From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCHSET v2 cgroup/for-4.4] cgroup: make multi-process migration atomic Date: Fri, 11 Sep 2015 15:00:17 -0400 Message-ID: <1441998022-12953-1-git-send-email-tj@kernel.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id; bh=zkf6PJiTQUT9dGPykAWaiqGMudDd/qzY79hi/gBC06k=; b=pf70KNAl+QvsKw0/T7uLPf2hgqSgXhMBH03DHn43FnyVasYwwiRO7jLuE5lxPNttBQ T4xmqxdpyNg1ABofSm88UyLCulw03UCwocdde+jhIVkh9c0yrCCYvyN9cjPqUh8Gi4w8 QaZVH7tku+BctPWZNVcba4VBzqmi8Fu7/NqSiIjlA60XwtUBEXne9wUvdrKOcnsujuhV fiO3gwU+PoxngVDtnJOrnRQNiBQYP1oCqYFoab/AxUq5KoF2O7xdvxW4OpB5vLKhbC8+ 8QGKoKe88dpiDaobe9ZAI8mzJODhPyZAcW/Da4TdhP7GQnH99/7xX7/5yl9v0tUQAOC4 29ag== Sender: owner-linux-mm@kvack.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lizefan@huawei.com Cc: cgroups@vger.kernel.org, hannes@cmpxchg.org, mhocko@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org Hello, This is v2 of atomic multi-process migration patchset. This one slipped through crack somehow. Changes from the last take[L] are. * 0002-memcg-restructure-mem_cgroup_can_attach.patch already in upstream. * 0003-memcg-immigrate-charges-only-when-a-threadgroup-lead.patch dropped and 0004-cgroup-memcg-cpuset-implement-cgroup_taskset_for_eac.patch updated accordingly. * Li's acks added and patchset refreshed. When a controller is enabled or disabled on the unified hierarchy, the effective css changes for all processes in the sub-hierarchy which virtually is multi-process migration. This is implemented in cgroup_update_dfl_csses() as process-by-process migration - all the target source css_sets are first chained to the target list and processes are drained from them one-by-one. If a process gets rejected by a controller after some are successfully migrated, the recovery action is tricky. The changes which have happened upto this point have to be rolled back but there's nothing guaranteeing such rollback would be successful either. The unified hierarchy didn't need to deal with this issue because organizational operations were expected to always succeed; unfortunately, it turned out that such policy doesn't work too well for certain type of resources and unified hierarchy would need to allow migration failures for some restrictied cases. This patch updates multi-process migration in cgroup_update_dfl_csses() atomic so that ->can_attach() can fail the whole transaction. It's consisted of the following seven patches. 0001-cpuset-migrate-memory-only-for-threadgroup-leaders.patch 0002-cgroup-memcg-cpuset-implement-cgroup_taskset_for_eac.patch 0003-reorder-cgroup_migrate-s-parameters.patch 0004-cgroup-separate-out-taskset-operations-from-cgroup_m.patch 0005-cgroup-make-cgroup_update_dfl_csses-migrate-all-targ.patch 0001-0002 prepare cpuset and memcg. Note that 0001 causes behavioral changes in that mm is now always tied to the threadgroup leader. Avoiding this change isn't too difficult but both the code and behavior are saner this way and the change is unlikely to cause breakage. 0003-0005 prepare and implement atomic multi-process migration. This patchset is on top of 64d1def7d338 ("Merge tag 'sound-fix-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound"). and available in the following git branch. git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git review-multi-process-migration diffstat follows. Thanks. include/linux/cgroup.h | 22 +++ kernel/cgroup.c | 278 ++++++++++++++++++++++++------------------------- kernel/cpuset.c | 41 +++---- mm/memcontrol.c | 17 ++ 4 files changed, 198 insertions(+), 160 deletions(-) -- tejun [L] http://lkml.kernel.org/g/1431978595-12176-1-git-send-email-tj@kernel.org -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org