On Wed, 9 Dec 2015 13:58:58 -0500 Johannes Weiner [off-list ref] wrote:

quoted

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6faea81e66d7..73cd572167bb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c

@@ -4220,13 +4220,13 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
 	if (ret)
 		return ret;
 
+#ifdef CONFIG_INET
 #ifdef CONFIG_MEMCG_LEGACY_KMEM
 	ret = tcp_init_cgroup(memcg);
 	if (ret)
 		return ret;
 #endif

The calls to tcp_init_cgroup() appear earlier in the series than "mm:
memcontrol: hook up vmpressure to socket pressure". However, they get
moved around a few times so fixing it earlier means respinning the
series. Andrew, it's up to you whether we take the bisectability hit
for !CONFIG_INET && CONFIG_MEMCG (how common is this?) or whether you
want me to resend the series.

hm, drat, I was suspecting dependency issues here, but a test build
said it was OK.

Actually, I was expecting this patch series to depend on the linux-next
cgroup2 changes, but that doesn't appear to be the case.  *should* this
series be staged after the cgroup2 code?

Regarding this particular series: yes, I think we can live with a
bisection hole for !CONFIG_INET && CONFIG_MEMCG users.  But I'm not
sure why we're discussing bisection issues, because Arnd's build
failure occurs with everything applied?

Sorry about the trouble. I don't have a git tree on kernel.org because
we don't really use git in -mm, but the downside is that we don't get
the benefits of the automatic build testing for all kinds of configs.
I'll try to set up a git tree to expose series to full build coverage
before they hit -mm and -next.

This sort of thing happens quite rarely.