Re: [PATCH] memcg: Remove memcg_cgroup::id from IDR on mem_cgroup_css_alloc() failure
From: Johannes Weiner <hannes@cmpxchg.org>
Date: 2018-07-30 15:28:22
Also in:
cgroups, lkml
Subsystem:
control group - memory resource controller (memcg), memory management, the rest · Maintainers:
Johannes Weiner, Michal Hocko, Roman Gushchin, Shakeel Butt, Andrew Morton, Linus Torvalds
On Sun, Jul 29, 2018 at 10:26:21PM +0300, Vladimir Davydov wrote:
On Fri, Jul 27, 2018 at 03:31:34PM -0400, Johannes Weiner wrote:quoted
That said, the lifetime of the root reference on the ID is the online state, we put that in css_offline. Is there a reason we need to have the ID ready and the memcg in the IDR before onlining it?I fail to see any reason for this in the code.
Me neither, thanks for double checking.
The patch also survives stress testing cgroup creation and destruction
with the script from 73f576c04b94 ("mm: memcontrol: fix cgroup
creation failure after many small jobs").
quoted
Can we do something like this and not mess with the alloc/free sequence at all?I guess so, and this definitely looks better to me.
Cool, then I think we should merge Kirill's patch as the fix and mine as a follow-up cleanup. ---