		congestion_wait(WRITE, HZ/10);
		}

		atomic_set(&pc->ref_cnt, 1);
		@@ -419,10 +403,11 @@ noreclaim:
		pc->flags = 0;
		if (ctype == MEM_CGROUP_CHARGE_TYPE_CACHE)
		pc->flags \|= PAGE_CGROUP_FLAG_CACHE;

		if (page_cgroup_assign_new_page_cgroup(page, pc)) {
		/*
		* an another charge is added to this page already.
		* we do take lock_page_cgroup(page) again and read
		* Another charge has been added to this page already.
		* We take lock_page_cgroup(page) again and read
		* page->cgroup, increment refcnt.... just retry is OK.
		*/
		res_counter_uncharge(&mem->res, PAGE_SIZE);
		@@ -437,7 +422,8 @@ noreclaim:

		done:
		return 0;
		free_pc:
		out:
		css_put(&mem->css);
		kfree(pc);
		err:
		return -ENOMEM;

Admin message