Hi, Shakeel. On 08.06.2018 22:21, Shakeel Butt wrote: > On Tue, May 22, 2018 at 3:09 AM Kirill Tkhai <[email protected]> wrote: >> >> From: Vladimir Davydov <[email protected]> >> >> The patch makes shrink_slab() be called for root_mem_cgroup >> in the same way as it's called for the rest of cgroups. >> This simplifies the logic and improves the readability. >> >> Signed-off-by: Vladimir Davydov <[email protected]> >> ktkhai: Description written. >> Signed-off-by: Kirill Tkhai <[email protected]> >> --- >> mm/vmscan.c | 21 ++++++--------------- >> 1 file changed, 6 insertions(+), 15 deletions(-) >> >> diff --git a/mm/vmscan.c b/mm/vmscan.c >> index f26ca1e00efb..6dbc659db120 100644 >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -628,10 +628,8 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, >> int nid, >> * @nid is passed along to shrinkers with SHRINKER_NUMA_AWARE set, >> * unaware shrinkers will receive a node id of 0 instead. >> * >> - * @memcg specifies the memory cgroup to target. If it is not NULL, >> - * only shrinkers with SHRINKER_MEMCG_AWARE set will be called to scan >> - * objects from the memory cgroup specified. Otherwise, only unaware >> - * shrinkers are called. >> + * @memcg specifies the memory cgroup to target. Unaware shrinkers >> + * are called only if it is the root cgroup. >> * >> * @priority is sc->priority, we take the number of objects and >> by >> priority >> * in order to get the scan target. >> @@ -645,7 +643,7 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid, >> struct shrinker *shrinker; >> unsigned long freed = 0; >> > > Shouldn't there be a VM_BUG_ON(!memcg) here?
memcg can be NULL here in case of memory controller is disabled at boot parameters and in case of it's a global reclaim. So, such the check we can't add here. Thanks, Kirill
