From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 2/7] memcg: restructure mem_cgroup_can_attach() Date: Mon, 18 May 2015 15:49:50 -0400 Message-ID: <1431978595-12176-3-git-send-email-tj@kernel.org> References: <1431978595-12176-1-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:in-reply-to:references; bh=L1nJWeQ77svQ0iJsNBm0gzSuSIh1Xjx678tUwIBGiI4=; b=URWDG+gFjxBOCf1jWQ/c7z7ou2pjswMLnaBL6jYlDoJ6NVGbv3ZZszW/aDv1+Ms8L+ MiJ/liJQ3HpigwGS2HE5Op9mL0uBPb1yHAtQ2j/CDiEWvalzkUE3prgSyN0LAsws5+jR qgfHDhkRWK+FGu72n45lKivpsCUYByQAcCtnTjqW5xy6lh3PyO+DohBtGMVvMJjAsAEf hpHfi8ktDsJz/jAHOYGHlH4U+t9UXlrr7C9EPzB19MTrhWkeXBpyuoca3eOg3wLaglCl tdMD3tGpFJlGKAavpOIwuaMdcrbfFbYngYIxE+e2FGi4PvHyKxgH3e6ShQ2afIKFkjiQ Utzg== In-Reply-To: <1431978595-12176-1-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, mhocko-AlSwsSmVLrQ@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Tejun Heo Restructure it to lower nesting level and help the planned threadgroup leader iteration changes. This is pure reorganization. Signed-off-by: Tejun Heo Cc: Johannes Weiner Cc: Michal Hocko --- mm/memcontrol.c | 61 ++++++++++++++++++++++++++++++--------------------------- 1 file changed, 32 insertions(+), 29 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 14c2f20..b1b834d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4997,10 +4997,12 @@ static void mem_cgroup_clear_mc(void) static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, struct cgroup_taskset *tset) { - struct task_struct *p = cgroup_taskset_first(tset); - int ret = 0; struct mem_cgroup *memcg = mem_cgroup_from_css(css); + struct mem_cgroup *from; + struct task_struct *p; + struct mm_struct *mm; unsigned long move_flags; + int ret = 0; /* * We are now commited to this value whatever it is. Changes in this @@ -5008,36 +5010,37 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, * So we need to save it, and keep it going. */ move_flags = READ_ONCE(memcg->move_charge_at_immigrate); - if (move_flags) { - struct mm_struct *mm; - struct mem_cgroup *from = mem_cgroup_from_task(p); + if (!move_flags) + return 0; - VM_BUG_ON(from == memcg); + p = cgroup_taskset_first(tset); + from = mem_cgroup_from_task(p); - mm = get_task_mm(p); - if (!mm) - return 0; - /* We move charges only when we move a owner of the mm */ - if (mm->owner == p) { - VM_BUG_ON(mc.from); - VM_BUG_ON(mc.to); - VM_BUG_ON(mc.precharge); - VM_BUG_ON(mc.moved_charge); - VM_BUG_ON(mc.moved_swap); - - spin_lock(&mc.lock); - mc.from = from; - mc.to = memcg; - mc.flags = move_flags; - spin_unlock(&mc.lock); - /* We set mc.moving_task later */ - - ret = mem_cgroup_precharge_mc(mm); - if (ret) - mem_cgroup_clear_mc(); - } - mmput(mm); + VM_BUG_ON(from == memcg); + + mm = get_task_mm(p); + if (!mm) + return 0; + /* We move charges only when we move a owner of the mm */ + if (mm->owner == p) { + VM_BUG_ON(mc.from); + VM_BUG_ON(mc.to); + VM_BUG_ON(mc.precharge); + VM_BUG_ON(mc.moved_charge); + VM_BUG_ON(mc.moved_swap); + + spin_lock(&mc.lock); + mc.from = from; + mc.to = memcg; + mc.flags = move_flags; + spin_unlock(&mc.lock); + /* We set mc.moving_task later */ + + ret = mem_cgroup_precharge_mc(mm); + if (ret) + mem_cgroup_clear_mc(); } + mmput(mm); return ret; } -- 2.4.0