[PATCH RFC 5/5] vm_cgroup: do not charge tasks in root cgroup
From: Vladimir Davydov <hidden>
Date: 2014-07-03 12:49:50
Also in:
linux-mm, lkml
Subsystem:
memory management, the rest · Maintainers:
Andrew Morton, Linus Torvalds
For the root cgroup (the whole system), we already have overcommit accounting and control, so we can skip charging tasks in the root cgroup to avoid overhead. Signed-off-by: Vladimir Davydov <redacted> --- mm/vm_cgroup.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/mm/vm_cgroup.c b/mm/vm_cgroup.c
index 6642f934540a..c871fecaab4c 100644
--- a/mm/vm_cgroup.c
+++ b/mm/vm_cgroup.c@@ -1,6 +1,7 @@ #include <linux/cgroup.h> #include <linux/res_counter.h> #include <linux/mm.h> +#include <linux/mman.h> #include <linux/slab.h> #include <linux/rcupdate.h> #include <linux/shmem_fs.h>
@@ -65,6 +66,9 @@ static int vm_cgroup_do_charge(struct vm_cgroup *vmcg, unsigned long val = nr_pages << PAGE_SHIFT; struct res_counter *fail_res; + if (vm_cgroup_is_root(vmcg)) + return 0; + return res_counter_charge(&vmcg->res, val, &fail_res); }
@@ -73,6 +77,9 @@ static void vm_cgroup_do_uncharge(struct vm_cgroup *vmcg, { unsigned long val = nr_pages << PAGE_SHIFT; + if (vm_cgroup_is_root(vmcg)) + return; + res_counter_uncharge(&vmcg->res, val); }
@@ -159,6 +166,9 @@ static u64 vm_cgroup_read_u64(struct cgroup_subsys_state *css, struct vm_cgroup *vmcg = vm_cgroup_from_css(css); int memb = cft->private; + if (vm_cgroup_is_root(vmcg)) + return vm_memory_committed() << PAGE_SHIFT; + return res_counter_read_u64(&vmcg->res, memb); }
--
1.7.10.4